CHEMISTRY MODEL QUESTION PAPER

SET 3

1 Copper oxide is obtained by heating copper carbonate or copper
nitrate contains Copper and Oxygen in the same ratio by weight
a) Which law is illustrated by this observation? 1
b) State the law. 2
2 a) Critical temperature of carbon dioxide and methane are
30.98 oC respectively. Which of these has strong intermolecular force
and why? 2
b) In terms of Charle’s, explain why -273 oC is the lowest possible
temperature. 2
3 a) Write the quantum numbers for the valence electrons of potassium
(19K). 3
b) Calculate the de Broglie wavelength of a body with mass 1 g
travelling at a velocity of 1.0 ms-1 2
c) State Heisenberg’s uncertainty principal. 2
4 The ionisation enthalpy increases from left to right in a period.
a) The ionisation enthalpy of Nitrogen and Oxygen is in the order
N > O. Why? 2
b) Arrange the following ions in the decreasing order of ionic radii.
Mg2+, N3-, F-, Na+, Al+, O2-. 3
5 a) Define bond order? 2
b) Ne2 molecule doesn’t exist. Why? 2
c) The shape of H2O molecule is bent. 2
6 Define entropy? 1
For the melting of ice at 25 oC, H2O (S)  H2O (l), The enthalpy of
fusion is 6.97 kJ mol-1 and entropy of fusion is 25.4 J mol-1K-1.
Calculate the Gibbs energy change and predict whether the process
is spontaneous or not at this temperature. 3
7 a) What are the conditions for getting maximum yield of ammonia?
Why? N2 + 3H2  2NH3 ΔH = -92.4kJ. 3
b) Classify the following compound as Lewis acids and bases.
FeCl3, BF3, NH3, Cl- 2
8 a) Assign oxidation number of the underlined elements
1. KMnO4 2. NaBH4 1
b) Justify that the following reaction is a redox reaction
CuO(S) + H2(g)  Cu(S) + H2O(g) 2
9 a) What causes the temporary and permanent hardness of water? 2
b) Explain one method for the removal of permanent hardness. 2
10 a) What is washing soda? How is it prepared? 3
b) Draw the structure of BeCl2 in vapour phase. 1
11 a) Classify the following oxides as neutral, acidic, basic or
amphoteric. CO, B2O3, SiO2, CO2, Al2O3 2
b) Give reasons.
1) Graphite is used as lubricant
2) Conc. HNO3 can be transported in aluminium containers. 2
12 a) Write the IUPAC name of the following.
1) Cl2CHCH2OH 2) CN
2
b) Which of the following carbocation is the most stable?
(CH3)3CC+H2, (CH3)3C+, CH3CH2C+H2, CH3C+HCH2CH3 1
c) Explain the chemistry of Dumas method. 1
13 a) Explain Markovnikov rule with suitable example. 3
b) Why benzene extra ordinarily stability though it contain 3 double
bonds? 2