The heat of neutralisation of a strong acid and a strong alkali is 57.0 kJ mol–1. The heat released when 0.5 mole of HNO3 solution is mixed with 0.2 mole of KOH is [KCET 1991; AIIMS 2002; 

(1) 57.0 kJ

(2) 11.4 kJ

(3) 28.5 kJ

(4) 34.9 kJ

Subtopic:  Thermochemistry |
 68%
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints

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

Subtopic:  Enthalpy & Internal energy |
 54%
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints

In the reaction for the transition of carbon in the diamond form to carbon in the graphite form, ΔH is –453.5 cal. This points out that

(1) Graphite is chemically different from diamond

(2) Graphite is as stable as diamond

(3) Graphite is more stable than diamond

(4) Diamond is more stable than graphite

Subtopic:  Thermochemistry |
 75%
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints

Which of the following equations correctly represents the standard heat of formation (ΔHfo) of methane [IIT JEE (Screening) 1992]

(1) C(diamond)+2H2(g)=CH4(g)

(2) C(graphite)+2H2(g)=CH4(l)

(3) C(graphite)+2H2(g)=CH4(g)

(4) C(graphite)+4H=CH4(g)

Subtopic:  Thermochemistry |
 82%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints

In which of the following reactions does the heat change represent the heat of the formation of water

1. 2H2(g)+O2(g)2H2O(l);ΔH=116kcal

2. H2(g)+12O2(g)H2O(l);ΔH=58kcal

3. H+(aq.)+OH(aq.)2H2O(l);ΔH=13.7kcal

4. C2H2(g)+212O2(g)2CO2(g)+H2O(l); ΔH=310kcal

Subtopic:  Thermochemistry |
 85%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints

Based on the following thermochemical equations

H2O(g)+C(s)CO(g)+H2(g);ΔH=131kJ

CO(g)+12O2(g)CO2(g);ΔH=282kJ

H2(g)+12O2(g)H2O(g);ΔH=242kJ

C(s)+O2(g)CO2(g);ΔH=XkJ

The value of X is [CBSE PMT 1992]

(1) –393 kJ

(2) –655 kJ

(3) +393 kJ

(4) +655 kJ

Subtopic:  Thermochemistry |
 79%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints

If enthalpies of formation of C2H4(g), CO2(g) and H2O(l) at 25°C and 1 atm pressure be 52, – 394 and –286 kJ mol–1 respectively, the enthalpy of combustion of C2H4(g) will be [CBSE PMT 1995; AIIMS 1998; Pb. PMT 1999]

(1) +1412 kJ mol–1

(2) –1412 kJ mol–1

(3) +141.2 kJ mol–1

(4) –141.2 kJ mol–1

Subtopic:  Thermochemistry |
 76%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints

Ozone is prepared by passing silent electric discharge through oxygen. In this reaction [AFMC 1998]

(1) Energy is given out

(2) Energy is absorbed

(3) Oxygen is loaded with energy

(4) Oxygen is dissociated into atoms

Subtopic:  Thermochemistry |
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints

Combustion of glucose takes place according to the equation,

C6H12O6+6O26CO2+6H2O H = -72 K cal

Energy required for the production of 1.6 g of glucose is -

(Molecular mass of glucose = 180 g)

1. 0.064 kcal

2. 0.64 kcal

3. 6.4 kcal

4. 64 kcal

Subtopic:  Enthalpy & Internal energy |
 82%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

Which of the following compounds will absorb the maximum quantity of heat when dissolved in the same amount of water ? The heats of solution of these compounds at 25°C in kJ/mole of each solute is given in brackets [AMU (Engg.) 2000]

(1) HNO3(ΔH=33)

(2) KCl(ΔH=+17.64)

(3) NH4NO3(ΔH=+25.5)

(4) HCl(ΔH=74.1)

Subtopic:  Thermochemistry |
 66%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints