SolutionsSolutions- TEK I9D- TEK I9Ddemonstrate how various demonstrate how various factors influence solubility factors influence solubility

including temperature, including temperature, pressure, and nature of the pressure, and nature of the

solute and solventsolute and solvent

A solution is a type of mixture that is A solution is a type of mixture that is homogeneous throughout. homogeneous throughout.

Day 3: #1

Types of SolutionsTypes of Solutions

Saturated Saturated – a solution which cannot hold – a solution which cannot hold any more soluteany more solute

UnsaturatedUnsaturated – a solution in which more – a solution in which more solute can be added and which will still solute can be added and which will still dissolvedissolve

Day 3: #1

Parts of a Solution Parts of a Solution

SoluteSolute-the part that gets dissolved-the part that gets dissolved

SolventSolvent-the part that does the dissolving-the part that does the dissolving

Day 3: #1

How can you increase the How can you increase the dissolving rate of a solid solute in a dissolving rate of a solid solute in a

liquid solvent?liquid solvent?

Increase the surface area of the solute (Increase the surface area of the solute ( ie, ie, grinding, crushing)grinding, crushing)

stir or shake the solutionstir or shake the solution

heat the solutionheat the solution

Day 3: #1

Solubility - is the maximum amount of Solubility - is the maximum amount of a solute that can be dissolved in a a solute that can be dissolved in a given amount of solvent at a given given amount of solvent at a given

temperature.temperature. Increasing Temperature - will increase the Increasing Temperature - will increase the

solubility of a solid solute in a liquid solventsolubility of a solid solute in a liquid solventExample: dissolving sugar in hot tea VS cold Example: dissolving sugar in hot tea VS cold

tea tea

Increasing Pressure – will increase the Increasing Pressure – will increase the solubility of a gas solute in a liquid solventsolubility of a gas solute in a liquid solvent

Example: carbonated beverages are bottled Example: carbonated beverages are bottled “under pressure” to increase the amount of “under pressure” to increase the amount of carbon dioxide gas in a cokecarbon dioxide gas in a coke

  1. 1. Which of the following salts has the greatest Which of the following salts has the greatest solubility in water at 25°C?solubility in water at 25°C?

  

(F) CaCO(F) CaCO33 (G) FeS(G) FeS (H) HgCl (H) HgCl22 (J) KClO(J) KClO44

Solubility Rules Solubility Rules 1. All sodium, potassium, and ammonium salts 1. All sodium, potassium, and ammonium salts are soluble.are soluble.2. All silver, lead, and mercury salts are insoluble.2. All silver, lead, and mercury salts are insoluble.3. All carbonates, sulfides, and hydroxides are 3. All carbonates, sulfides, and hydroxides are insoluble.insoluble.4. All sulfates are soluble except calcium sulfate 4. All sulfates are soluble except calcium sulfate and barium sulfate.and barium sulfate.

2. A 0.2 g crystal of gypsum dissolves very 2. A 0.2 g crystal of gypsum dissolves very slowly in 100 mL of water while the water is slowly in 100 mL of water while the water is stirred.stirred.

Which of these would cause the gypsum toWhich of these would cause the gypsum to

dissolve faster?dissolve faster?

  

F F Decreasing the water temperatureDecreasing the water temperature

G G Stopping the stirringStopping the stirring

H H Lowering the air pressureLowering the air pressure

J J Crushing the crystal Crushing the crystal

Question from TEA released TAKS test

3. All of these can affect the rate at which 3. All of these can affect the rate at which a solid dissolves in water except —a solid dissolves in water except —

  

AA decreasing air pressure decreasing air pressure

B B stirring the waterstirring the water

C C increasing the temperature of the waterincreasing the temperature of the water

D D using larger crystals of the solidusing larger crystals of the solid

Question from TEA released TAKS test

4. Over time an open soft drink will lose4. Over time an open soft drink will lose

carbonation (dissolved COcarbonation (dissolved CO22). Which of these). Which of these

allows the COallows the CO22 to remain in solution the to remain in solution the

longest?longest?

  

A A Reduced air pressureReduced air pressure

B B Exposure to direct sunlightExposure to direct sunlight

C C Increased air currentsIncreased air currents

DD Cooler temperatures Cooler temperatures

Question from TEA released TAKS test

5. As a scuba diver goes deeper underwater, 5. As a scuba diver goes deeper underwater, the diver must be aware that the increased the diver must be aware that the increased pressure affects the human body by pressure affects the human body by increasing the –increasing the –

(A) body’s temperature(A) body’s temperature

(B) amount of dissolved gases in the body(B) amount of dissolved gases in the body

(C) amount of suspended solids in the body(C) amount of suspended solids in the body

(D) concentration of minerals in the body(D) concentration of minerals in the body

Question from TEA released TAKS test