Solutions ch 13-14 p. 394 Solution: one substance dissolved into another substance 3 types: gas….. liquid… solid…. 2 parts: solute = substance being dissolved……’smaller part’ solvent = substance doing the dissolving …’larger part’ Ex: salt water carbonated pepsi Kool-aid lemonade Heterogeneous = a visible mixture of 2 or more Homogenous = one kind

Why are GASES ARE MORE SOLUBLE IN COOLER SOLVENTS How to speed up dissolving? l. Stir 2. Increase surface area…. grind large chunks into small grains 3. change temperature of solvent a. increase temp…..sugar in tea b. Decrease temp…..gas in pepsi Why are GASES ARE MORE SOLUBLE IN COOLER SOLVENTS

How do the methods of speeding the rate of solution for dissolving a solid in a liquid compare to the methods of dissolving a gas in a liquid?

Determining what will dissolve? How do things dissolve? Water is considered the universal solvent… water is a polar molecule with + and – ends. The positive end of a polar molecule will attract the negative end of another polar molecular. Hence…. ” like dissolves like”. “polar dissolves polar” “Nonpolar dissolves nonpolar”

“like dissolves like” explains why Polar means having opposite ends, which means one end of the molecule is positive and the other end is negative. “like dissolves like” explains why salt dissolves in water (both are polar) any ionic (m+nm) will dissolve in water Like dissolves like explains why salt does not dissolve in ethanol one is polar the other is nonpolar “water and oil” --- polar and non polar --- doesn’t mix Overhead 73

How does one figure if polar or non polar ???? 1. all ionics are polar …. Metal + nonmetal 2. draw lewis structures 3. calculate electronegativity 1.7

Solute Water CCl4 NaCl I2 - Br2 - KNO3 - Ca(OH)2 - CF4 - HCl H2SO4 - Cu2SO4 - Fe(NO3)

Electrolyte: a solution that can conduct electricity ex: ionic solutions ionic compounds … ionizes into their separate ions when dissolved in water. “They separate into their + and - parts.”) Non electrolyte: a solution that can not conduct electricity ex: nonpolar solutions non-metals and non-metals do not have + or - ends Demo: salt in water

Solute electrolyte non- NaCl I2 - Br2 - KNO3 - Ca(OH)2 - CF4 - HCl H2SO4 - Cu2SO4 - Fe(NO3)

how much will dissolve at a given temperature. Solubility how much will dissolve at a given temperature. Unsaturated: can dissolve more solute Saturated: dissolved all it can Supersaturated: contains more solute than a saturated . ”unstable” Reading solubility curve….ws 13.22 , 13.12

[M] = #moles of solute liters of solution [concentration] of Solutions p.412 Expressed as …..Molarity [M] = #moles of solute liters of solution As a chemist you need to solve the following solutions for an experiment. What is the molarity of a solution consisting of 45 grams of Sodium Chloride in 500mL of water? 2. A chemist needs half a liter of a [2M] solution of ammonia. How do you prepare it?

Calculate the concentration of a sodium hydroxide solution containing 10.0 grams in 500mL. What is the molarity of a sulfuric acid solution containing 196 grams per liter?

Quick Lab Prepare 100mL of a .5M Sodium Hydroxide solution. Label with you name and store upright in bottom drawer.

Molarity by Dilution M1V1 = M2V2 You use this when you already have a solution made and you just want to dilute it to the concentration you want. 1. How much concentrated 12M Hydrochloric acid is needed to prepare 300 mL of a 3.0 M solution?

How much water should be added to 200mL of 18M Sulfuric acid to have a l.5M solution?

3. How much of concentrated 15M Nitric acid should be added to make a 1 liter solution of 2M.

4. To how much water should 50 4. To how much water should 50.mL of 12 M hydrochloric acid be added to produce a 4.0 M solution? Flip side of ws.

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