Chemical change is a process that involves recombining atoms and energy flows
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Chemical change is a process that involves recombining atoms and energy flows. Unit A: Chemistry. In this unit, you will learn about.

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In this unit you will learn about
In this unit, you will learn about... and energy flows.

  • General Outcome #3 – Identify and classify chemical changes, and write word and balanced chemical equations for significant chemical reactions, as applications of Lavoisier’s law for conservation of mass

    • ROCK – describe the evidence for chemical changes (energy change, formation of gas or precipitate, color or odour change, change in temperature)

    • ROCK – differentiate between endothermic and exothermic chemical reactions


  • ROCK – translate word equations to balanced chemical equations and vice versa for chemical reactions that occur in living and non living systems

  • ROCK – classify and identify categories of chemical reactions (formation, decomposition, hydrocarbon combustion, single replacement, double replacement)

  • ROCK – predict the products of formation (synthesis) and decomposition, single and double replacement and hydrocarbon combustion chemical reactions, when given the reactants

  • ROCK – interpret balanced chemical equations in terms of moles of chemical species and relate the mole concept to the law of conservation of mass

  • SAND – identify chemical reactions that are significant in societies

  • SAND – define the mole as the amount of an element containing 6.02 X 1023 atoms (Avogadro’s number) and apply the concept to calculate quantifies of substances of other chemical species

  • SAND – provide examples of household, commercial and industrial processes that use chemical reactions to produce useful substances and energy


The ultimate chemical reaction
The Ultimate Chemical Reaction equations and vice versa for chemical reactions that occur in living and non living systems

  • What do you think would be one of the coolest things to experience??


A3 1 important examples of chemical change

A3.1: Important Examples of Chemical Change equations and vice versa for chemical reactions that occur in living and non living systems

Unit A: chemistry


In this section you will learn about
In this section, you will learn about... equations and vice versa for chemical reactions that occur in living and non living systems

  • General Outcome #3 – Identify and classify chemical changes, and write word and balanced chemical equations for significant chemical reactions, as applications of Lavoisier’s law for conservation of mass

    • ROCK – describe the evidence for chemical changes (energy change, formation of gas or precipitate, color or odour change, change in temperature)

    • ROCK – differentiate between endothermic and exothermic chemical reactions

    • SAND – identify chemical reactions that are significant in societies

    • SAND – provide examples of household, commercial and industrial processes that use chemical reactions to produce useful substances and energy


Did you know
Did you know?? equations and vice versa for chemical reactions that occur in living and non living systems

  • Slicing an onion causes your eyes to sting because of a chemical reaction. Slicing ruptures the onion’s cells allowing substances to mix. A gas is produced and reacts with the water in your eyes – producing dilute sulfuric acid!


Important examples of chemical change
Important Examples of Chemical Change equations and vice versa for chemical reactions that occur in living and non living systems

  • When was the last time you watched an awesome display of fireworks? Fireworks is one example of chemical change (occurs when a substance or substances react in a chemical reaction to create a different substance or substances) occurring. Other examples of chemical change include dough rising, the changing taste of food cooking on a barbecue, the combustion of fuel in a motor vehicle, a glowing glow stick, and the changing temperature of a hot or cold pack.


Important examples of chemical change1
Important Examples of Chemical Change equations and vice versa for chemical reactions that occur in living and non living systems

  • The substances that react are called reactants and the new substances that are produced are called products

  • The products have completely different properties than the reactants


Energy flow through systems
Energy Flow through Systems equations and vice versa for chemical reactions that occur in living and non living systems

  • On p. 79, answer Minds On... questions 1-4


Energy flow through systems1
Energy Flow through Systems equations and vice versa for chemical reactions that occur in living and non living systems

  • Which of these processes involve a release of energy?

    • Fireworks (a) and the glow stick (d) involve a release of energy. Fireworks release heat, light, and sound energy. The glow stick releases light energy.

  • Which involve the absorption of energy?

    • The boiling water (b) and the baking (c) involve the absorption of energy. Both absorb heat energy produced by a gas flame or an electric current passing through an element.


  • Energy flow through systems2
    Energy Flow through Systems equations and vice versa for chemical reactions that occur in living and non living systems

    • Which are chemical changes?

      • Chemical change involves a change to the composition of the substance. Therefore, chemical changes occur in (a), (c), and (d).

  • Which are physical changes?

    • Physical change involves a change of state (e.g., liquid to gas). A physical change occurs in (b).


  • Reactions that form gases
    Reactions That Form Gases equations and vice versa for chemical reactions that occur in living and non living systems

    • Recall: evidence of chemical reactions include the formation of gases and precipitates.

    • Familiar examples of chemical reactions that result in the formation of gases are breads and cakes rising and the inflation of an automobile air bag.


    Reactions that form solids
    Reactions That Form Solids equations and vice versa for chemical reactions that occur in living and non living systems

    • Some reactions form a solid that hardens over a short period of time. Epoxy glue is one example.


    Showing states in chemical formulas
    Showing States in Chemical Formulas equations and vice versa for chemical reactions that occur in living and non living systems

    • Recall: (s), (l), (g), (aq) are the subscripts that refer to the substances state at room temperature. It is important to always give as much information as possible about a reaction.

    • The following are guidelines for the states of substances at room temperature


    Showing states in chemical formulas1
    Showing States in Chemical Formulas equations and vice versa for chemical reactions that occur in living and non living systems

    • Elements

      • Metals are solid, except mercury, which is a liquid

      • Most of the diatomic elements are gases H2(g), N2(g), O2(g), F2(g) and Cl2(g). Bromine is a liquid and iodine is a solid: Br2(l) and I2(s)

      • Sulfur, phosphorus and carbon are solids


    Showing states in chemical formulas2
    Showing States in Chemical Formulas equations and vice versa for chemical reactions that occur in living and non living systems

    • Compounds

      • All ionic compounds are solid at room temperature

      • An ionic compound that is very soluble is shown as aqueous when it is dissolved in water. An ionic compound that is slightly soluble is usually shown as solid, even when it’s in water.

      • Molecular compounds are very difficult to predict. The smaller the molecules are, the more they tend to be gases. The larger they are, the more they tend to be liquids and solids. For example, CH4(g) is a gas (natural gas), C6H14(l) is a liquid component of gasoline and C18H38(s) is bees wax.


    Energy changes
    Energy Changes equations and vice versa for chemical reactions that occur in living and non living systems

    • Energy flow is an essential part of any chemical reaction, sometimes energy is absorbed and other times energy is released.


    Exothermic reactions
    Exothermic Reactions equations and vice versa for chemical reactions that occur in living and non living systems

    • THE AUTOMOTIVE BATTERYA lead-acid storage battery is an electrochemical device that produces voltage and delivers electrical current. The battery is the primary "source" of electrical energy used in vehicles today. It's important to remember that a battery does not store electricity, but rather it stores a series of chemicals, and through a chemical process electricity is produced. Basically, two different types of lead in an acid mixture react to produce an electrical pressure called voltage. This electrochemical reaction changes chemical energy to electrical energy and is the basis for all automotive batteries.

    • Exothermic reactions – chemical reaction that release energy usually in the form of heat, light or electricity


    Exothermic reactions1
    Exothermic Reactions equations and vice versa for chemical reactions that occur in living and non living systems

    • Another important exothermic reaction is the combustion of fossil fuels: coal, oil and natural gas

    • Combustion – chemical reaction that occurs when oxygen reacts rapidly with a substance to form a new substance and gives off energy (also called “burning”)


    Exothermic reactions2
    Exothermic Reactions equations and vice versa for chemical reactions that occur in living and non living systems

    • For example, coal is used to produce electricity, the heat released by coal combustion is used to make steam, which drives turbines that produce electricity.

    • This process produces carbon dioxide, which is a greenhouse gas that contributes to climate change

    coal + oxygen carbon dioxide + energy


    Endothermic reactions
    Endothermic Reactions equations and vice versa for chemical reactions that occur in living and non living systems

    • Endothermic reaction – chemical reaction that absorbs energy

    • For example, in a cold pack, it contains chemicals that absorb energy directly from the environment. When you squeeze the package, you break a container inside the pack that keeps the chemicals separate from each other. When they mix and react, they absorb energy and the whole mixture cools down


    Biochemical reactions
    Biochemical Reactions equations and vice versa for chemical reactions that occur in living and non living systems

    • Two examples of chemical reactions important to life on Earth are photosynthesis and respiration. These two biochemical reactions (may be endothermic or exothermic) form the basis of life as almost all food produced on Earth begins with photosynthesis.


    Characteristics of chemical reactions
    Characteristics of Chemical Reactions equations and vice versa for chemical reactions that occur in living and non living systems

    • Recall: All chemical reactions have these characteristics

      • All reactions involve the production of new substances with their own characteristics (state at room temperature, melting point, colour and density)

      • All reactions involve the flow of energy. This may be detected by a change in temperature during the reaction. Endothermic reactions absorb energy and exothermic reactions release energy.


    Characteristics of chemical reactions1
    Characteristics of Chemical Reactions equations and vice versa for chemical reactions that occur in living and non living systems

    • When new substances form in chemical reactions, sometimes changes of state can be observed. For example, the formation of a gas (bubbles) or a solid (precipitate)

    • All chemical reactions are consistent with the law of conservation of mass

      Any ideas as to what this means?


    Conservation of mass
    Conservation of Mass equations and vice versa for chemical reactions that occur in living and non living systems

    • In 1789, a French chemist, Antoine Lavoisier, came to a very important conclusion. Before we discuss this, try to explain this;

      • Suppose 23.0g of magnesium metal is burned in pure oxygen. When all of the white powder is carefully collected and placed on a scale, its mass is 39.0g. How can it weigh 16g more??

        How does this make sense??


    Conservation of mass1
    Conservation of Mass equations and vice versa for chemical reactions that occur in living and non living systems

    • First, let’s look at Lavoisier’s work. He stated that: when a system of chemicals reacts completely, the total mass of all of the reactants equals the total mass of the products. In other words, in chemical processes, the most important property to be conserved is the number of atoms of each kind that are present. Unlike nuclear processes, chemical reactions do not create or destroy atoms, or change one kind of atom into another. They only reshuffle the atoms that were originally present into different molecular combinations. What we would like to be able to do is to count each kind of atom before and after a reaction and make sure that none has been gained or lost.


    Still how can you start with 23g and end up with 39g
    Still...how can you start with 23g and end up with 39g?? equations and vice versa for chemical reactions that occur in living and non living systems


    Conservation of mass2
    Conservation of Mass equations and vice versa for chemical reactions that occur in living and non living systems

    • Is Lavoisier’s conclusion wrong??

    • No, it’s not wrong, it’s actually telling us that 16g of oxygen reacted with the 23g of magnesium metal. The difference in mass means that there is a reactant that we can’t see – some new form of matter. The difference of mass between the magnesium and white powder product also gives us the mass of this unseen compound.

    • His conclusion is called the law of conservation of mass


    A3 2 writing chemical equations

    A3.2: Writing Chemical Equations equations and vice versa for chemical reactions that occur in living and non living systems

    Unit A: chemistry


    In this section you will learn about1
    In this section you will learn about... equations and vice versa for chemical reactions that occur in living and non living systems

    • General Outcome #3 – Identify and classify chemical changes, and write word and balanced chemical equations for significant chemical reactions, as applications of Lavoisier’s law for conservation of mass

      • ROCK – translate word equations to balanced chemical equations and vice versa for chemical reactions that occur in living and non living systems


    Writing chemical equations
    Writing Chemical Equations equations and vice versa for chemical reactions that occur in living and non living systems

    • Chemical change involves chemical reactions. To record what occurs in a chemical reaction, chemists use a balanced chemical equation made up of chemical formulas.


    Symbolizing chemical change
    Symbolizing Chemical Change equations and vice versa for chemical reactions that occur in living and non living systems

    • To write a chemical equation, you need to know what substances react (the reactants) and what new substances form (the products). This requires you to;

      • careful observations

      • knowledge of what substances are present at the start of the reaction

      • the ability to analyze the materials produced by the reaction


    Symbolizing chemical change1
    Symbolizing Chemical Change equations and vice versa for chemical reactions that occur in living and non living systems

    • Recall: chemical change is often accompanied by visible events such as;

      • change in color

      • production of gas (bubbles)

      • release of heat (increased temperature)

      • appearance of a substance that is only slightly soluble (cloudiness)


    Writing word equations
    Writing Word Equations equations and vice versa for chemical reactions that occur in living and non living systems

    • Consider the chemical reaction between a piece of magnesium metal with hydrochloric acid. We can describe the reaction with the following sentence;

      • solid magnesium metal reacts with aqueous hydrochloric acid to produce aqueous magnesium chloride and hydrogen gas.

        • Which are the products? Which are the reactants?


    Writing word equations1
    Writing Word Equations equations and vice versa for chemical reactions that occur in living and non living systems

    • The word equation for this reaction is;

      magnesium + hydrochloric acid

      magnesium chloride + hydrogen gas

    • The “+” sign groups the reactants and the arrow separates the reactants from the products (which is read “produces”), then the products are separated by a “+” sign as well


    Writing word equations2
    Writing Word Equations equations and vice versa for chemical reactions that occur in living and non living systems

    • Another example;

      • An iron nail is placed in a solution of copper (II) chloride

        iron + copper (II) chloride iron (II) chloride + copper

        Don’t worry about not knowing the products of a chemical reaction, we’ll go through those more in depth later!


    Writing balanced formula equations
    Writing Balanced Formula Equations equations and vice versa for chemical reactions that occur in living and non living systems

    • Formula equation – a chemical equation that uses the reactants and products in a chemical reaction

    • Because mass is conserved in a chemical reaction, you need to write a balanced formula equation (a formula equation that has the same number of atoms of each element in both the reactants and products)


    Writing balanced formula equations1
    Writing Balanced Formula Equations equations and vice versa for chemical reactions that occur in living and non living systems

    • Let’s look at the formula for water;

      hydrogen + oxygen water

      H2 (g) + O2 (g) H2O(l)

      This is called a skeleton equation because it identifies the substances involved in the reaction but it is not balanced.


    Writing balanced formula equations2
    Writing Balanced Formula Equations equations and vice versa for chemical reactions that occur in living and non living systems

    • How do you know the correct proportions?

      • Recall: the law of conservation of mass – the mass of the reactants must equal the mass of the products

        H2 (g) + O2 (g) H2O(l)

    • Follow these steps:

      • Count the number of oxygen and balance

        H2 (g) + O2 (g) → 2 H2O(l)

      • Count the number of hydrogen and balance

        2 H2 (g) + O2 (g) → 2 H2O(l)


    Writing balanced formula equations3
    Writing Balanced Formula Equations equations and vice versa for chemical reactions that occur in living and non living systems

    • Try the following

      N2 (g) + H2(g) → NH3(g)

      • Count the number of nitrogen and balance

        N2 (g) + H2(g) → 2NH3(g)

      • Count the number of hydrogen and balance

        N2 (g) + 3H2(g) → 2NH3(g)


    Writing balanced formula equations4
    Writing Balanced Formula Equations equations and vice versa for chemical reactions that occur in living and non living systems

    • There is no specific element to try to balance first, if you’re having trouble with one element and it won’t seem to balance then start with one of the other elements first!


    Writing balanced formula equations5
    Writing Balanced Formula Equations equations and vice versa for chemical reactions that occur in living and non living systems

    • Try to balance the following:

      • O2 (g) + CH4(g) → CO2(g) + H2O(g)

        • 2O2 (g) + CH4(g) → CO2(g) + 2H2O(g)

      • Fe(NO3)2(aq) + Na3PO4(aq) → NaNO3(aq) + Fe3(PO4)2(s)

        • 3Fe(NO3)2(aq) + 2Na3PO4(aq) → 6NaNO3(aq) + Fe3(PO4)2(s)


    A3 3 five common types of chemical reactions

    A3.3: Five Common Types of Chemical Reactions equations and vice versa for chemical reactions that occur in living and non living systems

    Unit A: Chemistry


    In this section you will learn about2
    In this section, you will learn about... equations and vice versa for chemical reactions that occur in living and non living systems

    • General Outcome #3 – Identify and classify chemical changes, and write word and balanced chemical equations for significant chemical reactions, as applications of Lavoisier’s law for conservation of mass

      • ROCK – classify and identify categories of chemical reactions (formation, decomposition, hydrocarbon combustion, single replacement, double replacement)

      • ROCK – predict the products of formation (synthesis) and decomposition, single and double replacement and hydrocarbon combustion chemical reactions, when given the reactants


    Five common types of chemical reactions
    Five Common Types of Chemical Reactions equations and vice versa for chemical reactions that occur in living and non living systems

    • Chemists have looked at many different types of reactions and found some common characteristics. From the vast array of reactions, a few types have emerged and have also allowed us to predict the outcome of many chemical reactions by examining the reactants.

    • The five common types of chemical reactions are formation, decomposition, hydrocarbon combustion, single replacement and double replacement


    Formation reactions
    Formation Reactions equations and vice versa for chemical reactions that occur in living and non living systems

    • Formation reaction – two elements combine to form a compound (also known as composition or synthesis)

      • element + element = compound

        OR

      • A + B = AB


    Formation reactions1
    Formation Reactions equations and vice versa for chemical reactions that occur in living and non living systems

    • Example:

      • Word Equation:

        • sulfur + oxygen sulfur dioxide

      • Skeleton Equation:

        • S8(s) + O2(g) SO2(g)

      • Balanced Equation:

        • 1S8(s) + 8O2(g)8SO2(g)


    Formation reactions2
    Formation Reactions equations and vice versa for chemical reactions that occur in living and non living systems

    • On your own, try

      • Write the skeleton equation and balanced equation for the following

        • formation of lithium oxide from its elements.

        • formation of lead (IV) bromide from its elements.

        • formation magnesium oxide

        • Formation of iron (III) chloride


    Formation reactions3
    Formation Reactions equations and vice versa for chemical reactions that occur in living and non living systems

    • Skeleton Equation:

      • Li(s) + O2(g) Li2O(s)

    • Balanced Equation:

      • 4Li(s) + 1O2(g)2Li2O(s)

    • Skeleton Equation:

      • Pb(s)+ Br2(l)PbBr4(s)

    • Balanced Equation:

      • Pb(s) + 2Br2(l) PbBr4(s)


    Formation reactions4
    Formation Reactions equations and vice versa for chemical reactions that occur in living and non living systems

    • Skeleton Equation:

      • Mg(s) + O2(g)MgO(s)

    • Balanced Equation:

      • 2Mg(s) + 1O2(g)2MgO(s)

    • Skeleton Equation:

      • Fe(s) + Cl2(g) FeCl3(s)

    • Balanced Equation:

      • 2Fe(s) + 3Cl2(g)2FeCl3(s)


    Decomposition reactions
    Decomposition Reactions equations and vice versa for chemical reactions that occur in living and non living systems

    • Decomposition reaction – products that can be broken down into its reactants

      • compound = element + element

        OR

      • AB = A + B


    Decomposition reactions1
    Decomposition Reactions equations and vice versa for chemical reactions that occur in living and non living systems

    • Example:

      • Word Equation:

        • aluminum chloride aluminum + chlorine

      • Skeleton Equation:

        • AlCl3(s) Al(s) + Cl2(g)

      • Balanced Equation:

        • 2AlCl3(s) 2Al(s) + 3Cl2(g)


    Decomposition reactions2
    Decomposition Reactions equations and vice versa for chemical reactions that occur in living and non living systems

    • On your own, try

      • Write the balanced equation for the following

        • solid magnesium sulfide produces solid magnesium and solid sulfur

        • solid potassium iodide produces solid potassium and solid iodine

        • solid aluminum oxide produces solid aluminum and oxygen gas

        • solid nickel (II) chloride produces solid nickel and chlorine gas


    Decomposition reactions3
    Decomposition Reactions equations and vice versa for chemical reactions that occur in living and non living systems

    • Balanced Equation:

      • 8 MgS(s) 8 Mg(s) + S8(s)

    • Balanced Equation:

      • 2 KI(s) 2 K(s) + I2(s)

    • Balanced Equation:

      • 2 Al2O3(s) 4 Al(s) + 3 O2(g)

    • Balanced Equation:

      • NiCI2(s) Ni(s) + Cl2(g)


    Hydrocarbon combustion reactions
    Hydrocarbon Combustion Reactions equations and vice versa for chemical reactions that occur in living and non living systems

    • Hydrocarbon Combustion reaction – substances that contain hydrogen and carbon

      • CxHy + O2(g) CO2(g) + H2O(g)

        OR

      • hydrocarbon + oxygen produces carbon dioxide + water


    Hydrocarbon combustion reactions1
    Hydrocarbon Combustion Reactions equations and vice versa for chemical reactions that occur in living and non living systems

    • Example:

      • Word Equation:

        • methane + oxygen carbon dioxide + water

      • Skeleton Equation:

        • CH4(g) + O2(g) CO2(g) + H2O(g)

      • Balanced Equation:

        • CH4(g) + 2 O2(g) CO2(g) + 2 H2O(g)


    Hydrocarbon combustion reactions2
    Hydrocarbon Combustion Reactions equations and vice versa for chemical reactions that occur in living and non living systems

    • On your own,

      • Complete and balance each equation

        • C2H6(g) + O2(g)

        • C3H8(g) + O2(g)

        • C 6 H14(g) + O2(g)

        • C6H6(l) + O2(g)


    Hydrocarbon combustion reactions3
    Hydrocarbon Combustion Reactions equations and vice versa for chemical reactions that occur in living and non living systems

    • On your own,

      • Complete and balance each equation

        • 2 C2H6(g) + 7 O2(g) 4 CO2(g) + 6 H2O (g)

        • C3H8(g) + 5 O2(g) 3 CO2(g) + 4 H2O (g)

        • 2 C6H14(l) + 19 O2(g) 12 CO2(g) + 14 H2O(g)

        • 2 C6H6(l) + 15 O2(g) 12 CO2(g) + 6 H2O (g)


    Single replacement reactions
    Single Replacement Reactions equations and vice versa for chemical reactions that occur in living and non living systems

    • Single Replacement reaction – a reactive element reacts with an ionic compound, after the reaction the element ends up in a compound and one of the elements in the reactant ends up as an element

      • A + BC = AC + B


    Single replacement reactions1
    Single Replacement Reactions equations and vice versa for chemical reactions that occur in living and non living systems

    • Example:

      • Word Equation:

        • magnesium + silver nitrate silver + magnesium nitrate

      • Skeleton Equation:

        • Mg(s) + AgNO3(aq) Ag(s) + Mg(NO3)2 (aq)

      • Balanced Equation:

        • Mg(s) + 2 AgNO3(aq) 2 Ag(s) + Mg(NO3)2(aq)


    Single replacement reactions2
    Single Replacement Reactions equations and vice versa for chemical reactions that occur in living and non living systems

    • On your own, try

      • Write the balanced equation for the following

        • aluminum is added to copper (II) chloride, which produces copper and aluminum chloride

        • bromine is mixed with iron (III) iodide to produce iodine and iron (III) bromide

        • chlorine gas is added to a solution of aqueous nickel (III) bromide and the mixture is stirred; it produces aqueous nickel (III) chloride and liquid bromine

        • zinc metal is placed into a solution of silver nitrate and allowed to sit. This produces aqueous zinc nitrate and solid silver metal


    Single replacement reactions3
    Single Replacement Reactions equations and vice versa for chemical reactions that occur in living and non living systems

    • Balanced Equation:

      • 2 Al(s) + 3 CuCl2(aq) 3 Cu(s) + 2 AlCl3(aq)

    • Balanced Equation:

      • 3 Br2(s) + 2 FeI3(aq) 3 I2(s) + 2 FeBr3(aq)

    • Balanced Equation:

      • 3 Cl2(g) + 2 NiBr3(aq) 3 Br2(s) + 2 NiCl3(aq)

    • Balanced Equation:

      • Zn(s) + 2 AgNO3(aq) 2 Ag(s) + Zn(NO3)2(aq)


    Double replacement reactions
    Double Replacement Reactions equations and vice versa for chemical reactions that occur in living and non living systems

    • Double Replacement reaction – the ions in the first compound join with ions in the second compound

      • AB + CD = AD + BC


    Double replacement reactions1
    Double Replacement Reactions equations and vice versa for chemical reactions that occur in living and non living systems

    • Example:

      • Word Equation:

        • lead (II) nitrate + sodium iodide lead (II) iodide + sodium nitrate

      • Skeleton Equation:

        • Pb(NO3)2(aq) + NaI(aq) NaNO3(aq) + PbI2(aq)

      • Balanced Equation:

        • Pb(NO3)2(aq) + 2 NaI(aq) 2 NaNO3(aq) + PbI2(aq)


    Double replacement reactions2
    Double Replacement Reactions equations and vice versa for chemical reactions that occur in living and non living systems

    • On your own, try

      • Write the balanced equation for the following

        • when aqueous copper (I) nitrate and aqueous magnesium bromide are mixed, a precipitate of solid copper (I) bromide forms along with aqueous magnesium nitrate

        • when aqueous aluminum chloride and aqueous sodium hydroxide are mixed, a precipitate of solid aluminum hydroxide forms as well as aqueous sodium chloride


    Double replacement reactions3
    Double Replacement Reactions equations and vice versa for chemical reactions that occur in living and non living systems

    • Balanced Equation:

      • 2 CuNO3(aq) + MgBr2 (aq) Mg(NO3)2(aq) + 2 CuBr(s)

  • Balanced Equation:

    • 3 NaOH(aq) + AlCI3(aq) Al(OH)3(s) + 3 NaCl(aq)


  • A3 4 the mole

    A3.4: The Mole equations and vice versa for chemical reactions that occur in living and non living systems

    Unit A: Chemistry


    In this section you will learn about3
    In this section, you will learn about... equations and vice versa for chemical reactions that occur in living and non living systems

    • General Outcome #3 – Identify and classify chemical changes, and write word and balanced chemical equations for significant chemical reactions, as applications of Lavoisier’s law for conservation of mass

      • ROCK – interpret balanced chemical equations in terms of moles of chemical species and relate the mole concept to the law of conservation of mass

      • SAND – define the mole as the amount of an element containing 6.02 X 1023 atoms (Avogadro’s number) and apply the concept to calculate quantifies of substances of other chemical species


    Did you know1
    Did you know?? equations and vice versa for chemical reactions that occur in living and non living systems

    • Mole day is celebrated on October 23 each year. It begins at 6:02 am and ends at 6:02 pm. The numbers are associated with these dates and times derived from Avogadro’s number, a constant known to all chemists in the world. It’s value is approximately 6.02 X 1023


    The mole
    The Mole equations and vice versa for chemical reactions that occur in living and non living systems

    • Chemists deal with atoms and molecules all the time, and they need to measure quantities of matter precisely. Balanced equations indicated the correct proportion of atoms and molecules to use in a reaction.

    • Since atoms and molecules are very small, the quantity used to measure them needs to be a very large number.


    Molar mass
    Molar Mass equations and vice versa for chemical reactions that occur in living and non living systems

    • Molar mass – the mass of one mole of a substance

    • Experiments have been done to determine the atomic molar mass (found on the periodic table), you can use the atomic molar mass to find the molar mass of any substance


    Avogadro s number and the mole
    Avogadro’s Number and the Mole equations and vice versa for chemical reactions that occur in living and non living systems

    • Mole – the quantity that chemists use to measure elements and compounds (symbol: mol)

    • The number of particles in 1 mol is called Avogadro’s number (6.02X1023)

    • To define the mole, chemists chose to work with an isotope of the element carbon-12. Carbon is a stable solid, so it is easy to work with. You will learn more about this in Chemistry 20!!


    Molar mass of metals
    Molar Mass of Metals equations and vice versa for chemical reactions that occur in living and non living systems

    • What is the molar mass of the following metals? Give the symbol and then write the molar mass.

      • Calcium – Ca, 40.08 g/mol

      • Lithium – Li, 6.94 g/mol

      • Copper – Cu, 63.55 g/mol

      • Silver – Ag, 107.87 g/mol

      • Tungsten – W, 183.84 g/mol


    Molar mass of polyatomic elements
    Molar Mass of Polyatomic Elements equations and vice versa for chemical reactions that occur in living and non living systems

    • What is the molar mass of the following polyatomic elements? Give the symbol and then write the molar mass.

      • Oxygen – O2, 32.00 g/mol

      • Fluorine - F2, 38.00 g/mol

      • Hydrogen – H2, 2.02 g/mol

      • Sulfur – S8, 256.56 g/mol

      • Phosphorus – P4, 123.88 g/mol


    Molar mass1
    Molar Mass equations and vice versa for chemical reactions that occur in living and non living systems

    • What is the molar mass of methane?

      • formula: CH4 (g) – contains one carbon atom and four hydrogen atoms

      • H = 1.01 g/mol X 4 = 4.04 g/mol

      • C = 12.01 g/mol X 1 = 12.01 g/mol

      • Add them together to get 16.05 g/mol

        Therefore the molar mass for one molecule of methane is 16.05 g/mol.


    Molar mass2
    Molar Mass equations and vice versa for chemical reactions that occur in living and non living systems

    • Find the molar mass of the following compounds

      • MgO

      • Li2S

      • Ga2Se3

      • CaCO3

      • Cr3(PO3)2

      • C8H18


    Molar mass3
    Molar Mass equations and vice versa for chemical reactions that occur in living and non living systems

    • Find the molar mass of the following compounds

      • MgO - 40.31 g/mol

      • Li2S – 45.95 g/mol

      • Ga2Se3 – 376.32 g/mol

      • CaCO3 – 100.09 g/mol

      • Cr3(PO3)2 – 313.94 g/mol

      • C8H18 – 114.26 g/mol


    Molar mass4
    Molar Mass equations and vice versa for chemical reactions that occur in living and non living systems

    • Find the molar mass of the following compounds

      • Strontium chloride

      • Potassium phosphide

      • Manganese (II) nitride

      • Aluminum chromate

      • Glucose

      • Cobalt (III) sulfite


    Molar mass5
    Molar Mass equations and vice versa for chemical reactions that occur in living and non living systems

    • Find the molar mass of the following compounds

      • Strontium chloride – SrCl2 – 158.52 g/mol

      • Potassium phosphide – K3P – 148.28 g/mol

      • Manganese (II) nitride – Mn3N2–192.84g/mol

      • Aluminum chromate – Al2(CrO4)3 – 401.96 g/mol

      • Glucose – C12H22O11 – 342.34 g/mol

      • Cobalt (III) sulfite – Co2(SO3)3 – 358.07g/mol


    Molar mass6
    Molar Mass equations and vice versa for chemical reactions that occur in living and non living systems

    • In other words, to find mass:

      m = n X M

      where

      m is the quantity of matter in grams (g)

      n is the quantity of matter in moles (mol)

      M is the molar mass (g/mol)


    The factor label method of converting between quantities
    The Factor-Label Method of Converting between Quantities equations and vice versa for chemical reactions that occur in living and non living systems

    • This is used for converting between the number of moles of a substance and its mass.

      • Because 1 mol C = 12.01g C their ratio has a value of 1

      • 12.01g C = 1 The fraction is called a “factor”

        1 mol C and the units are called “labels”

      • To find 3.000 moles of carbon: Since this is a moles-to-mass conversion, we choose the factor that has “mole” in the denominator so it will cancel out the “mol” in 3.000 mol.

      • mc= 3.00 mol X 12.01g

        1 mol


    The factor label method of converting between quantities1
    The Factor-Label Method of Converting between Quantities equations and vice versa for chemical reactions that occur in living and non living systems

    • mc= 3.00 mol X 12.01g = 36.03 g C

      1 mol

      Try the following

      • How many moles of silicon are in a 56.18 g sample?

        • n = m = 56.18g = 2.000 mol

          M 28.090 g/mol

      • What is the mass of 10.0 mol of water?

        • m = n X M

          m = 10.0 mol X 18.02 g/mol

          m = 180 g of water


    The mole concepts and the law of conservation of mass
    The Mole Concepts and the Law of Conservation of Mass equations and vice versa for chemical reactions that occur in living and non living systems

    • Recall: the law of conservation of mass states that, in any reaction, the total mass of the reactants equals the total mass of the products.

    • When chemists read equations that have been balanced, they often read the coefficients as moles. One reason is that you can see a mole of something, while it is impossible to see an atom of something. Another reason is that chemists use the mole to measure out chemicals.


    The mole concepts and the law of conservation of mass1
    The Mole Concepts and the Law of Conservation of Mass equations and vice versa for chemical reactions that occur in living and non living systems

    • For example, consider the reaction of sodium metal with oxygen gas

      word: sodium + oxygen sodium oxide

      balanced: 4 Na(s) + O2(g) 2Na2O(s)

      you can read it as:

      4 atoms Na(s) + 1 molecule O2(g) 2 molecules Na2O(s)

      it can also be read as:

      4 moles Na(s) + 1 mole O2(g) 2 moles Na2O(s)


    Did you know2
    Did you know?? equations and vice versa for chemical reactions that occur in living and non living systems

    If you had Avogadro’s number of toonies, or 1 mol of toonies, they would cover all of Canada to a height of about 60 km and all of Earth to a height of about 1 km.


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