Question

Answer

Explanation

21 Which hydrocarbon is saturated?

(1) propene    (3) butene
(2) ethyne       (4) heptane

4

Saturated = all single bonds

alkanes

22 Which statement correctly describes an endothermic chemical reaction?

(1) The products have higher potential energy than the reactants,
and the ΔH is negative.
(2) The products have higher potential energy than the reactants, and
the ΔH is positive.
(3) The products have lower potential energy than the reactants, and
the ΔH is negative.
(4) The products have lower potential energy than the reactants, and
the ΔH is positive.

2

Endothermic=energy in products have more energy than reactans

ΔH is positive

23 At standard pressure when NaCl is added to water, the solution will
have a

(1) higher freezing point and a lower boiling point than water
(2) higher freezing point and a higher boiling point than water
(3) lower freezing point and a higher boiling point than water
(4) lower freezing point and a lower boiling point than water

3

Boiling point elevation

Freezing point depression

24 Which element has atoms that can form single, double, and triple
covalent bonds with other atoms of the same element?

(1) hydrogen     (3) fluorine
(2) oxygen        (4) carbon

4

Definition of how carbon bonds

25 Which compound is an isomer of pentane?

(1) butane        (3) methyl butane
(2) propane      (4) methyl propane

3

Must have 5 carbons

26 In which substance does chlorine have an oxidation number of +1?

(1) Cl₂       (3) HClO
(2) HCl      (4) HClO₂

3

HClO

H +1

Cl +1

O -2

27 Which statement is true for any electrochemical cell?

(1) Oxidation occurs at the anode, only.
(2) Reduction occurs at the anode, only.
(3) Oxidation occurs at both the anode and the cathode.
(4) Reduction occurs at both the anode and the cathode.

1

An ox red cat

2

Reduction charge goes down and the electrons are on the more + side

29 Which 0.1 M solution contains an electrolyte?

(1) C₆H₁₂O₆ (aq)       (3) CH₃ OH(aq)
(2) CH₃ COOH(aq)    (4) CH₃ OCH₃ (aq)

2

Electrolytes

Acid bases salts

Never CH3OH (not a base but an alcohol)

4

Acid and base makes salt and water