Multiple Choice QuestionsWhich of the following species is not electrophilic in nature?
Cl+
BH3
H3O+
H3O+
C.
H3O+
Electrophiles are electron deficient species. Among the given H3O+ has lone pair of electron for donation, thus, it is not electron deficient and hence, does not behave like an electrophile.
Three moles of an ideal gas expanded spontaneously into the vacuum. The work done will be
infinte
3 J
9 J
9 J
D.
9 J
W = pext. ΔV
For vaccum,
ptext = 0
therefore,
W = 0 ΔV = 0
A 0.66 kg ball is moving with a speed of 100 m/s. The associated wavelength will be
(h = 6.6 x 10-34 Js)
6.6 x 10-32 m
6.6 x 10-34 m
1 x 10-35 m
1 x 10-35 m
C.
1 x 10-35 m
Among the elements Ca, Mg, P and Cl, the order of increasing atomic radii is
Mg< Ca < Cl < P
Cl < P < Mg < Ca
P < Cl < Ca < Mg
P < Cl < Ca < Mg
B.
Cl < P < Mg < Ca
With the increase in the number of electron in the same shell, the atomic radii decrease due to increase in effective nuclear charge. However, atomic radii increases, as the number of shells increases. Thus, on moving down a group atomic radii increases.
The electronic configuration of the given elements is
Mg12 = [Ne] 3s2
Ca20 = [Ar] 4s2
P15 = [Ne]3s2 3p3
Cl17 = [Ne] 3s2 3p5
In Mg, P and Cl, the number of electrons is increasing in the same shell thus, the order of their atomic radii is
Cl <P < Mg
In Ca, the electron is entering in the higher shell, thus, it has the highest atomic radii among the given. Thus, the order of radii is
Cl < P < Mg < Ca
Some statement about heavy water are given below
A) Heavy water is used as a moderator in nuclear reactors.
B) Heavy water is more associated than ordinary water.
C) Heavy water is more effective solvent than ordinary
A and B
A, B and C
B and C
B and C
A.
A and B
Heavy water is used as a moderator in nuclear reactors. Its boiling point is higher as compared to the ordinary water. Thus, it is more associated as compared to ordinary water. The dielectric constant is however higher for H2O, thus, H2O is a more effective solvent than heavy water (D2O).
Among the following which one has the highest cation to anion size ratio?
CsI
CsF
LiF
LiF
B.
CsF
The order of size of given cations is
Li+ < Na+ < Cs+
and the order of the size of given anions is
In which of the following molecules the central atom does not have sp3 hybridisation?
CH4
SF4
BF4-
BF4-
B.
SF4
When the number of hybrid orbitals, H is 4, the hybridization is sp3 hybridization
Thus, only in SF4 the central atom does not have sp3 hybridisation.
The reaction,
2A (g) + B (g) ⇌ 3C (g) + D (g)
is begun with the concentrations of A and B both at an initial value of 1.00 M. When equilibrium is reached, the concentration of D is measured and found to be 0.25 M. The value for the equilibrium constant for this reaction is given by the expression
[(0.75)3 (0.25)] / [(1.00)2 (1.00)]
[(0.75)3 (0.25) ] / [(0.50)2(0.75)]
[(0.75)3(0.25)] / [(0.50)2(0.75)]
[(0.75)3(0.25)] / [(0.50)2(0.75)]
B.
[(0.75)3 (0.25) ] / [(0.50)2(0.75)]
Match List I (equation) with List II (types of the process) and select the correct option.
|
List I (Equations)
|
List II (Types of process)
|
||
|
A |
KP > Q |
1 |
Non-spontaneous |
|
B |
ΔGo < RT In Q |
2 |
Equilibrium |
|
C |
KP = Q |
3 |
Spontaneous and endothermic |
|
D |
T> ΔH/ ΔS |
4 |
Spontaneous |
|
A
|
B
|
C
|
D
|
|
1
|
2
|
3
|
4
|
| A | B | C | D |
| 3 | 4 | 2 | 1 |
| A | B | C | D |
| 4 | 1 | 2 | 3 |
| A | B | C | D |
| 4 | 1 | 2 | 3 |
C.
| A | B | C | D |
| 4 | 1 | 2 | 3 |
A) When KP > Q, the reaction goes in the forward direction, ie, the reaction is spontaneous.
B) Given ΔGo < RT lnQ, thus, ΔGo = + ve and hence, the reaction is non-spontaneous.
C) At equilibrium, Kp = Q
The pressure exerted by 6.0 g of methane gas in a 0.03 m3 vessel at 129o C is (Atomic masses C = 12.01, H = 1.01 and R = 8.314 JK-1 mol-1)
215216 Pa
13409 Pa
41648 Pa
41648 Pa
C.
41648 Pa
Given,
Volume , V = 0.03 m3
Temperature, T = 129 + 273 = 402 K
mass of methane, w = 6.0 g
mol. Mass of methane, M = 12.01 + 4 x 1.01 = 16.05
From, ideal gas equation,
pV = nRT
