Exam 1

Question 1

What is the best explanation for why electrolyte solutions conduct electricity?

Answer 1

the presence of free-flowing ions

Question 2

When potassium chromate, K2CrO4, is dissolved in water, what ions are produced?

Answer 2

2 K+ + CrO4-

Question 3

Arrange these from least soluble to most soluble

H20
C3H8
C2H5OH

Answer 3

H2O, C2H5OH, C3H8

Question 4

Identify the solute and solvent:
table sugar, water

Answer 4

table sugar = solute
water = solvent

Question 5

Identify the solute and solvent:
air (a solution of 78% N2, 21% O2, and various other gases)

Answer 5

N2 = solvent
O2 = solute

Question 6

Identify the solute and solvent:
A solution of 33% ethanol and 67% water

Answer 6

water = solvent
ethanol = solute

Question 7

Identify the solute and solvent:
bronze (an alloy of 95% copper and 5% tin)

Answer 7

copper = solvent
tin = solute

Question 8

Identify the solute and solvent:
CO2 in water

Answer 8

CO2 = solute
water = solvent

Question 9

Molality

Answer 9

mol solute / kg solvent

Question 10

Molarity

Answer 10

mol solute / liters solution

Question 11

Strong electrolytes are ____ ________

Answer 11

completely ionized

Question 12

Determine whether an aqueous solution of each compound will conduct electricity
(NH4)2SO4
Ca(OH)2
C6H12O6
C2H4O

Answer 12

Conducts electricity: (NH4)2SO4, Ca(OH)2
Does not conduct electricity: C6H12O6, C2H4O

Question 13

Classify the substances as electrolytes and non electrolytes
K2CO3
CCl4
NaOH
MgCl2
C6H12O6

Answer 13

Electrolytes: K2CO3, NaOH, MgCl2
Non Electrolytes: CCl4, C6H12O6

Question 14

Classify each compound as strong electrolytes, weak electrolytes, and non electrolytes
HBr
NaOH
CaCl2
CH3COOH
CH3NH2
CH3OH
C6H12O6

Answer 14

Strong Electrolytes: HBr, NaOH, CaCl2
Weak Electrolytes: CH3COOH,CH3NH2
Non Electrolytes: CH3OH, C6H12O6

Question 15

Complete the equation for the disassociation of the electrolyte KOH(aq). Omit water from the equation because it is understood to be present.

Answer 15

KOH- (aq) -> K+ (aq) + OH- (aq)

Question 16

Classify the compounds as acids or bases in aqueous solution
CH3COOH
HBr
H2CO3
HCN
NaOH
Mg(OH)2

Answer 16

Acids: CH3COOH, HBr, H2CO3, HCN
Bases: NaOH, Mg(OH)2

Question 17

Classify each of these substances as an electrolyte or a non-electrolyte
a soluble ionic compound
sodium chloride, NaCl
potassium iodide, KI
sodium hydroxide, NaOH
most molecular solutes
table sugar
methanol, CH3OH
a substance that forms an aqueous solution which does not conduct electricity

Answer 17

Electrolyte: a soluble ionic compound, sodium chloride, NaCl, potassium iodide, KI, sodium hydroxide, NaOH
Non electrolyte: most molecular solutes, table sugar, methanol, CH3OH, a substance that forms an aqueous solution which does not conduct electricity

Question 18

How does the concentration of a gas in solution change when the partial pressure of the gas above the solution increases?

Answer 18

The concentration of the gas in solution increases

Question 19

Henry’s Law

Answer 19

The quantity of an ideal gas that dissolves in a definite volume of a liquid is directly proportional to the pressure of the gas

Question 20

Alloy

Answer 20

A solid mixture of two or more metals

Question 21

Colloid

Answer 21

The general term for heterogeneous mixture that appears to be homogeneous to the naked eye

Question 22

Emulsion

Answer 22

The specific term of a heterogeneous mixture of two liquids that appears to be homogeneous to the naked eye

Question 23

Emulsifying Agent

Answer 23

A substance that allows two liquids to mix more fully because it is soluble in both of them

Question 24

Mass percent

Answer 24

mass solute / mass solution * 100

Question 25

Raoult's Law

Answer 25

The partial pressure exerted by any component of an ideal solution is equal to the vapor pressure of that component multiplied by its mole fraction in the solution

Question 26

Dalton's Law

Answer 26

Total pressure of a gaseous mixture equals the sum of partial pressures of all the components of the mixture