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Chemical Reactions. 2/3- 2/4. Signs of a chemical reaction?. Indicators of chemical reactions. Emission of energy. Formation of a gas. Formation of a precipitate. Color change. What is a chemical reaction composed of? . Contains reactants and products

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indicators of chemical reactions
Indicators of chemical reactions
  • Emission of energy
  • Formation of a gas
  • Formation of a precipitate
  • Colorchange
what is a chemical reaction composed of
What is a chemical reaction composed of?
  • Contains reactants and products
  • Formulas must be written correctly with symbols and subscripts

3) Law of conservation of matter requires that coefficients be used to ensure that atoms

describing chemical reaction
Describing chemical reaction
  • The way atoms are joined is changed
  • Atoms aren’t created or destroyed.
  • May involve a catalyst
  • Can be described several ways

In a sentence

  • Solid Copper reacts with chlorine gas to form aqueous copper (II) chloride.

In a word equation or formula equation

  • Copper(s) + chlorine(g) ®copper(II) chloride(aq)
  • Cu(s) + Cl2(g)® CuCl2(aq)
reaction energy
Reaction Energy
  • All chemical reactions are accompanied by a change in energy. 
  • Exothermic - reactions that release energy to their surroundings (usually in the form of heat)
    • ΔH (enthalpy) is negative – energy leaving system
  • Endothermic - reactions that need to absorb heat from their surroundings to proceed.
    • ΔH (enthalpy) is positive – energy coming into the system
reaction energy1
Reaction Energy
  • Spontaneous Reactions - Reactions that proceed immediately when two substances are mixed together.  Not all reactions proceed spontaneously.
  • Some require…
  • Activation Energy – the amount of energy that is required to start a chemical reaction.
    • Once activation energy is reached the reaction continues until you run out of material to react.  
what is a catalyst
What is a catalyst?
  • Does not cause a reaction to occur, but speeds up the rate which a reaction occurs
  • Can be in the form of the following:
    • Energy- light, heat
    • Chemicals
    • Enzymes are biological or protein catalysts.
word equations
Word Equations
  • Word Equations: an equation in which the reactants and products in a chemical reaction are represented by words instead of chemical formulas.
  • The problem with word equations is they do not actually show the number of atoms or molecules of each substance… formulas would have to be written out for this to happen.

(Absent? We looked at examples of these in class)

formula equations
Formula Equations
  • Represents reactants and products of a chemical reaction by their symbols or formulas.
  • Unbalanced- does not account for law of conservation of matter
  • Balanced- using coefficients show the representative numbers
  • See table 2 on page 266 for important symbols
word formula practice
Word Formula practice

Fe(s) + O2(g)® Fe2O3(s)

Solid iron reacts with oxygen gas to form solid iron III oxide (rust).

formula equation
Formula Equation

Nitric acid dissolved in water reacts with solid sodium carbonate to form liquid water and carbon dioxide gas and sodium nitrate dissolved in water.

HNO3(aq) + Na2CO3 (s)® NaNO3(aq) + H2O(l)

convert this to a formula equation
Convert this to a formulaequation

Solid iron (III) sulfide reacts with gaseous hydrogen chloride to form iron (II) chloride and hydrogen sulfide gas.

Fe2S3(s) + HCl(g)®FeCl2 (s) + H2S(g)

slide17

A silver spoon tarnishes. The solid silver reacts with sulfur in the air to make solid silver sulfide, the black material we call tarnish and water.

Ag (s) + H2S (g) + O2(g)® Ag2S (s) + H2O

in class work
In-class work
  • In-class we practiced writing word and formula equations for different chemical reactions.
  • See chemical reactions sheet
balancing equations
Balancing Equations

___ H2(g) + ___ O2(g) ---> ___ H2O(l)

2

2

  • What Happened to the Other Oxygen Atom?
  • This equation is not balanced! Until…
ch 4 2 o 2 co 2 2 h 2 o
CH4 + 2 O2 CO2 + 2 H2O

Reactants Products

1 C atom 1 C atom

4 H atoms 4 H atoms

4 O atoms 4 O atoms

Timberlake, Chemistry 7th Edition, page 167

reactants products
Reactants  Products

+

C(s) + O2(g) CO2(g)

carbon oxygen carbon dioxide

Reactants Product

1 carbon atom 1 carbon atom

2 oxygen atoms 2 oxygen atoms

catalyst – speeds up reaction

+

Pt

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

hydrogen oxygen water

2

2

Pt

Reactants

4 hydrogen atoms 4 hydrogen atoms

2 oxygen atoms 2 oxygen atoms

Reactants Product

2 hydrogen atoms 2 hydrogen atoms

2 oxygen atoms 1 oxygen atoms

Reactants Product

2 hydrogen atoms 4 hydrogen atoms

2 oxygen atoms 2 oxygen atoms

Un

balanced

Timberlake, Chemistry 7th Edition, page 164

slide22

Cl

H

H

H

Cl

Cl

Cl

H

reactants products

reactants products

H

H

Cl

Cl

Unbalanced and Balanced Equations

H

Cl

Cl

Cl

H

H

H2 + Cl2 2 HCl

(balanced)

(unbalanced)

H2 + Cl2 HCl

2

1

2

2

1

2

2

2

types of reactions
Types of Reactions
  • There are millions of reactions
  • Objectives:
    • We will learn 6 types.
    • We will be able to predict the products.
    • We will be able to predict whether they will happen at all.
synthesis reactions
Synthesis Reactions
  • Also called combination reactions
  • 2 elements, or compounds combine to make one compound.
  • A + B ® AB
  • Na (s) + Cl2 (g)® NaCl (s)
  • Ca (s) +O2 (g)® CaO (s)
  • SO3 (s) + H2O (l)® H2SO4 (s)
  • We can predict the products if they are two elements.
  • Mg (s) + N2 (g)®

Mg3N2(s)

synthesis reaction
Synthesis Reaction

Direct combination reaction (Synthesis)

2 Na + Cl2 2 NaCl

Cl

Na

Na

Cl

Cl

Cl

Na

Na

General form: A + B  AB

element or element or compound

compound compound

synthesis reaction1
Synthesis Reaction

Direct combination reaction (Synthesis)

2 Mg + O2 2 MgO

Mg

Mg2+

O2-

O

O2-

O

Mg

Mg2+

General form: A + B  AB

element or element or compound

compound compound

decomposition reactions
Decomposition Reactions
  • decompose = fall apart
  • one compound (reactant) falls apart into two or more elements or compounds.
  • Usually requires energy
  • AB ® A + B
  • NaCl Na + Cl2
  • CaCO3 CaO + CO2
decomposition reactions1
Decomposition Reactions
  • Can predict the products if it is a binary compound
  • Made up of only two elements
  • Falls apart into its elements
  • H2O
  • HgO

H2(g) + O2(g)

Hg (s) + O2(g)

decomposition reactions2
Decomposition Reactions
  • If the compound has more than two elements you must be given one of the products
  • The other product will be from the missing pieces
  • NiCO3(aq)
  • H2CO3(aq)®

CO2(g)

+ Ni (s)

H2(g)

+ CO2(g)

decomposition reaction

H

H

H

H

Decomposition Reaction

Decomposition reaction

2 H2O

+

2 H2

O2

H

O

O

H

+

H

O

O

H

General form: AB

A

+

B

compound

two or more elements

or compounds

single replacement
Single Replacement
  • single displacement
  • One element replaces another
  • Reactants= an element and a compound.
  • Products= a different element and a different compound.
  • A + BC ® AC + B
  • Based on the activity series (in other words the element replacing must be more active.
activity series

Element Reactivity

Activity Series

Li

Rb

K

Ba

Ca

Na

Mg

Al

Mn

Zn

Cr

Fe

Ni

Sn

Pb

H2

Cu

Hg

Ag

Pt

Au

Halogen Reactivity

F2

Cl2

Br2

I2

Foiled again –

Aluminum loses to Copper

double replacement
Double Replacement
  • Two things replace each other.
  • Reactants must be two ionic compounds or acids.
  • Usually in aqueous solution

AB+ CD ®AD + CB

ZnS + 2HCl ®

ZnCl + H2S

AgNO3 + NaCl ®

AgCl+ NaNO3

formation of a solid agcl
Formation of a solid AgCl

AgNO3(aq) + KCl(aq)  KNO3 (aq) + AgCl(s)

single and double replacement reactions
Single and Double Replacement Reactions

Single-replacement reaction

Mg + CuSO4 MgSO4 + Cu

General form:

A + BC  AC + B

Double-replacement reaction

CaCO3 + 2 HCl  CaCl2 + H2CO3

General form:

AB + CD  AD + CB

combustion
Combustion
  • A reaction in which a compound (often carbon) reacts with oxygen
  • CH4 + O2 ®CO2 + H2O
  • C3H8 + O2® CO2 + H2O
  • C6H12O6 + O2® CO2 + H2O
slide40
The charcoal used in a grill is basically carbon. The carbon reacts with oxygen to yield carbon dioxide. The chemical equation for this reaction is C + O2 CO2
exploding flour
Exploding Flour

FLOUR

EXPLOSION:

Fuel (flour)

Ignition (candle)

Oxygen (combustion)

6” PVC Pipe

As confinement increases,

EXPLOSION is greater.

combustion of a hydrocarbon
Combustion of a Hydrocarbon

GENERAL FORMULA: CH + O2 CO2 + H2O

Many homes get heat from propane (C3H8) heaters.

Write a balanced chemical equation for the complete

combustion of propane gas.

C3H8(g) + O2(g)  CO2(g) + H2O(g)

C3H8(g) + O2(g)  CO2(g) + H2O(g)

5

3

4

+ energy

combustion of hydrocarbon cont
Combustion of Hydrocarbon (cont.)

Ideal Stoichiometry

D

C3H8(g) + O2(g)  CO2(g) + H2O(g)

5

3

4

+ energy

Too ‘rich’ (not enough oxygen – too much fuel)

D

3

4

C3H8(g) + O2(g)  3CO(g) + H2O(g)

+ energy

3

4

C3H8(g) + O2(g)  C (g) + H2O(g)

2

+ energy

SOOT

combustion of methane gas
Combustion of Methane Gas

Davis, Metcalfe, Williams, Castka, Modern Chemistry, 1999, page 245

combustion of methane gas1

+

+

=

Combustion of Methane Gas

One methane

molecule

Two oxygen

molecules

One carbon

dioxide molecule

Two water

molecules

CH4

2 O2

CO2

2H2O

1 carbon

+

4 hydrogen

1 carbon

+

2oxygen

2 oxygen

+

4hydrogen

4oxygen

Davis, Metcalfe, Williams, Castka, Modern Chemistry, 1999, page 245

combustion of glucose
Combustion of Glucose

Kelter, Carr, Scott, Chemistry A World of Choices 1999, page 130

combustion of iron
Combustion of Iron
  • Formation of Rust
  • Thermite Reaction
      • underwater welding
      • Temp. = ~3500oC

4 Fe+O2 2 Fe2O3

Fe2O3 + 2 Al  2 Fe + Al2O3 + 199 kcal

combustion of copper
Combustion of Copper
  • Copper burns with a green color
  • Copper forms a patina (oxide)
    • green in color
      • CuO2
    • black in color
      • CuO

Statue of Liberty is covered with

copper that has oxidized to form

copper (II) oxide, CuO2.

acid base reaction
Acid/Base Reaction
  • An acid and a base react to form a salt and water.
  • Always in aqueous solution
  • Acid (H+) + Base (OH-) →Salt + H2O
  • NaOH + HCl → NaCl + H2O
  • NH4OH + H2SO4 → (NH4)2SO4 + H2O
how to recognize which type

Redox

How to recognize which type
  • Look at the reactants
      • Element(E), Compound(C)
  • E + E
  • C
  • E + C
  • C + C
  • Acid + Base
  • Look at the Products
  • CO2 + H2O

Synthesis

Decomposition

Single replacement

Double replacement

Acid/Base reaction

Combustion

examples
Examples

Synthesis

  • H2 + O2®

Decomposition

  • H2O ®

Double replacement

  • AgNO3 + NaCl ®
  • Zn + H2SO4®

Single replacement

  • HgO ®

Decomposition

  • KBr +Cl2®

Single replacement

  • Mg(OH)2 + H2SO3®

Double replacement

examples1
Examples

Acid/Base

  • HNO3 + KOH ®

Decomposition

  • CaPO4®

Single replacement

  • AgBr + Cl2®
  • Zn + O2®

Synthesis

  • HgO + Pb®

Single replacement

  • HBr + NH4OH ®

Acid/Base

  • Cu(OH)2 + KClO3®

Double replacement

summary
Summary

An equation:

  • Describes a reaction
  • Must be balanced because to follow Law of Conservation of Energy
  • Can only be balanced by changing the coefficients.
  • Has special symbols to indicate state, and if catalyst or energy is required.
  • Can describe 5 different types of reactions.
stoichiometry is
Stoichiometry is…
  • Greek for “measuring elements”

Pronounced “stoy kee ahm uh tree”

  • Defined as: calculations of the quantities in chemical reactions, based on a balanced equation.
  • There are 4 ways to interpret a balanced chemical equation
1 in terms of particles
#1. In terms of Particles
  • An Element is made of atoms
  • A Molecular compound (made of only nonmetals) is made up of molecules(Don’t forget the diatomic elements)
  • Ionic Compounds (made of a metal and nonmetal parts) are made of formula units
example 2h 2 o 2 2h 2 o
Example: 2H2 + O2→2H2O
  • Two molecules of hydrogen and one molecule of oxygen form two molecules of water.
  • Another example: 2Al2O3® 4Al+3O2

2

formula units

Al2O3

form

4

atoms

Al

and

3

molecules

O2

Now read this: 2Na + 2H2O ® 2NaOH + H2

2 in terms of moles
#2. In terms of Moles
  • The coefficients tell us how many moles of each substance

2Al2O3® 4Al+3O2

2Na + 2H2O ® 2NaOH + H2

  • A balanced equation is a Molar Ratio- We will look at this next.
3 in terms of mass
#3. In terms of Mass
  • The Law of Conservation of Mass applies
  • We can check mass by using moles.

2H2 + O2®2H2O

2.02 g H2

2 moles H2

4.04 g H2

=

1 mole H2

+

32.00 g O2

1 mole O2

32.00 g O2

=

1 mole O2

36.04 g H2 + O2

36.04 g H2 + O2

reactants

in terms of mass for products
In terms of Mass (for products)

2H2 + O2®2H2O

18.02 g H2O

36.04 g H2O

=

2 moles H2O

1 mole H2O

36.04 g H2 + O2

36.04 g H2O

=

36.04 grams reactant = 36.04 grams product

The mass of the reactants must equal the mass of the products.

4 in terms of volume
#4. In terms of Volume
  • At STP, 1 mol of any gas = 22.4 L

2H2+ O2®2H2O

(2 x 22.4 L H2) + (1 x 22.4 L O2) ® (2 x 22.4 L H2O)

NOTE: mass and atoms are ALWAYS conserved - however, molecules, formula units, moles, and volumes will not necessarily be conserved!

67.2 Liters of reactant ≠44.8 Liters of product!

mole ratios
Mole Ratios
  • Ratio between two of the substances in a balanced equation
  • Derived from coefficients of any two substances in an equation.
writing mole factors
Writing Mole Factors

4 Fe + 3 O2 2 Fe2O3

Fe and O2

4 mol Fe and 3 mol O2

3 mol O2 4 mol Fe

Fe and Fe2O3

4 mol Fe and 2 mol Fe2O3

2 mol Fe2O3 4 mol Fe

slide64
O2 and Fe2O3

3 mol O2 and 2 mol Fe2O3

2 mol Fe2O3 3 mol O2

learning check
Learning Check

3 H2(g) + N2(g) 2 NH3(g)

A. A mol factor for H2 and N2 is

1) 3 mol N22) 1 mol N2 3) 1 mol N2

1 mol H2 3 mol H2 2 mol H2

B. A mol factor for NH3 and H2 is

1) 1 mol H2 2) 2 mol NH3 3) 3 mol N2

2 mol NH3 3 mol H2 2 mol NH3

answers
Answers:

3 H2(g) + N2(g) 2 NH3(g)

A. A mol factor for H2 and N2 is

2) 1 mol N2

3 mol H2

B. A mol factor for NH3 and H2 is

2) 2 mol NH3

3 mol H2

converting moles
Converting Moles

2Al2O3® 4Al+3O2

  • each time we use 2 moles of Al2O3 we will also make 3 moles of O2

2 moles Al2O3

3 mole O2

or

3 mole O2

2 moles Al2O3

Molar ratios can also be known as conversion factors. We could use them to solve calculations.

example
Example:
  • How many moles of O2 are produced when 3.34 moles of Al2O3 decompose?

2Al2O3® 4Al+3O2

3 mol O2

5.01 mol O2

3.34 mol Al2O3

=

2 mol Al2O3

Conversion factor from balanced equation

If you know the amount of ANY chemical in the reaction, you can find the amount of ALL the other chemicals!

practice
Practice:

4 Fe + 3 O22 Fe2O3

How many moles of Fe2O3 are produced when 6.0 moles O2 react?

6.0mol O2 x mol Fe2O3 = 4.0 mol Fe2O3

mol O2

more practice
More Practice:

4 Fe + 3 O2 2 Fe2O3

How many moles of Fe are needed to react with 12.0 mol of O2?

1) 3.00 mol Fe

2) 9.00 mol Fe

3) 16.0 mol Fe

answer
Answer:

4 Fe + 3 O2 2 Fe2O3

12.0 mol O2 x mol Fe = 16.0 mol Fe

mol O2

4

3

more practice1
More Practice

4 Fe + 3 O2 2 Fe2O3

How many grams of O2 are needed to produce 0.400 mol of Fe2O3?

1) 38.4 g O2

2) 19.2 g O2

3) 1.90 g O2

answer1
Answer:

0.400 mol Fe2O3 x 3 mol O2 x 32.0 g O2

2 mol Fe2O3 1 mol O2

= 19.2 g O2

converting mass
Converting Mass
  • Balance equation
  • Convert starting amount to moles
  • Use coefficients to write a mol-mol factor
  • Convert moles of desired to grams
example1
Example:

The reaction between H2 and O2 produces 13.1 g of water. How many grams of O2 reacted?

Write the equation

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

Balance the equation

2 H2 (g) + O2 (g) 2 H2O (g)

slide76
Organize data

2 H2 (g) + O2 (g) 2 H2O (g)

? g 13.1 g

Plan g H2O molH2O molO2O2

Setup

13.1 g H2O x 1 mol H2O x 1 mol O2 x 32.0 g O2 8.0 g H2O 2 mol H2O 1 mol O2

= 11.6 g O2

points to remember
Points to Remember

1. Read an equation in moles

2. Convert given amount to moles

3. Use mole factor to give desired moles

4. Convert moles to grams

grams (given grams (desired)

moles (given) moles (desired)

mass mass problem
Mass-Mass Problem:

6.50 grams of aluminum reacts with an excess of oxygen. How many grams of aluminum oxide are formed?

4Al + 3O2 2Al2O3

6.50 g Al

1 mol Al

2 mol Al2O3

101.96 g Al2O3

=

? g Al2O3

4 mol Al

1 mol Al2O3

26.98 g Al

12.3 g Al2O3

are formed

(6.50 x 1 x 2 x 101.96) ÷ (26.98 x 4 x 1) =

another example
Another example:
  • If 10.1 g of Fe are added to a solution of Copper (II) Sulfate, how many grams of solid copper would form?

2Fe + 3CuSO4® Fe2(SO4)3 + 3Cu

Answer = 17.2 g Cu

practice1
Practice

How many O2 molecules will react with 505 grams of Na to form Na2O?

4 Na + O2 2 Na2O

Complete the set up:

505 g Na x 1 mol Na x ________ x _______

23.0 g Na

answer2
Answer:

4 Na + O2 2 Na2O

505 g Na x 1 mol Na x 1 mol O2 x 6.02 x 1023

23.0 g Na 4 mol Na 1 mol O2

= 3.30 x 1024molelcules

slide82
More Practice:

Acetylene gas C2H2 burns in the oxyactylene torch for welding. How many grams of C2H2 are burned if the reaction produces 75.0 g of CO2?

2 C2H2 + 5 O2 4 CO2 + 2 H2O

75.0 g CO2 x _______ x _______ x _______

answer3
Answer:

2 C2H2 + 5 O2 4 CO2 + 2 H2O

75.0 g CO2 x 1 mol CO2 x 2 mol C2H2 x 26.0 g C2H2

44.0 g CO2 4 mol CO2 1 mol C2H2

= 22.2 g C2H2

volume volume calculations

22.4 L CH4

1 mol O2

1 mol CH4

22.4 L O2

Volume-Volume Calculations:
  • How many liters of CH4 at STP are required to completely react with 17.5 L of O2 ?

CH4 + 2O2® CO2 + 2H2O

1 mol CH4

22.4 L CH4

1 mol O2

17.5 L O2

2 mol O2

1 mol CH4

22.4 L O2

= 8.75 L CH4

Notice anything relating these two steps?

avogadro told us
Avogadro told us:
  • Equal volumes of gas, at the same temperature and pressure contain the same number of particles.
  • Moles are numbers of particles
  • You can treat reactions as if they happen liters at a time, as long as you keep the temperature and pressure the same.

1 mole = 22.4 L @ STP

shortcut for volume volume
Shortcut for Volume-Volume?
  • How many liters of CH4 at STP are required to completely react with 17.5 L of O2?

CH4 + 2O2® CO2 + 2H2O

1 L CH4

17.5 L O2

= 8.75 L CH4

2 L O2

Note: This only works for Volume-Volume problems.

limiting reagants
Limiting Reagants
  • If the amounts of two reactants are given, the reactant used up first determines the amount of product formed.
  • Limiting reagents- the reactant that is used up in a chemical reaction.
  • Excess reagents- the reactant that is left over after chemical reaction.
example2
Example:

Suppose you are preparing cheese sandwiches. Each sandwich requires 2 pieces of bread and 1 slice of cheese. If you have 4 slices of cheese and 10 pieces of bread, how many cheese sandwiches can you make?

cheese sandwich products
Cheese Sandwich Products

Sandwich 1

+ + =

Sandwich 2

+ + =

practice2
Practice:

How many sandwiches can you make?

____ slices of bread

+ ____ slices of cheese

= ____ sandwiches

What is left over? ________________

What is the limiting reactant?

practice3
Practice

How many sandwiches can you make?

__10__ slices of bread

+ __4__ slices of cheese

= __4__sandwiches

What is left over? _2 slices of bread

What is the limiting reactant? cheese

hints for lr problems
Hints for LR Problems

1. For each reactant amount given, calculate the

moles (or grams) of a product it could produce.

2.The reactant that produces the smaller amount of product is the limiting reactant.

3. The number of moles of product produced by the limiting reactant is ALL the product possible. There is no more limiting reactant left.

how do you find out which is limited
How do you find out which is limited?
  • The chemical that makes the least amount of product is the “limiting reagent”.
  • You can recognize limiting reagent problems because they will give you 2 amounts of chemical
  • Do two stoichiometry problems, one for each reagent you are given.
slide95

Cu is the Limiting Reagent, since it produced less product.

  • If 10.6 g of copper reacts with 3.83 g sulfur, how many grams of the product (copper (I) sulfide) will be formed?

2Cu + S ® Cu2S

1 mol Cu2S

1 mol Cu

159.16 g Cu2S

10.6 g Cu

2 mol Cu

63.55g Cu

1 mol Cu2S

= 13.3 g Cu2S

= 13.3 g Cu2S

1 mol Cu2S

1 mol S

159.16 g Cu2S

3.83 g S

1 mol S

32.06g S

1 mol Cu2S

= 19.0 g Cu2S

another example1
Another example:
  • If 10.3 g of aluminum are reacted with 51.7 g of CuSO4 how much copper (grams) will be produced?

2Al + 3CuSO4→ 3Cu + Al2(SO4)3

the CuSO4 is limited, so Cu = 20.6 g

  • How much excess reagent will remain?

Excess = 4.47 grams

percent yield
Percent Yield

You prepared cookie dough to make 5 dozen cookies. The phone rings while a sheet of 12 cookies is baking. You talk too long and the cookies burn. You throw them out (or give them to your dog.) The rest of the cookies are okay.

How many cookies could you have made (theoretical yield)?

How many cookies did you actually make to eat? (Actual yield)

types of yield
Types of Yield:

Actual yield is the amount of product actually recovered from an experiment

Theoretical (possible) yield is the maximum

amount of product that could be produced from

the reactant.

Percent Yield is the actual yield compared to the maximum (theoretical yield) possible.

details on yield
Details on Yield
  • Percent yield tells us how “efficient” a reaction is.
  • Percent yield can not be bigger than 100 %.
  • Theoretical yield will always be larger than actual yield!
    • Why? Due to impure reactants; competing side reactions; loss of product in filtering or transferring between containers; measuring
percent yield calculation
Percent Yield Calculation

What is the percent yield of cookies?

Percent Yield = Actual Yield (g) recovered X 100 Possible Yield (g)

% cookie yield = 48 cookies x 100 = 80% yield

60 cookies

example3
Example:
  • 6.78 g of copper is produced when 3.92 g of Al are reacted with excess copper (II) sulfate.

2Al + 3 CuSO4® Al2(SO4)3 + 3Cu

  • What is the actual yield?
  • What is the theoretical yield?
  • What is the percent yield?

= 6.78 g Cu

= 13.8 g Cu

= 49.1 %