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
C.
+125 kJ
CH2=CH2 + H2 → CH3 - CH3
H = (BE)reactants - (BE)products
= 4(BE)C - H + (BE)C = C + (BE)H - H - [6(BE)C - H + (BE)C - C]
= -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
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 =