Why is it harmful to pee in the pool? Simba the cat and Kendra the dog would really like to know!

Properties of solutions Chapter 16.1 Learning Objectives: Identify the factors that affect how fast a substance dissolves Describe the equilibrium in a saturated solution Describe the factors affecting the solubility of a substance

In your notes explain: Granulated sugar dissolves faster than sugar cubes when placed in tea. Both granulated sugar and sugar cubes dissolve faster when you stir ice tea or place them in hot tea instead. Why is this?

Factors that affect how fast a substance dissolves Agitation Temperature Particle size of the solute

Agitation If solvent is stirred, the solute dissolves more quickly. Fresh solvent(water) is continuously brought into contact with the solutes(sugar) surface. Only affects the rate of a solid solute dissolving

Temperature Solutes dissolve faster in higher temperatures Kinetic energy=solvent molecules moving faster Faster motion of solvent particles = increase of force of collisions between solvent and solute surface.

Particle size of the solute Smaller particles expose a greater surface area to solvent molecules Ex: small particles in sugar show more surface area to the colliding water molecules surface area exposed=faster rate of dissolving

What will not speed up the rate at which a solid solute dissolves? Increasing the temperature Stirring the mixture Crushing the solute Decreasing the temperature

What you think is happening in the figure? Particles move from solid into the solution Some dissolved particles move from the solution back to the solid Processes occur at the same rate= no overall change in the system

Saturated Solutions are @ equilibrium Solution is saturated Saturated solution is the max amount of solute for an amount of solvent (@ constant temp. and pressure)

Solubility Amount of solute that dissolves in a certain amount of solvent @ a specified temperature and pressure Produces a saturated solution Expressed as grams of solute 100 g of solvent

Unsaturated Solution contains less solute than a saturated solution @ a certain temp. and pressure If more solute is added, solute will dissolve until solution is saturated Unsaturated Solution Saturated Solution

Two liquids are miscible if dissolved in each other in ALL proportions/quantities Two liquids are immiscible if they are insoluble in each other

Solubility affected by: Temperature- solubility increases as the temperature of the solvent increases (in most cases)

Solubilities of Substances in Water at Various Temperatures Interpret Data Solubilities of Substances in Water at Various Temperatures Solubility (g/100 g H2O) Substance Formula 0°C 20°C 50°C 100°C Barium hydroxide Ba(OH)2 1.67 31.89 — Barium sulfate BaSO4 0.00019 0.00025 0.00034 Calcium hydroxide Ca(OH)2 0.189 0.173 0.07 Potassium chlorate KClO3 4.0 7.4 19.3 56.0 Potassium chloride KCl 27.6 34.0 42.6 57.6 Sodium chloride NaCl 35.7 36.0 37.0 39.2 Sodium nitrate NaNO3 74 88.0 114.0 182 Aluminum chloride AlCl3 30.84 31.03 31.60 33.32 Silver nitrate AgNO3 122 222.0 455.0 733 Sucrose (table sugar) C12H22O11 179 230.9 260.4 487 Hydrogen H2 0.00016 0.00013 0.0 Oxygen O2 0.0070 0.0043 0.0026 Carbon dioxide CO2 0.335 0.169 0.076 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.

Solubility affected by: Supersaturated solution has more solute than it theoretically holds @ a certain temperature

Crystallization of supersaturated solutions can be initiated by a small crystal, called a seed crystal of solute is added. The solution is clear before a seed crystal is added. Crystals begin to form immediately after the addition of a seed crystal. Excess solute crystallizes rapidly.

Solubility is affect by: 2. Pressure- strongly influences solubility of gases (little effect on solid and liquid solubility)

Opening the bottle partial pressure of CO2 decreases Carbonated drinks are under high pressure of CO2 gas, pushing a large amount of gas into the water. Opening the bottle partial pressure of CO2 decreases CO2 gas immediately escapes from the liquid

Henry’s Law At any given temperature, Solubility (S) of a gas in a liquid is related to the pressure (P) above the liquid = S1 P1 S2 P2 S P

If the solubility of a gas in water is 0. 77 g/L at 3 If the solubility of a gas in water is 0.77 g/L at 3.5 atm, what is the solubility (in g/L) at 1.0 atm? Temperature is held constant.

Solubility curves

What doe the graphs mean? Each line shows how much solute can be dissolved in 100 mL of H2O (solvent) @ different temperatures. Why at different temps? Hotter water is better at dissolving solute. Hot water dissolves a solute faster, but it can also dissolve A GREATER MASS OF SOLUTE, in the same amount of water.

Each solubility curve represents SATURATED SOLUTIONS at a given temperature Solubility above the curve means solution is SUPERSATURATAED Solubility below the curve means solution is UNSATURATED

What happens to the solubility of KNO3 as the temperature increases? What substance shows least change in solubility as temperature increases? If NaCl was added to a saturated solution of NaCl at 20°C and warmed to the mixture of 40°C. What happens to the added NaCl?