Assertion (A): van der Waals' forces are reponsible for chemisorptions.
Reason (R): High temperature is favourable for chemisorptions.
The correct answer is:
(A) is false, but (R) is true
Both (A) and (R) are correct and (R) is the correct explanation of A
Both (A) and (R) are correct and (R) is not the correct explanation of (A)
(A) is true, but (R) is false
What are the shapes of ethyne and methane?
Square planar and linear
Tetrahedral and trigonal planar
Linear and tetrahedral
Trigonal planar and linear
In an atom the order of increasing energy of electrons with quantum numbers
(i) n=4, l=1 (ii) n=4, l=0 (iii) n=3, l=2 and (iv) n=3, l=1 is
III < I <IV < II
II < IV < I<III
I <III <II <IV
IV< II <III <I
The number of electrons is the valence shell of the central atom of a molecules is 8. The molecule is
BCl3
BeH2
SCl2
SF6
The ratio of rates of diffusion of gases X and Y is 1 : 5 and that of Y and Z is 1 : 6. The ratio of rates of diffusion of Z and X is
1:30
1:6
30:1
6:1
KMnO4 reacts with KI in basic medium to form I2 and MnO2. When 250ml of 0.1M KI solution is mixed with 250ml of 0.02M KMnO4 in basic medium, what is the number of moles of I2 formed?
0.015
0.0075
0.005
0.01
The oxide of a metal contains 40% of oxygen. The valency of metal is 2. What is the atomic weight of metal?
24
13
40
36
The temperature of K at which ΔG = 0, for a given reaction with ΔH =- 20.5 kJ mol-1 and ΔS=-500 JK-1mol-1 is
-410
410
-2.44
2.44