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Unit 3 review

Total questions: 50

Worksheet time: 1hrs 15mins

Name
Class
Date
1.
Consider the following reaction. What would be the equilibrium constant expression?
4Br2(g) + CH4(g) ↔  4HBr(g) + CBr4(g)
a)
[Br2]4  [CH4]/ [HBr]4  [CBr4]
b)
[HBr]4 [CBr4]/ [Br2]4 [CH4]
c)
[HBr ]/ [Br2]4 [CH4]
d)
[HBr]4 [CBr4]/ [Br2]4 [CH]4
2.

In the following reaction


Sn2+ + 2Fe3+ → Sn4+ + 2Fe2+


the oxidizing agent is....

a)

Sn4+

b)

Sn2+

c)

Fe3+

d)

Fe2+

3.

What is a disproportionation reaction?

a)

A reaction in which at least two different oxidation states are produced

b)

A reaction in which elements are reduced and oxidised

c)

A reaction in which at least one element is oxidised

d)

A reaction in which the same element is both oxidised and reduced

4.

BF3, BCl3 and AlCl3 can be described as..........

a)

electron rich

b)

electron deficient

c)

amphoteric

d)

electron acceptors

5.

Which one of the following can reduce concentrated sulfuric acid down to hydrogen sulfide?

a)

Fluoride ions

b)

Chloride ions

c)

Bromide ions

d)

Iodide ions

6.

Nitrogen cannot exhibit covalency more than four due to

a)

presence of vacant d orbitals

b)

presence of vacant p orbitals

c)

due to absence of vacant d orbitals

d)

due to inert pair effect

7.

What is a ligand?

a)

A molecule with empty d-orbitals

b)

A molecule with a lone pair that can form a coordinate bond to a transition metal

c)

A molecule which can form ionic bonds to a central metal atom

d)

A complex which is coloured

8.

Identify which of the following ions are most likely to form coloured compounds

a)

Sc3+

b)

Cu+

c)

Zn2+

d)

Fe3+

9.

What is y?

a)

order of reaction with respect to reactant A

b)

order of reaction with respect to reactant B

c)

overall order of reaction

d)

coefficient of reaction B in a balanced equation

10.

If the unit of the rate is moldm-3 s-1 and the overall order is 2, what is the unit of the rate constant?

a)

s-1

b)

moldm-3 s-1

c)

mol-1dm6 s-1

d)

mol-1dm3 s-1

11.

For a reaction, Rate = k[NO]2[O2]. What happens to the rate when [NO] is doubled?

a)

doubled

b)

halved

c)

tripled

d)

quadrupled

12.

First electron affinity of an element is usually ________ and second electron affinity is ____________.

a)

exothermic, endothermic.

b)

exothermic, exothermic.

c)

endothermic, endothermic.

d)

endothermic, exothermic.

13.

What enthalpy change does the number 4 represent?

a)

Formation

b)

1st ionisation energy of Na

c)

1st electron affinity of Na

d)

Atomisation of Na

14.

Which enthalpy change is NOT required in a Born Haber cycle for aluminium chloride?

a)

2nd ionisation energy of aluminium

b)

2nd electron affinity of chlorine

c)

Lattice enthalpy of aluminium chloride

d)

Enthalpy of formation of aluminium chloride

15.

What factor determines the feasibility of a reaction?

a)

Change in entropy

b)

Change in enthalpy

c)

Both change in entropy and change in enthalpy

d)

None of the above

16.

Which represents a -ΔS?

a)

ice melting

b)

salt dissolving

c)

water heating up

d)

none of these

17.

Choose the correct correlation between Gibbs free energy and feasibility.

a)

a reaction to be feasible, ΔG has to be negative.

b)

a reaction to be feasible, ΔG has to be positive.

c)

a reaction to be feasible, ΔG has to be zero

d)

no correlation between ΔG and feasibility

18.

The following cell has an EMF of +0.46 V.


Cu | Cu2+ || Ag+ | Ag


Which statement is correct about the operation of the cell?

a)

Metallic copper is oxidised by Ag+ ions.

b)

The silver electrode has a negative polarity.

c)

The silver electrode gradually dissolves to form Ag+ ions.

d)

Electrons flow from the silver electrode to the copper electrode via an external circuit.

19.

Use the data in the table to answer this question.


The most powerful oxidising agent in the table is

a)

Mn2+(aq)

b)

Zn(s)

c)

MnO4-(aq)

d)

Zn2+(aq)

20.

What is the formula of this complex?

a)

[Co(H2O)6]2+

b)

[Co(OH)2(H2O)4]2+

c)

[Co(OH)2(H2O)4]

d)

[Co(OH)6]3-

21.

A green precipitate that is unchanged on adding excess NaOH contains

a)

Cr3+

b)

Fe2+

c)

Mn2+

d)

Cu2+

22.

A blue solution produces a blue precipitate with a little ammonia solution. What happens with excess ammonia solution?

a)

No change

b)

The precipitate dissolves to give a yellow solution

c)

The precipitate dissolves to give a purple solution.

d)

The precipitate dissolves to give a deep blue solution.

23.

What is the pH at the equivalence point.

a)

The pH is approximately 5

b)

The pH is approximately 6

c)

The pH is approximately 8

d)

The pH is approximately 9

24.
Acidic buffer is made up of
a)
weak acid and weak base
b)
weak acid and its conjugate salt
c)
weak acid and its conjugate base
d)
strong acid and its conjugate base
25.

What is a buffer compromised of?

(CHECK ALL THAT APPLY)

a)

A weak acid and its conjugate base

b)

A weak base and its conjugate acid

c)

A strong base and its conjugate base

d)

A strong acid and its conjugate acid

26.

Which species will oxidise Fe2+(aq) to Fe3+(aq)?

a)

Br2 (aq)

b)

Cl-(aq)

c)

I2 (aq)

d)

Mn2+(aq)

27.
Which statement is correct about value of Eο?
a)
more positive value Eο, greater driving force for reduction
b)
more negative value Eο, greater driving force for reduction
c)
more positive value Eο, greater the rate of reaction
d)
more negative value Eο, greater the rate of reaction
28.

Which species will oxidise Fe2+(aq) to Fe3+(aq)?

a)

Br2 (aq)

b)

Cl-(aq)

c)

I2 (aq)

d)

Mn2+(aq)

29.

Which of these is not a redox reaction?

a)

A. Cu2O + H2SO4 → CuSO4 + Cu + H2O

b)

B. MgO + 2HCl → MgCl2 + H2O

c)

C. SnCl2 + HgCl2 → Hg + SnCl4

d)

D. MnO2 + 4HCl → MnCl2 + 2H2O + Cl2

30.

What factor determines the feasibility of a reaction?

a)

Change in entropy

b)

Change in enthalpy

c)

Both change in entropy and change in enthalpy

d)

None of the above

31.

Which reaction has a +ΔS ?

a)

AgNO3(aq) + NaCl(aq) → AgCl(s) + NaNO3(aq)

b)

H2O(g) + CO2(g) → H2CO3(aq)

c)

H2(g) + I2(g) → 2Hl(g)

d)

C2H2O2(g) → 2CO(g) + H2(g)

32.
Entropy always increases when
a)
enthalpy decreases.
b)
temperature decreases.
c)
temperature increases.
d)
volume increases.
33.

What information do we need to perform a calculation of Gibbs Free Energy?

a)

Enthalpy of the reaction.

b)

Entropy of the reaction.

c)

The temperature of the reaction in Kelvin.

d)

All of the above are needed.

34.

Choose the correct correlation between Gibbs free energy and feasibility.

a)

a reaction to be feasible, ΔG has to be negative.

b)

a reaction to be feasible, ΔG has to be positive.

c)

a reaction to be feasible, ΔG has to be zero

d)

no correlation between ΔG and feasibility

35.

Which combination of ΔH and ΔS NEVER has a spontaneous reaction?

a)

+ΔH and +ΔS

b)

+ΔH and -ΔS

c)

-ΔH and -ΔS

d)

-ΔH and +ΔS

36.

O- (g) + e- --> O2- (g)

a)

1st electron affinity

b)

2nd electron affinity

c)

3rd electron affinity

d)

4th electron affinity

37.

The more negative the enthalpy of formation of a compound.......

a)

the less stable the compound is

b)

the more stable the compound is

c)

the more soluble the compound is

d)

none of these

38.

First electron affinity of an element is usually ________ and second electron affinity is ____________.

a)

exothermic, endothermic.

b)

exothermic, exothermic.

c)

endothermic, endothermic.

d)

endothermic, exothermic.

39.

What does Kp relate to in a reversible reaction?

a)

The ratio of gaseous products to gaseous reactants at equilibrium

b)

The amounts of solid products and reactants at equilibrium.

c)

The temperature of the reaction.

d)

The pressure of the system.

40.

Which of the following statements is true about the equilibrium constant (Kc)?

a)

It is affected by the concentration of reactants.

b)

It is affected by the presence of a catalyst.

c)

It is affected by the temperature of the system.

d)

It is affected by the pressure of the system.

41.

What is y?

a)

order of reaction with respect to reactant A

b)

order of reaction with respect to reactant B

c)

overall order of reaction

d)

coefficient of reaction B in a balanced equation

42.

How do we find the value of x and y?

a)

from experiments

b)

from the balanced chemical equations

c)

from the data booklets

d)

from the textbooks

43.

What order is that with respect to this reactant?

a)

0

b)

3

c)

2

d)

1

44.

When the concentration of a reactant doubles, the reaction rate increases 4 times. What order is it with respect to this reactant?

a)

0

b)

1

c)

2

d)

3

45.

For the hypothetical reaction, 2 A + B → C, what is the rate law for this reaction?

a)

Rate= k[A][B]

b)

Rate= k[A]2[B]

c)

Rate= k[B]2

d)

Rate= k[A][B]2

46.

Inert pair effect is......

a)

the tendency of s2 pair of electrons in an atom to stay paired leading to a lower oxidation state

b)

the tendency of s2 pair of electrons in an atom to stay paired leading to a higher oxidation state

c)

the tendency of s2 pair of electrons in an atom to become involved in bonding

d)

none of these

47.

Which of the halogens is the strongest reducing agent?

a)

bromide

b)

chloride

c)

iodide

d)

fluoride

48.

What is a buffer solution?

a)

A solution that is resistant to changes in pH

b)

A solution that accepts changes in pH

c)

Any solution containing an acid and a base

d)

None of these

49.

What is the pH at the equivalence point.

a)

The pH is ~4.5

b)

The pH is ~6.0

c)

The pH is ~8.5

d)

The pH is ~12.0

50.

What happens to the pH of a buffer solution when a small amount of strong acid is added, according to the Henderson-Hasselbalch equation?

a)

The pH increases significantly

b)

The pH decreases significantly

c)

The pH remains relatively stable

d)

The pH becomes neutral