İTÜ GELİŞTİRME VAKFI
ÖZEL EKREM ELGİNKAN LİSESİ
Term
Lesson
Unit
Subject
Date
2nd
Chemistry
Unit 5-6-7
Review
25.04-03.05 2015
Class: 10-IB
Number:
Name- Surname
1.
2.
What is the function of iron in the Haber process?
A.
It shifts the position of equilibrium towards the products.
B.
It decreases the rate of the reaction.
C.
It provides an alternative reaction pathway with a lower activation energy.
D.
It reduces the enthalpy change of the reaction.
Hydrochloric acid is reacted with large pieces of calcium carbonate, the reaction is then
repeated using calcium carbonate powder. How does this change affect the activation energy
and the collision frequency?
Activation energy
3.
Collision frequency
A.
increases
increases
B.
stays constant
increases
C.
increases
stays constant
D.
stays constant
stays constant
Which statement is true about using sulfuric acid as a catalyst in the following reaction?
+
H ( aq )
CH3–CO–CH3(aq) + I2(aq) 

→ CH3–CO–CH2–I(aq) + HI(aq)
I.
The catalyst increases the rate of reaction.
II.
The catalyst lowers the activation energy for the reaction.
III.
The catalyst has been consumed at the end of the chemical reaction.
A.
I and II only
B.
I and III only
C.
II and III only
D.
I, II and III
(Total 1 mark)
IB Questionbank Chemistry
1
4.
Excess magnesium, was added to a beaker of aqueous hydrochloric acid. A graph of the mass of
the beaker and contents was plotted against time (line 1).
Mass
1
2
Time
What change in the experiment could give line 2?
5.
A.
The same mass of magnesium in smaller pieces
B.
The same volume of a more concentrated solution of hydrochloric acid
C.
A lower temperature
D.
A more accurate instrument to measure the time
Which quantities in the enthalpy level diagram are altered by the use of a catalyst?
Enthalpy
I
II
III
Time
6.
A.
I and II only
B.
I and III only
C.
II and III only
D.
I, II and III
In a reaction that occurs in 50 g of aqueous solution, the temperature of the reaction mixture
increases by 20 °C. If 0.10 mol of the limiting reagent is consumed, what is the enthalpy change
(in kJ mol–1) for the reaction? Assume the specific heat capacity of the solution
= 4.2 kJ kg–1 K–1.
A.
–0.10 × 50 × 4.2 × 20
B.
–0.10 × 0.050 × 4.2 × 20
C.
− 50 × 4.2 × 20
0.10
D.
− 0.050 × 4.2 × 20
0.10
IB Questionbank Chemistry
2
7.
Use the average bond enthalpies below to calculate the enthalpy change, in kJ, for the following
reaction.
H2(g) + I2(g) → 2HI(g)
8.
9.
10.
A.
+290
B.
+10
C.
–10
D.
–290
Bond
Bond energy / kJ mol–1
H–H
440
I–I
150
H–I
300
How much energy, in joules, is required to increase the temperature of 2.0 g of aluminium from
25 to 30 °C? (Specific heat of Al = 0.90 J g–1 K–1).
A.
0.36
B.
4.5
C.
9.0
D.
54
Which combination is correct for a chemical reaction that absorbs heat from the surroundings?
Type of reaction
ΔH at constant pressure
A.
Exothermic
Positive
B.
Exothermic
Negative
C.
Endothermic
Positive
D.
Endothermic
Negative
Using the equations below:
C(s) + O2(g) → CO2(g)
∆Hο = –394 kJ mol–1
Mn(s) + O2(g) → MnO2(s)
∆Hο = –520 kJ mol–1
What is ∆H, in kJ, for the following reaction?
MnO2(s) + C(s) → Mn(s) + CO2(g)
A.
914
B.
126
C.
–126
IB Questionbank Chemistry
3
D.
11.
12.
–914
Which statement is always correct for a chemical reaction at equilibrium?
A.
The rate of the forward reaction equals the rate of the reverse reaction.
B.
The amounts of reactants and products are equal.
C.
The concentration of the reactants and products are constantly changing.
D.
The forward reaction occurs to a greater extent than the reverse reaction.
An increase in temperature increases the amount of chlorine present in the following
equilibrium.
PCl5(s)
PCl3(l) + Cl2(g)
What is the best explanation for this?
13.
A.
The higher temperature increases the rate of the forward reaction only.
B.
The higher temperature increases the rate of the reverse reaction only.
C.
The higher temperature increases the rate of both reactions but the forward reaction is
affected more than the reverse.
D.
The higher temperature increases the rate of both reactions but the reverse reaction is
affected more than the forward.
What will happen when at a constant temperature, more iodide ions, I–, are added to the
equilibrium below?
I2(s) + I–(aq)
I3–(aq)
A.
The amount of solid iodine decreases and the equilibrium constant increases.
B.
The amount of solid iodine decreases and the equilibrium constant remains unchanged.
C.
The amount of solid iodine increases and the equilibrium constant decreases.
D.
The amount of solid iodine increases and the equilibrium constant remains unchanged.
IB Questionbank Chemistry
4
14.
The sequence of diagrams represents the system as time passes for a gas phase reaction in which
reactant X is converted to product Y.
Diagram 1
t = 7 seconds
Diagram 2
t = 5 minutes
Diagram
t = 10 minutes
Diagram 4
t = 5 days
Time, t
X=
Y=
Which statement is correct?
A.
At t = 5 days the rate of the forward reaction is greater than the rate of the backward
reaction.
B.
At t = 7 seconds the reaction has reached completion.
C.
At t = 10 minutes the system has reached a state of equilibrium.
D.
15.
At t = 5 days the rate of the forward reaction is less than the rate of the backward
reaction.
What changes occur when the temperature is increased in the following reaction at equilibrium?
Br2(g) + Cl2(g)
2BrCl(g)
∆Hο = +14 kJ mol–1
Position of equilibrium
Value of equilibrium constant
A.
Shifts towards the reactants
Decreases
B.
Shifts towards the reactants
Increases
C.
Shifts towards the products
Decreases
D.
Shifts towards the products
Increases
IB Questionbank Chemistry
5