General Physical And Inorganic Chemistry Question Paper
General Physical And Inorganic Chemistry
Course:Bachelor Of Environmental Science (Environmental Education)
Institution: Kabarak University question papers
Exam Year:2012
KABARAK
UNIVERSITY
UNIVERSITY EXAMINATIONS
2011/2012 ACADEMIC YEAR
FOR THE DEGREE OF BACHELOR OF ENVIRONMENTAL SCIENCE
ENVS 113: GENERAL PHYSICAL AND INORGANIC CHEMISTRY
DAY: THURSDAY
DATE: 09/08/2012
TIME: 9.00 – 11.00 A.M.
STREAM: Y1S1
INSTRUCTIONS:
Attempt ALL questions
Each question = 17.5 marks
Total = 70%
1. (a) Describe the method used in determining the Relative atomic masses and
percentages abundances of isotopes of elements.
(6 marks)
(b) (i) How many neutrons, protons and electrons are in each of the following atoms or
ions?
(3 marks)
Bi3+
209
, 193
V5+
83
77 Ir
and 51
23
(ii) Calculate the Relative Atomic weight of Zinc using the following percent of
natural abundance and mass of each isotope:
(2.5 marks)
48.6 % 64
67
30Zn,
27.9 % 66
30Zn, and 18.8 %
68
30 Zn, 4.1 %
30 Zn
(c) Monosodium glutamate has the following mass percentage composition:
35.51% C, 4.77 % H, 37.85% O, 8.29% N, and 13.60% Na. What is its molecular
formula if its molar mass is 169 gmol-1?
(6 marks)
2. (a) Define the following terms: (i) Electronegativity (ii) Electron Affinity (4 marks)
(b) (i) Explain why the second ionization energy (IE) of Al is higher than the first I.E.
(2.5 marks)
(ii) Using the orbital notation write the electronic configurations of the following
elements; B, Mg, and P. (Atomic weights: B = 5, Mg = 12, P = 15)
(3 marks)
Page 1 of 3
(c) (i) Differentiate between intramolecular and intermolecular bonds. Give
examples.
(2marks)
(ii) Explain how hydrogen bond and dipole-dipole moments are formed. Give
example in each case.
(4 marks)
3. (a) When aqueous solutions of silver nitrate (AgNO3) and calcium chloride (CaCl2)
are mixed, silver chloride precipitate is formed as a solid while calcium nitrate
remain in solution form.
(8.5 marks)
(i) Write a balanced equation for the reaction.
(1 mark)
(ii) In one experiment 20 mL of aqueous silver nitrate reacted exactly with
25 mL of 0.112 M calcium chloride to form silver chloride. Calculate the
molarity of silver nitrate solution.
(3 marks)
(iii) How many grams of silver nitrate should be weighed out to prepare 100 ml
of silver nitrate used in part (ii). (Atomic masses: Ag = 108, N = 14, O = 16)
(2 marks)
(b) Explain how the following conditions affect rate of reaction:
(2 marks)
(i) Temperature
(ii) Pressure
(c) Given the following data for the reaction A + B ? C
Expt.
Initial Conc. [A]
Initial Conc. [B]
Initial rates for
(M)
(M)
formation of C
1
0.25
0.15
8.0 x 10-5 M/s
2
0.25
0.30
3.2 x 10-4 M/s
3
0.50
0.30
1.28 x 10-3 M/s
(i) Write the rate law expression for the reaction. (1 mark)
(ii) What is the order of reaction with respect to A and B? Give the overall order of
reaction. (3 marks)
(iii) Calculate the rate constant (k). (2 marks)
4. (a) (i) State Le Chatelier’s principle
(1 mark)
(ii) How will the equilibrium of the following reaction be affected by addition of
H2 gas and the removal of CS2 gas, respectively?
(2 marks)
Heat + CH
CS
4(g) + 2H2S(g)
2(g) + 4H2(g)
(iii) At 773 0C, a mixture of CO gas, H2 gas, and CH3OH gas was allowed to come
to equilibrium. The following equilibrium concentrations were then measured:
[CO] = 0.105 M, [H2] = 0.250 M, [CH3OH] = 0.0050 M. Calculate Kc for the
reaction:
(2 marks)
CO
(g) + 2H2(g)
CH3OH(g)
Page 2 of 3
(b) (i) Describe the following terms as used in thermochemistry means
I. System II. Surrounding.
(2 marks)
(ii) Benzene, C6H6 , burns according to the following equations.
2C
6H6(l) + 15O2(g)
12CO2(g) + 6H2O(l) H0 = - 6542 kJ.
What is H0 for the combustion of 1.50 moles of benzene?
(2 Marks)
(c) (i) Write half-reactions and a balanced cell reaction for the galvanic cell.
(3 marks)
Cr(s) Cr3+(aq) Cu2+(qa) Cu(s)
(ii) Make a sketch of a galvanic cell for which the cell notation is
Ag(s) Ag+(aq) Fe3+(qa) Fe(s)
Label the anode and the cathode. Give the changes on each electrode. (5.5 marks)
Page 3 of 3
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