Chemistry_Today_April_2017_vk_com_stopthepress

Class XII
This specially designed column enables students to self analyse their
extent of understanding of complete syllabus. Give yourself four
marks for correct answer and deduct one mark for wrong answer.
Self check table given at the end will help you to check your
readiness.
Total Marks : 120
NEET / AIIMS
Only One Option Correct Type
1. The Born Haber cycle for rubidium chloride
(RbCl) is given below (the energies are in
kcal/mol –1 )
Rb (s) + 1/2 Cl 2(g) →
–105
RbCl (s)
→
Rb (g)
→
→
+20.5
–159.5
+28.75
Cl x
(g) →
−
Cl
( g )
→
Rb +
+96.0
( g )
What is the electron affinity of chlorine?
(a) –105 kcal/mol (b) –90.75 kcal/mol
(c) 14.5 kcal/mol (d) 25.75 kcal/mol
2. Which of the following is correct?
(a) Duralumin : Al + Cu + Mg + Ag
(b) German silver : Cu + Zn + C
(c) Gun metal : Cu + Zn + Sn
(d) Solder : Pb + Al
3. The most suitable reagent ‘A’, for the reaction
O
O O
→
A
CH 3
CH 3
is
(a) O 3
(b) H 2 O 2
(c) NaOH-H 2 O 2
(d) m-Cl–(C 6 H 4 COOOH)
4. An organic compound having molecular mass
60 is found to contain C = 20%, H = 6.67% and
N= 46.67% while rest is oxygen. On heating, it gives
NH 3 along with a solid residue. The solid residue
gives violet colour with alkaline copper sulphate
solution. The compound is
(a) CH 3 CONH 2 (b) CH 3 NCO
(c) CH 3 CH 2 CONH 2 (d) (NH 2 ) 2 CO
5. The cubic unit cell of Al (molar mass = 27 g mol –1 )
has an edge length of 405 pm and density 2.7 g cm –3 .
The cubic unit cell is
(a) body centred (b) primitive
(c) edge centred (d) face centred.
6. A reaction was observed for 15 days and the
percentage of the reactant remaining after the days
indicated was recorded in the following table :
Time (days)
0
2
4
6
8
10
12
14
15
Time Taken : 60 Min.
% Reactant remaining
100
50
39
25
21
18
15
12.5
10
Which one of the following best describes the order
and half-life of the reaction?
54 CHEMISTRY TODAY | APRIL ‘17