A solution of 500 ml of 0.2 M KOH and 500 ml of 0.2 M HCl is mixed and stirred; the rise in temperature is T1. The experiment is repeated using 250 ml each of solution, the temperature raised is T2. Which of the following is true .
(1) T1 = T2
(2) T1 = 2T2
(3) T1 = 4T2
(4) T2 = 9T1
The heat of formation of HCl(g) from the reaction
H2(g) + Cl2(g) ; is
1. +44 kcal
2. -44 kcal
3. +22 kcal
4. -22 kcal
The heat of neutralisation of HCl by NaOH is -55.9 kJ/mole. If the heat of neutralisation of HCN by NaOH is -12.1 kJ/mole, then energy of dissociation of HCN is-
1. -43.8 kJ
2. 43.8 kJ
3. 68 kJ
4. -68 kJ
In which case of mixing of a strong acid and a base, each of 1(N) concentration, temperature-increase is the highest ?
1. 20 ml acid and 30 ml alkali
2. 10 ml acid and 40 ml alkali
3. 25 ml acid and 25 ml alkali
4. 35 ml acid and 15 ml alkali
The heats of neutralisation of four acids A, B, C and D are -13.7, -9.4, -11.2 and -12.4 kcal respectively when they are neutralised by a common base. The acidic character obeys the order :
1. A>B>C>D
2. A>D>C>B
3. D>C>B>A
4. D>B>C>A
If a process is both endothermic and spontaneous, then :
1.
2.
3.
4.
The bond energies of C=C and C-C at 298 K are 590 and 331 kJ mol-1 respectively. The enthalpy of polymerization per mole of ethylene is
1. -70 kJ
2. -72 kJ
3. 72 kJ
4. -68 kJ
The gas absorbs 100 J heat and is simultaneously compressed by a constant external pressure of 1.50 atm from 8 lit. to 2 lit. in volume. Hence will be-
1. -812 J
2. 812 J
3. 1011 J
4. 911 J
The standard heat of combustion of Al is -837.8 kJ mol-1 at which of the following releases 250 kcal of heat ?
1. The reaction of 0.624 mol of Al
2. The formation of 0.624 mol of Al2O3
3. The reaction of 0.312 mol of Al
4. The formation of 0.150 mol of Al2O3
Following reaction occurs at :
1. -45.65 kJ
2. -28.53 kJ
3. -22.82 kJ
4. -57.06 kJ