Calorimetry Physics - Calorimetry

The heat capacity of a body depends on:

1. The heat given.
2. The temperature raised.
3. The mass of the body.
4. The material of the body.

When a hot liquid is mixed with a cold liquid, the temperature of the mixture:

1. First decreases then becomes constant.
2. First increases then becomes constant.
3. Continuously increases.
4. Is undefined for some time and then becomes nearly constant.

The temperature of an object is observed to rise in a period. In this period:

1. Heat is certainly supplied to it.
2. Heat is certainly not supplied to it.
3. Heat may have been supplied to it.
4. Work may have been done on it.

The ratio of specific heat capacity to molar heat capacity of a body:

1. Is a universal constant.
2. Depends on the mass of the body.
3. Depends on the molecular weight of the body.
4. Is dimensionless.

Water equivalent of a body is measured in:

1. Kg
2. Calorie
3. Kelvin
4. m³

In a calorimeter, the heat given by the hot object is assumed to be equal to the heat taken by the cold object. Does it mean that heat of the two objects taken together remaina constant?

The calorie ia defined as 1cal = 4.186 joule. Why not as 1cal = 4J to make the conversions easy?

When a solid melts or a liquid boils, the temperature does not increase even when heat is supplied. Where does the energy go?

Is heat a conserved quantity?

Should a thermometer bulb have large heat capacity or small heat capacity?

The atmospheric temperature in the cities on sea-coast change very little. Explain.

A calorimeter is kept in a wooden box to insulate it thermally from the surroundings. Why is it necesaary?

What is the specific heat capacity of:

1. Melting ice
2. Boiling water?

A person's skin is more severely burnt when put in contact with 1g of steam at 100°C than when put in contact with 1g of water at 100°C. Explain.

Indian style of cooling drinking water is to keep it in a pitcher having porous walls. Water comes to the outer surface very slowly and evaporates. Most of energy needed for evaporation is taken from the water itself and the water is cooled down. Assume that a pitcher contains 10kg of water and 0.2g of water comes out per second. Assuming no backward heat transfer from the atmosphere to the water, calculate the time in which the temperature decrease by 5°C. Specific heat capacity of water = 4200J kg^-1°C^-1 and latent heat of vaporization of water = 2.27 × 10⁶ J kg^-1.

The temperatures of equal masses of three different liquids A, B and C are 12°C, 19°C and 28°C respectively. The temperature when A and B are mixed is 16°C, and when B and C are mixed, it is 23°C. What will be the temperature when A and C are mixed?

An aluminium vessel of mass 0.5kg contains 0.2kg of water at 20°C. A block of iron of mass 0.2kg at 100°C is gently put into the water. Find the equilibrium temperature of the mixture. Specific heat capacities of aluminium, iron and water are 910Jkg^-1-K^-1, 470Jkg^-1-K^-1 and 4200Jkg^-1-K^-1 respectively.

A piece of iron of mass 100g is kept inside a furnace for a long time and then put in a calorimeter of water equivalent 10g containing 240g of water at 20°C. The mixture attains and equilibrium temperature of 60°C. Find the temperature of the furnace. Specific heat capacity of iron = 470J kg^-1°C^-1.