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
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 solubility of CaF2 in pure water is 2.3 ×10-6 mol dm-3. Its solubility product will be:
4.8 ×10-18
48.66 ×10-18
4.9 ×10-11
48.66 ×10-15
Two moles of PCl5 were heated in a closed vessel of 2 L. At equilibrium 40% of PCl5 is dissociated into PCl3 and Cl2.The,value of equilibrium constant is :
0.53
0.267
2.63
5.3
What is the equilibrium expression for the reaction
P4 (s) + 5O2 (g) P4O10 (s) ?
Kc =
Kc =
Kc = [O2]5
Kc =
The temperature dependence of rate constant (k) of a chemical reaction is written in terms of Arrhenius equation, k = Ae-E*/ RT. Activation energy (E*) of the reaction can be calculated by plating
log k vs
log k vs
k vs T
k vs
The heats of combustion of carbon monoxide at constant pressure and at constant volume at 27°C will differ from one another by :
27 cal
54 cal
300 cal
600 cal
Microcosmic salt is
Na4P2O7
Na(NH4)HPO4
Na(NH3)HPO4 4H2O
MgNH4PO4
B.
Na(NH4)HPO4
Microcosmic salt is Na(NH4)HPO4. It is white crystalline solid. It is separated by fractional crystallisation.
It is obtained when NH4Cl and Na2HPO4 are dissolved in hot water and cooled.
NH4Cl + Na2HPO4 → Na(NH4)HPO4 + NaCl
It is used for the detection of certain, basic radicals which forms coloured mixed phosphate with NaPO3.
Na(NH4)HPO4 NaPO3 + NH3 + H2O
NaPO3 + CoO → NaCo.PO4