General Chemistry (CHMS2101)
BSc, Biochemistry - BCHS
Semester: First Semester
Level: 200
Year: 2013
THE UNIVERSITY OF BAMENDA FACULTY OF SCIENCE
DEPARTMENT OF CHEMISTRY
CONTINOUS ASSESSMENT FOR CHMS 2201: GENERAL CHEMISTRY JANUARY
2014
WRITE ALL THE ANSWERS ON THIS PAPER AND ATTACH A PHOTOGRAPHY OF
YOUR FORM B
NAME:
____________________________________________________________________________
1. What does chemistry study? …………………………
2. Classify matter
3. What is the basis used to classify matter in states?
4. Define the following terms:
Pure substance
Compound
Mixture
5. Classify the following in increasing number N of atoms of each sample: 1 g of sodium
(
23
Na); 1 g of potassium (
39
K),1 g of iron (
S6
Fe).
6. Classify the following in Increasing number of molecules of each sample: 27 g of H^O, 3
mol of CH^ (g), 22.4 L of COi(g) at $TP
7. Consider the following representations: A =
B=
D=
. 'Which of them is
(are) not correct?......................................................................Explain
why…………………………………………………………………
b) For each correct representation, give the number of neutrons in the nucleus:
……………………
8. The element rhenium, with two - Naturally occurring isotopes
105
Re and
187
Re has a relative
atomic mass of 186.207 amu. Calculate the natural abundance of each isotope given that their
atomic masses are respectively 164.953 amu and 186.956 amu.
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9. Use the .law to calculate the mass of potassium; chloride produced during the reaction
between 1.205 g of potassium and 6.815 g of chlorine if 3.300 of chlorine remains unreacted.
10. When iron rusts, its mass increases. When a match stick burns, the mass of the ash is less. Do
these observations violate the law of conservation of mass? Explain
11 The bromination reaction of 1S.0 g of butanol
C
4
H
9
OH
, 19.4g using sodium bromide NaBr
and 32.7 g of sulphuric acid H
2
SO
4
yields 17.1 g of C
4
H
9
Br. Which of these reactants is the
limiting reagent?
Calculate the theoretical yield, the actual yi/ld arid ihe percent yield
12. The analysis of a given compound shows that it contains 30.45% carbon, 20.03% oxygen,
45.69% chlorine and hydrogen. The various density of the compound is 5.42 times the density
of air under normal conditions of temperature arid pressure; What are the empirical, molecular
and structural formulas of the compound?
13. What is the Δ
0
vap
of a liquid that has a vapour pressure of 641 torr at 85.2
0
C and a boiling
point of 95.6
o
C at 1atm?
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