Specific Heat Capacity

Q. Define gravitational potential energy.

Q. For hydrogen Oxygen fuel cell, the reaction is 2H2(g) + O2(g) --------> 2H2O(l) Standard energy of formation of H2O = -237.2 kJ/mol. Hence standard EMF of fuel cell is n nt(1) +1.23 V n nt(2) -2.46 V n nt(3) -1.23 V n nt(4) +2.46 V

Q.

Water is used to cool radiators of engines, because

Q. The specific heat of a substance varies with temperature $t{(}^{\circ }C)$ as
$c=0.20+0.14t+0.023t^2\left(cal/g{m}^{\circ }C\right)$ The heat required to raise the temperature of 2 gm of substance from $5^{\circ }Cto{15}^{\circ }C$

1. 24 calorie
2. 56 calorie
3. 100 calorie
4. 82 calorie

Q.

The Calorific Value Of A Fuel Is Expressed In A Unit Called As_____

Q.

The SI unit of water equivalent of calorimeter is_________

Q.

Explain different types of potential energy.

Q.

Why does the volume of a liquid increase when heated?

Q.

Specific heat capacity depends on

1. Mass

2. Material of the body

3. shape of body

4. Density

Q.

Greater the calorific value, better is the fuel ( state True or False). Also write the false statements in their correct form.

1. True
2. False

Q.

Explain, why water is an excellent liquid to use in cooling systems.

Q.

For an object to have gravitational potential energy only, it must be

1. Moving

2. Falling

3. At an elevated position with respect to the ground

4. Accelerating

Q. When is the gravitational potential energy of a body is positive or negative?

Q. Mark the correct option.
(Given:
Q = Heat energy
m = Mass of the object
ΔT = difference in temperature
c = specific heat capacity)

1. $Q=\frac{m\Delta T}{c}$
2. $Q=\frac{c\Delta T}{m}$
3. $Q=\frac{mc}{\Delta T}$
4. $Q=mc\Delta T$

Q.

The factor not needed to calculate heat lost or gained when there is no change of state is:

1. Weight

2. Specific heat

3. Relative density

4. Temperature change

Q. Do a body possess energy even if it does zero work?

Q.

Why water is an excellent substance for use in cooling substances?

Q. A wooden piece piece gets heated easily compared to an iron piece. Consider the mass of both the substances are equal.

1. True
2. False

Q.

The amount of heat energy required to raise the temperature of $1g$ of water from 14.5${}^{0}C$ to 15.5${}^{0}C$ is

1. 1^oC to 2^oC

2. 10^oC to 11^oC

3. 14.5^oC to 15.5^oC

4. None of these

Q.

A liquid of mass of 100 g at 120 °C is poured into the water at 20 °C. The final temperature recorded is 40 °C. If the specific heat capacity of the liquid is 0.8 Jg^-1 °C^-1, calculate the initial mass of water.

Q.

Assertion (A): Water is used in car radiators as a coolant.

Reason (R): Water has high specific heat capacity.

1. Both A and R are true and R is the correct explanation of A.

2. Both A and R are true, but R is not the correct explanation of A.

3. A is true and R is false.

4. A is false and R is true.

Q.

540 g of ice at $0^{\circ }C$ is mixed with 540 g of water at ${80}^{\circ }C$. The final temperature of the mixture is

1. 0°C

2. 40°C

3. 80°C

4. Less than 0°C

Q. The heat produced on complete combustion of $10$ kg of fuel could raise the temperature of $2$ kg of water from ${20}^o$ to ${70}^o$ Calculate the calorific value.

1. $4.186\times {10}^{-3}$ J/kg
2. $4.186\times {10}^{-2}$ J/kg
3. $4.186\times {10}^{-4}$ J/kg
4. $4.186\times {10}^{-8}$ J/kg

Q.

The entire $8400J$ energy is converted into heat to raise the temperature of $1kg$ of water. What will be the rise in temperature? The specific heat of water is $4200Jk{g}^{-1}°C^{-1}$.

Q.

State in brief, the meaning of each of the following:

The heat capacity of a body is $50{\mathrm{J}}^{\circ }{\mathrm{C}}^{-1}$

Q. The specific heat of a substance varies with temperature $t{(}^{\circ }C)$ as
$c=0.20+0.14t+0.023t^2\left(cal/g{m}^{\circ }C\right)$ The heat required to raise the temperature of 2 gm of substance from $5^{\circ }Cto{15}^{\circ }C$

1. 24 calorie
2. 56 calorie
3. 82 calorie
4. 100 calorie

Q. A sample of oxygen at NTP has volume $V$ and a sample of hydrogen at NTP has volume $4V$. Both the gases are mixed and the mixture is maintained at NTP, if the speed of sound in hydrogen at NTP is $1270m{s}^{-1}$, then calculate the speed of sound in mixture.

Q.

(i) Why does a bottle of soft drink cool faster when surrounded by ice cubes than by ice-cold water, both at $0°C$?

(ii) A certain amount of heat $Q$ will warm $1g$ of material $X$ by $3°C$ and $1g$of material $Y$ by $4°C$. Which material has a higher specific heat capacity?

Q.

In an experiment $4.5\mathrm{kg}$ of a fuel was completely burnt. The heat produced was measured to be $1,80,000\mathrm{kJ}$. Calculate the calorific value of the fuel(in $\mathrm{kJ}/\mathrm{kg}$)?

Q. 50 g of copper is heated to increase its temperature by ${10}^{\circ }C.$ If the same quantity of heat is given to 10 g of water, the rise in its temperature is:
Specific heat of copper is $420Jk{g}^{-1}{}^{\circ }C$.

1. $5^{\circ }C$
2. $6^{\circ }C$
3. $7^{\circ }C$
4. $8^{\circ }C$