Solutions

Solution Definitions Soluble - capable of being____________ 2. Solution – _______________mixtures 3. Saturated - ________________________ amount of dissolved solute that can be dissolved into the solution 4. Unsaturated -_________solute than saturated 5. Supersaturated -__________ dissolved solute than saturated

Parts of a Solution Solute-the part that gets dissolved (less) Solvent-the part that does the dissolving (more)

When 4 g of Kool-Aid is mixed with 100 g of water, what is the solute When 4 g of Kool-Aid is mixed with 100 g of water, what is the solute? ____________ What is the solvent? ____________ 4 g of Kool-Aid 100 g of water

Factors Affecting Solubility 1. Types of solvents and solutes a. “_____________ dissolves _______________” A polar solvent, such as water, will dissolve polar and ionic solutes. Nonpolar solvents, such as oils, will dissolve other nonpolar solutes. 2. Pressure a. Liquids and solids - little to no effect b. Gases - solubility increases with increased pressure Henry’s law - solubility of a gas in a liquid is ___________ proportional to the partial pressure of that gas on the surface of the liquid 3. Temperature Liquids and solids - increase temperature ___________ solubility (mostly) b. Gases - increase temperature _______________ solubility

Factors Affecting Rates of Dissolving 1. Surface area - _____________________ 2. Agitation - __________________is faster 3. Heat a. Liquids and solids - increase in heat mostly ______________ rate of dissolving b. Gases - increase in heat _________ rate 4. Pressure a. Liquids - ____________________ b. Gases - increase pressure ______________________________rate

Some solutions conduct electricity, some don’t Electrolytes – compounds that conduct an electric current in an aqueous solution OR in the molten state. An electrolyte solution contains charged particles (______), which can move. Any salt (ionic compound – metal + nonmetal) dissolved in water is an electrolyte: NaCl, KI, etc. Demo: Use a conductivity tester instead to demo salt water vs. sugar water (conductivity testers are found in the main storage room)

Which solution contains ions (electrolytes)?

Types of Electrolytes ____________________– a large portion of the solute exists as ions, such as aqueous solutions of all ionic compounds ____________________– these are solutions in which only a small portion of the solute exists as ions ____________________- compounds that do NOT conduct electricity in either aqueous solution of melted distilled water gases molecular (covalent) compounds (2 nonmetals) organic compounds – alcohols, sugars, etc. anything containing a ______________. Demo: you might want to use a demo to explain these concepts….the intensity of the light bulb will tell you if it’s a strong/weak electrolyte or if it doesn’t light up, then it’s a a nonelectrolyte

Which solution contains electrolytes?_____ Which solution will conduct electricity?_____ NaCl NaCl Solution A Solution B

S O L U B I T Y R U L E S Explain to your students how to read the solubility table on their periodic tables

Solubility Rules I DO: Nitrate reacts with sodium.

Solubility Rules NaNO3 I DO: Nitrate reacts with sodium. Predict compound: Na+1 NO3-1 NaNO3

Solubility Rules I DO: Nitrate reacts with sodium. Predict compound: Na+1 NO3-1 NaNO3 2) Use Solubility Chart 3) Conclusion: NaNO3 is soluble (dissolve) no precipitate: NaNO3(aq)

AgCl WE DO: 1. Chlorine (Cl-1) reacts with silver (Ag+1). Is the compound formed soluble or insoluble?________________Will a precipitate be formed? _______________ Remember charges must cancel out: Ag is +1 and Cl is -1 AgCl is insoluble so it needs to be written as AgCl(s) because it forms a precipitate insoluble Yes AgCl(s)

Group 1 YOU DO: 2. Carbonate (CO3-2) reacts with sodium (Na+1). Will a precipitate be formed?_________________ You need two Na because charges must cancel out. No Na+ CO32- Na2CO3

Net Ionic Equations A net ionic equation is a chemical equation for a reaction which lists only those compounds or elements participating in the reaction. Rules: Steps: Balance the equation and label compounds (solid, liquid, gas, aqueous). Break the aqueous compounds apart. Cancel any elements that are identical on both sides. Write the remaining elements = net ionic equation. Double-check that the net ionic equation is balanced.

I Do: A solution of NaI is combined with a solution of Pb(NO3)2 to produce PbI2 and NaNO3. a. Label the compounds from the balanced equation (aq) for aqueous or (s) for solid b. Cross out the element or polyatomic ion that forms the aqueous part of the solution. c. Write a net ionic equation for this reaction: Pb(NO3)2 (aq) 2NaI (aq)  PbI2 (s) + 2NaNO3 (aq) + Pb(NO3)2 + 2NaI  PbI2 NaNO3 (aq) (s) 2 2 I-1 (aq) PbI2 (s)

c. Write a net ionic equation for this reaction: You Do: sodium chloride + lead (II) sulfate produces sodium sulfate + lead (II) chloride . a. Label the compounds from the balanced equation (aq) for aqueous or (s) for solid: b. Cross out the element or polyatomic ion that forms the aqueous part of the solution. c. Write a net ionic equation for this reaction: 2 NaCl + PbSO4  2 NaSO4 PbCl2 (aq) (s) 2 NaCl + PbSO4  2 NaSO4 PbCl2 (aq) (s) 2 Cl -1 (aq) PbCl2 (s)

Solubility Table

a) 50 g KCl in 100 g of water at 90°C. ____ Homework #4: Based on the solubility chart below, decide whether each of the following is U: unsaturated, S: saturated, SS: supersaturated, or N: not enough information is given. a) 50 g KCl in 100 g of water at 90°C. ____ b) 50 g KCl in 100 g of water at 60°C. ____ c) 70 g KNO3 in 100 g of water at 70°C. ____ d) 50 g KNO3 in 50 g of water at 60°C. ____ U SS For problem d, use ratios to find out how to figure out how many grams of KNO3 you need tp use in 100g of water: Xg KNO3/100g H2O = 50 g KNO3/50 g H2O U S

6. Circle the correct type for the following solutions: Homework #6: 6. Circle the correct type for the following solutions: NaCl (aq): electrolyte or nonelectrolyte b) CCl4 (l): electrolyte or nonelectrolyte