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

Subtopic:  Hess's Law |
 56%
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints

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

Subtopic:  Thermochemistry |
 69%
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints

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

Subtopic:  Hess's Law |
 92%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints

advertisementadvertisement

If a process is both endothermic and spontaneous, then :

1. S>0

2. S<0

3. H<0

4. G>0

Subtopic:  Gibbs Energy Change |
 79%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints

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

Subtopic:  Thermochemistry |
 72%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints

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 E will be-

1. -812 J

2. 812 J

3. 1011 J

4. 911 J

Subtopic:  Enthalpy & Internal energy |
 55%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints

advertisementadvertisement

The standard heat of combustion of Al is -837.8 kJ mol-1 at 25C 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

Subtopic:  Thermochemistry |
 65%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints

Following reaction occurs at 25C :

2NOg, 1×10-5 atm+Cl2g, 1×10-2 atm2NOClg, 1×10-2 atmG is :

1. -45.65 kJ

2. -28.53 kJ

3. -22.82 kJ

4. -57.06 kJ

Subtopic:  Gibbs Energy Change |
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints

The bond energies ofCC, C-H, H-H and C=C are 198, 98, 103 and145 kcal respectively. The enthalpy change of the reaction HCCH+H2C2H4 is:

1. 48 kcal

2. 96 kcal

3. -40 kcal

4. -152 kcal

Subtopic:  Enthalpy & Internal energy |
 76%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

advertisementadvertisement

The enthalpies of formation of CO2(g) and CO(g) at 298 K are in the ratio 2.56 : 1. For the reaction,

CO2(g)+C(s)2CO(g), H=177.5kJ,
Hf of CO(g)  is-

1. -150.6 kJ mol-1

2. -113.78 kJ mol-1

3. -130.2 kJ mol-1

4. -141.8 kJ mol-1

Subtopic:  Enthalpy & Internal energy |
 61%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch