Which one of the following compounds has the smallest bond angle in its molecule ?
SO2
OH2
SH2
NH3
The solubility in water of a sparingly soluble salt AB2 is 1.0 × 10-5 mol L-1. Its solubility product number will be
4 × 10-15
4 × 10-10
1 × 10-15
1 × 10-10
If at 298 K the bond energies of C-H, C-C, C=C and H-H bonds are respectively 414, 347, 615 and 435 kJ mol-1, the value of enthalpy change for the reaction
H2C=CH2 (g) + H2 (g) → H3C - CH3 (g) at 298 K will be
+250 kJ
-250 kJ
+125 kJ
-125 kJ
The correct order of increasing basic nature for the bases NH3, CH3NH2 and (CH3)2NH is
CH3NH2 < NH3 < (CH3)2NH
(CH3)2NH < NH3 < CH3NH2
NH3 < CH3NH2 < (CH3)2NH
CH3NH2 < (CH3)2NH < NH3
The solubilities of carbonates decrease down the magnesium group due to a decrease in
lattice energies of solids
hydration energies of cations
inter-ionic attraction
entropy of solution formation
B.
hydration energies of cations
Solubilities of carbonates decreases down the group because lattice energy decrease is almost constant while decrease in hydration energy downs sharply, finally difference of hydration energy and lattice energy decrease thus solubility decreases.
Due to the presence of an unpaired electron free radicals are
cations
anions
chemically inactive
chemically reactive
Consider the reaction,
N2 + 3H2 → 2NH3
carried out at constant temperature and pressure. If H and U are the enthalpy and internal energy changes for the reaction, which of the following expression is true?
H = 0
The molecular shapes of SF4, CF4 and XeF4 are
different with 1, 0 and 2 lone pairs of electrons on the central atom, respectively
different with 0, 1 and 2 lone pairs of electrons on the central atom, respectively
the same with 1, 1 and 1 lone pair of electrons on the central atoms, respectively
the same with 2, 0 and 1 lone pairs of electrons on the central atom, respectively
The wavelength of the radiation emitted, when in a hydrogen atom electron falls from infinity to stationary state 1, would be (Rydberg constant = 1.097 × 107 m-1)
91 nm
192 nm
406 nm
9.1 × 10-8 nm
What is the equilibrium expression for the reaction
P4 (s) + 5O2 (g) P4O10 (s) ?
Kc =
Kc =
Kc = [O2]5
Kc =