SOLUTIONS and SOLUBILITY. Know for test. 1. Definition mixture solution solute solvent solubility dilute concentrated.
MIXTURE: Two or more substances existing together that can be separated by physical means such as filtration or raising or lowering the temperature. The substances do not form chemical bonds.
SOLUTE: A substance that is dissolved in another substance.SOLVENT: A substance that dissolves another substance.The compound in the largest percentage is the solvent
SOLUBILITY:Amount of solute that can dissolve in a solvent at a given temperature, or the maximum amount of grams of a solute that will dissolve in 100 mL of solvent at a certain temperature.
CONCENTRATION: Comparative amounts of solute in a solventDILUTE:Small amount of solute in the solventCONCENTRATED:Large amount of solute in the solventWe’ll consider anything greater than a 6 molar (6M) solution as concentrated
1. Is a 5 molar solution of sulfuric acid dilute or concentrated?
2. Name for maximum amount of solute that will dissolve in 100 mL of solvent at a given temperature.
3. Is a solution a heterogeneous or homogeneous mixture?
Rate of dissolution
3. In a solution pick the solute and
solvent based on ratios
ELECTROLYTE: A substance that separates into ions or forms ions in a water solution and allows electricity to flow through the solution. Examples: NaCl - separates into ions; HCl - forms ions
NONELECTROLYTE: A substance that does not separate into or form ions in a water solution and does not allow electricity to flow through the solution.
A. Is it a solvent or a solute?1. The substance present in the higher percentage is the solvent.2. The substance present in the lower percentage is the solute.
4. In a solution made of 78% nitrogen, 21% oxygen, .09% argon, and .01% other gases which is the solvent?
5. Sulfuric acid is a polar covalent molecule that when placed in water breaks apart into positive and negative charges, is this process called dissociation or ionization?
6. When sodium chloride is placed in water electricity can be conducted, is this dissociation or ionization?
4. Conditions for dissolving
5. Know alloys
6. Factors affecting rate of dissolving
1. Ionic compounds dissolve only ionic compounds.2. Nonpolar solvents will dissolve only nonpolar solutes - kerosene dissolves grease.
a. Other polar covalent compounds like sugar or HClb. Ionic compounds like salt (NaCl) c. The hydrogen and oxygen dipoles in water are attracted to the positive and negative charges of the ions in the ionic compound.
b. Alcohols are both polar and nonpolar. Ethanol will combine with iodine (I2 is nonpolar) on the nonpolar end and water on the polar end.
c. Soaps and detergents remove oil because the nonpolar molecule ends combine with oils and the polar molecule ends combine with water to pull the oils into solution.
3. Smaller particles mean increased surface area of solute covered by the solvent, causing the solute to dissociate into ions or the molecules of solute to ionize more quickly.
100, 1 x 1 CUBES
1. Stirring lemonade causes the sugar to dissolve faster and the lemon juice to disperse more quickly.2. Water erodes rock more quickly at waterfalls, rapids, and eddies.
c. Many nuclear power plants release warm water and have caused a change in the flora and fauna that are found downstream of their outlet pipes.Fish and plant life now found in these streams are usually found in streams much further south.
7. Name three methods that will increase the rate of solubility.
8. Name for a solution of copper, tin, and silver.
9. Which of the following will increase the solubility of a gas in a liquid?
Increased surface area, increased pressure, increased temperature, stirring
A. The solubility of a compound refers to the maximum number of grams of a substance that will dissolve in 100 grams of solvent at a certain temperature.
GRAMS per 100 GRAMS OF WATER
at DIFFERENT TEMPERATURES
10. On the following graph how many grams of Potassium chloride will dissolve in 100 mL of water at 40 degrees Celsius?
11. On the following chart what temperature is required to dissolve 150g of silver nitrate in 100mL of water?
5. Saturation values for water solutions are expressed as grams per 100 mL or 100 grams of water.Water has a mass of 1 gram per 1 mL of volume; the measurement system was set up this way.
2. More solute can be dissolved in the solvent at the specified temperature.3. No undissolved solute is visible in the container.
5. Unsaturated is an imprecise term – the amount of solute can be anything less than the saturated amount for the specified temperature.
2. No more solute can be dissolved in the solvent at the specified temperature.3. Undissolved solute is still visible in the container.
3. Supersaturated solutions are obtained by:a. Raising the temperature of a saturated solvent until the solute dissolves completely
b. Cooling the solution to the specified temperature.c. The solute will remain in solution if allowed to cool slowly and not shaken or disturbed in any way.
4. A supersaturated solution is unstable and crystals will form ifa. The solution is agitated(shaken or stirred)b. The solution contacts other crystals
12. On the following chart what is the saturation state of a solution containing 80g of KBr at 30° Celcius?
B. Precise concentrations are expressed in percentages.C. Concentration of a solid dissolved in a liquid is expressed as percentage by mass
13. Use the following chart to determine how many grams of KBr would be required to saturate a solution in 300 mL of water at 70 degrees Celcius
Examples:1. Juice drinks are usually 10% juice and 90% water. If there is 100 mL of drink in a box, how much of the drink is juice and how much is water?
14. How many milliliters of isopropyl alcohol are in 300 mL of a 70% solution?
2. Dissociation is due toa. The negative partial charge of the oxygen atom in the water molecule attracting the positive ion in the compound.
c. The force of attraction between the partial charges of the water molecules and the ionic particles in the compound is strong enough to break the bonds holding the ionic compound together.
15. Sulfuric acid is a polar covalent molecule that breaks into a hydrogen cation and sulfate anion when placed in water. Is this process called dissociation or ionization?
16. NaCl separates into a sodium cation and chlorine anion when placed in water. Is this process called dissociation or ionization?
A. Pure water does not conduct electricity – nonelectrolyteB. Some particles in solution cause water to conduct electricity because they form electrolytes.
1. Both dissociation and ionization cause the water to conduct electricity because of the formation of ions that are called electrolytes in a solution.
1. This interference lowers the temperature required to freeze the solvent for example: antifreeze or salt added to water lower the freezing point of water.
a. The solute interferes with the evaporation of the solventb. More energy is needed to allow the solvent to evaporatec. Example: antifreeze or salt raises the boiling point of water
3. The size of the changes in the freezing and boiling points depends on the amount of solute in the solvent (concentration)**number of particles determine size of changes
1. Freezing point depression
2. Boiling point elevation
3. Vapor pressure lowering
17. Name three colligative properties