The number of oxygen atoms in 4.4gm of CO2 is
1.2 × 1023
6 × 1022
6 × 1023
12 × 1023
A.
1.2 × 1023
Molar mass of CO2 = 12 + 32 = 44
= 0.1 × 6 × 1023 = 6 × 1022
(Since, each CO2 contains two oxygen atoms)
N(oxygen) = 2 × 6 × 1022 = 1.2 × 1023
If the bond energies of H-H, Br-Br and H-Br are 433, 192 and 364 kJ mol-1 respectively, then H° for the reaction-
H2 (g) + Br2 (g) → 2HBr (g) is
-261 kJ
+103 kJ
+261 kJ
-103 kJ
In the reaction,
Fe(OH)3 (s) Fe3+ (aq) + 3OH- (aq), if the concentration of OH- ions is decreased by times, then the equilibrium concentration of Fe3+ will increase by
8 times
16 times
64 times
4 times
The correct statement regarding entropy is
at absolute zero temperature, entropy of a perfectly crystalline solid is zero
at absolute zero temperature, the entropy of a perfectly crystalline substance is positive
at absolute zero temperature, the entropy of all crystalline substances is zero
at 0°C, the entropy of a perfect crystalline solid is zero
Equilibrium constants K1 and K2 for the following equilibria,
I. NO (g) + O2 (g) NO2 (g)
II. 2NO2 (g) 2NO (g) + O2 (g) are related as
K1 =
K2 =
K1 = 2K2
K2 =
CO is a stronger ligand than Cl-, because
CO is a neutral molecule
CO has -bonds
CO is poisonous
CO is more reactive
Which of the following sequence is correct regarding field strength of ligands as per spectrochemical series?
SCN- < F- < CN- < CO
F- < SCN- < CN- < CO
CN- < F- < CO < SCN-
SCN- < CO < F- < CN-
A liquid can exist only
between triple and critical points
at any temperature above melting point
between melting and critical points
between boiling and melting points