KING FAHD UNIVERSITY OF PETROLEUM AND MINERALS
CHEMISTRY DEPARTMENT
CHEM 102-091
MAJOR I-EXAM
TEST CODE NUMBER 001


STUDENT NUMBER:    _____________________________
NAME :                          _____________________________
SECTION NUMBER:    _____________________________

INSTRUCTIONS
1.
Write your student number, name, and section number on the EXAM COVER page.
2.
Write your student number, section number, and your name on your EXAM ANSWER FORM.
3.
Bubble in pencil your student number and your section number on the EXAM ANSWER FORM.
4.
Bubble in pencil on your EXAM ANSWER FORM the correct answer to each of the questions. .
You must not give more than ONE answer per question.
5.
At the end of the exam return the EXAM ANSWER FORM to the proctor.
6.
The exam contains 20 multiple choice questions and the time allowed is 80 min (1 hrs and 20 min). Time will be announced after 40 minutes and again 10 minutes before the end of the exam.

Important constants
Gas Constant (R)
= 0.0821
= 8.31
= 8.31 x 107
L.atm/(mol.K)
J/(mol.K)
g.cm2/(sec2.mol.K)
Planck’s Constant (h)
= 6.626 x 10-34
= 6.626 x 10-34
J.sec/particle kg.m2/(sec.particle)
Velocity of light (c)
= 2.998 x 108
m/sec
Avogadro’s number (N)
= 6.022 x 1023
particles/mole
Bohr’s Constant (RH)
= 2.179 x 10-18
J/particle
Faraday (F)
= 96485
Coulombs
Specific heat of H2O
= 4.18
J/(g.oC)




1.
The following questions refer to the reaction between nitric oxide and hydrogen
    2NO + H2 → N2O + H2O


What is the order of this reaction?
A.
Third order
B.
Second order
C.
First order
D.
Zero order
E.
Fourth order


2.
The reaction has the following rate law:
   

After a period of 2.8e3 s, the concentration of NO falls from an initial value of 2.8 10-3 mol/L to 2.0 10-3 mol/L. What is the rate constant, k?
A.
1.4e–7 M-1/s
B.
5.1e–2 M-1/s
C.
3.1e–1 M-1/s
D.
1.2e–4 M-1/s
E.
2.6e–2 M-1/s


3.
The reaction is known to be zero order in A with a rate constant of 5.0 10-2 mol/L s at 25oC. An experiment was run at 25oC where [A]o = 2.5e–3 M. The half-life for the reaction is
A.
2.5e–2 s
B.
4.2e1 s
C.
5.0e-2 s
D.
5.0e–2 s
E.
7.2e-2 s


4.
The rate constant for a reaction at 40.0oC is exactly 6 times that at 20.0oC. Calculate the Arrhenius energy of activation for the reaction.
A.
6.00 kJ/mol
B.
14.9 kJ/mol
C.
68.3 kJ/mol
D.
8.22 kJ/mol
E.
17.1 kJ/mol


5.
The rate constant k is dependent on
I.
 
the concentration of the reactant.
II.
 
the nature of the reactants.
III.
 
the temperature.
IV.
 
the order of the reaction.
 
A.
none of these
B.
one of these
C.
two of these
D.
three of these
E.
all of these


6.
For the reaction X2 + Y + Z → XY + XZ, it is found that the rate equation is rate = k [X2][Y]. Why does the concentration of Z have no effect on the rate?
A.
The concentration of Z is very small and the others are very large.
B.
Z must react in a step after the rate determining step.
C.
Z is an intermediate.
D.
The fraction of molecules of Z that have very high energies is zero.
E.
The activation energy for Z to react is very high.


7.
For the reaction below, Kp = 1.16 at 800. oC.

If a 46.1-gram sample of CaCO3 is put into a 10.0-L container and heated to 800.oC, what percent of the CaCO3 will react to reach equilibrium?
A.
14.8 %
B.
28.6 %
C.
38.4 %
D.
100.0 %
E.
11.2 %


8.
For the reaction given below, 2.00 moles of A and 3.00 moles of B are placed in a 6.00-L container.

At equilibrium, the concentration of A is 0.222 mol/L. What is the value of K? (Ignore significant figures for this problem.)
A.
1.808
B.
1.447
C.
0.222
D.
6.520
E.
0.501


9.
Consider the following reaction:
      (K = 1.00 10-2)

Given 1.00 mole of HF(g), 0.497 mole of H2(g), and 0.750 mole of F2(g) are mixed in a 5.00-L flask. What will happen as equilibrium is approached?
A.
There will be a net gain in product.
B.
There will be a net gain in reactant.
C.
There will be a net gain in both product and reactant.
D.
There will be no net gain in either product or reactant.
E.
The equilibrium constant will decrease until it equals the reaction quotient.
 


10.
Which of the following is not true for a solution at 25°C that has a hydroxide concentration of 2.5 × 10–6 M?
A.
Kw = 1 × 10–14
B.
The solution is acidic.
C.
The solution is basic.
D.
The [H+] is 4 × 10–9 M.
E.
The Kw is independent of what the solution contains.


11.
Consider the following equilibrium:

with K = 1.6e-5. 1.00 mole of pure NOCl and 9.00e–1 mole of pure Cl2 are placed in a 1.00-L container. Calculate the equilibrium concentration of NO(g).
A.
2.1e–3 M
B.
9.0e–1 M
C.
1.1e0 M
D.
6.0e–3 M
E.
4.2e–3 M


12.
For the reaction

4NH3(g) + 502(g) 4NO(g) + 6H2O(g).
at 25.0°C, the value of K is 1.2 x 10-3. At 50.0°C the value of K is 3.4 x 10-1. This means that the reaction is
A.
exothermic.
B.
endothermic.
C.
never favorable.
D.
More information is needed.
E.
never approaching the equilibrium position.


13.
Diet cola drinks have a pH of about 3.0, while milk has a pH of about 7.0. How many times greater is the H3O+ concentration in diet cola than in milk?
A.
2.3 times higher in diet cola than in milk
B.
400 times higher in diet cola than in milk
C.
0.43 times higher in diet cola than in milk
D.
10,000 times higher in diet cola than in milk
E.
1,000 times higher in diet cola than in milk


14.
The pH of a 0.16 M solution of a weak monoprotic acid, HA, is 2.92. Calculate the Ka for this acid.
A.
0.16
B.
1.2e-3
C.
7.6e–3
D.
9.1e–6
E.
8.3e–11


15.
A 0.172-g sample of NaOH(s) is added to enough water to make 250.0 mL of solution. The pH of this solution is:
A.
1.764
B.
0.764
C.
11.633
D.
12.236
E.
7.935


16.
A 0.16-mol sample of a diprotic acid, H2A, is dissolved in 250 mL of water. Calculate the concentration of A2- in this solution.

(The Ka1 of this acid is 1.0 10-5 and Ka2 is 1.0 10-10)
A.
1.0e–5 M
B.
1.3e–3 M
C.
2.5e–3 M
D.
1.0e–10 M
E.
0.64 M


17.
For which type of titration will the pH be basic at the equivalence point?
A.
Strong acid vs. strong base.
B.
Strong acid vs. weak base.
C.
Weak acid vs. strong base.
D.
Weak acid vs. strong acid.
E.
Weak base vs. strong base.


18.
Which of the following is the correct order for increasing pHs for HNO3, KCl, NH4Cl, KOH, and NaC2H3O2?

(Ka for HC2H3O2 is 1.80 × 10–5, Ka for NH4+ is 5.56 × 10–10).
A.
KCl, NH4Cl, HNO3, KOH, NaC2H3O2
B.
HNO3, KCl, NH4Cl, KOH, NaC2H3O2
C.
NH4Cl, HNO3, KCl, KOH, NaC2H3O2
D.
HNO3, NH4Cl, KCl, NaC2H3O2, KOH
E.
HNO3, NaC2H3O2, KCl, NH4Cl, KOH


19.
A solution contains 0.250 M HA (Ka = 1.0 10-6) and 0.45 M NaA. What is the pH after 0.26 mole of HCl is added to 1.00 L of this solution?
A.
0.59
B.
7.57
C.
5.57
D.
2.06
E.
8.43


20.
What is the molarity of a sodium hydroxide solution if 31.6 mL of this solution reacts exactly with 22.30 mL of 0.253 M sulfuric acid?
A.
0.179 M
B.
0.714 M
C.
7.99 M
D.
0.357 M
E.
0.209 M


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