Ammonium ion is
neither an acid nor base
both an acid and a base
a conjugate acid
a conjugate base
Heat of neutralisation of weak acid and strong base is less than the heat of neutralisation of strong acid and strong base due to
energy has to be spent for the total dissociation of weak acid
salt of weak acid and strong base is not stable
incomplete dissociation of weak acid
incomplete neutralisation of weak acid
Solubility product of a salt AB is 1 × 10-8 in a solution in which concentration of A is 10-3 M. The salt will precipitate when the concentration of B becomes more than
10-4 M
10-7 M
10-6 M
10-5 M
In a lime kiln to get higher yield of CO2, the measure that can be taken is
to remove
to add more CaCO3
to mamtain high temperature
to pump out CO2
In the reversible reaction,
A(s) + B(g) C (g) + D(g) ΔG° = -350kJ
Which one of the following statements is true?
The entropy change is negative
Equilibrium constant is greater than one
The reaction should be instantaneous
The reaction is thermodynamically not feasible
B.
Equilibrium constant is greater than one
In the reversible reaction,
A(s) + B(g) C (g) + D(g) ΔG° = -350kJ
Since, the randomness increases (because solid is changing into gas), entropy will increase and thus, ΔS is positive. Reversible reaction never undergo to completion (i.e, never be instantaneous).
Forthe given reaction, ΔG° = -350kJ and we know that
ΔG° = -RT log K
-350 = -RT log K
ie, K (equilibrium constant) is greater than one. Moreover, the reaction is thermodynamically feasible.
pH value of which one of the following is not equal to one?
0.1 M CH3COOH
0.1 M HNO3
0.05 M H2SO4
50 cm3 0.4 M HCl + 50 cm3 0.2 M NaOH
The reaction quotient 'Q' is useful in predicting the direction of the reaction. Which of the following is incorrect?
If Qc < Kc, the forward reaction is favoured
If Qc > Kc, the forward reaction is favoured
If Qc >Kc, the forward reaction is favoured and Qc =Kc, no reaction occur.
None of these
The solubility of CaF2 in pure water is 2.3 × 10-4 mol dm3. Its solubility product will be:
4.6 × 10-4
4.6 × 10-8
6.9 × 10-12
4.9 × 10-11