Unit 5 – Solutions, Acids & Bases

rocklin.k12.ca.us

Unit 5 – Solutions, Acids & Bases

Essential Skills Review


5-1. Know the definitions of solute and solvent (CSS: 6a)

5-2. Know how to describe the dissolving process at the

molecular level using the concept of random molecular

motion & how temperature, pressure and surface area

affect the dissolving process. (CSS: 6b, 6c)

5-3. Know that molecules in a liquid move in random

patterns relative to one another because the

intermolecular forces are too weak to hold the molecules

in a solid form. (CSS: 2d)


Making Solutions

• Solution: a mixture of two or more

substances in a single phase

• Solute: the substance that is dissolved into

the solution

• Solvent: the substance that dissolves the

solute

• Factors that Speed Up the Dissolving

Process:

1. Increase in temperature

2. Increase in surface area (grinding up

the substance)

3. Agitation (stirring or shaking)

4. Increase in pressure (this only works

for gases)

• “Like Dissolves Like”

Solute + Solvent = Solution


5-4. Know how to calculate the concentration of a solute in

terms of grams per liter, molarity, parts per million and

percent composition. (CSS: 6d)


Concentration Calculations

• Molarity (M)

• % Composition

M

MolesofSolute

LitersofSolution

GramsofSolute

% Composition

x100

GramsofSolution

• Grams per Liter (g/L)

GramsperLiter

GramsofSolute

LitersofSolution

• Parts per million (ppm)

ppm

• Conversion Factors to know:

• 1 gram H2O = 1 mL H2O

• 1 L = 1000 mL

GramsofSolute 6

x10

GramsofSolution


5-5. Know the observable properties of acids, bases, and

salt solutions; that acids are hydrogen-ion-donating and

bases are hydrogen-ion-accepting substances; (CSS: 5a,

5b)

5-6. Know how to use the pH scale to characterize acid and

base solutions. (CSS: 5d)

5-7. Know that strong acids and bases fully dissociate and

weak acids and bases partially dissociate. (CSS: 5c)


pH Scale

• Reading a pH Scale:

• 0 < 7 = acid

• 7 = neutral

• 7>14 = base

• Strong acids are closer to

pH 0

• Strong bases are closer to

pH 14

• Weak acids & bases are

closer to pH 7


Dissociation of Acids & Bases

Strong Acids or Bases

Weak Acids or Bases

• Almost completely

dissociation in water

• Only partially dissociation in

water


5-8. Know how an acid and a base neutralize each other.


Neutralization

Acids and bases react to form salts (ionic

compounds) and water

• The products of this reaction have a pH ≈ 7 (neutral)

• Acid + Base Salt + H 2 O (neutral substance)

More magazines by this user
Similar magazines