Specific Heat Capacity

IMPORTANT

Specific Heat Capacity: Overview

This topic covers concepts such as Heat Capacity, Specific Heat Capacity, Molar Specific Heat Capacity, Specific Heat Capacity of Water, and Variation of Specific Heat Capacity of Water with Temperature.

Important Questions on Specific Heat Capacity

MEDIUM
IMPORTANT

The molar heat capacity of water at constant pressure is  75J K1 mol1. When 1kJ of heat is supplied to 100g of water, which is free to expand, the increase in temperature of water is

                               

MEDIUM
IMPORTANT

Two different liquids of same mass are kept in two identical vessel, which are placed in a freezer that extracts heat from them at the same rate causing each liquid to transform into a solid. The schematic figure below shows the temperaure T vs time t plot for the two materials. We denote the specific heat in the liquid states to be CL1 and CL2 for materials 1 and 2 respectively, and latent heats of fusion U1 and U2 respectively.

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Choose the correct option.

EASY
IMPORTANT

200 g water is heated from 40 oC to 60 oC . Ignoring the slight expansion of water, the change in its internal energy is close to (Given specific heat of water =4184 J/kg/K):

EASY
IMPORTANT

Water is used as a coolant because 

HARD
IMPORTANT

A current carrying wire heats a metal rod. The wire provides a constant power P to the rod. The metal rod is enclosed in an insulated container. It is observed that the temperature T in the metal rod changes with time t as:

Tt=T01+βt1/4

where β is a constant with appropriate dimension while T0 is a constant with dimension of temperature. The heat capacity of the metal is:

EASY
IMPORTANT

A person weighing 50 kg takes in 1500 kcal diet per day. If this energy were to be used in heating the body of person without any losses, then the rise in his temperature is (specific heat of human body =0.83 cal g-1 -1 )

MEDIUM
IMPORTANT

Amongst object A and B, if the specific heat of object A is less than of object B, then 

MEDIUM
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The amount of heat required to raise the temperature of 1 kg mass of water through 1 K is called its

MEDIUM
IMPORTANT

The amount of heat required to raise the temperature of 1 kg mass of water through 1 K is called its

MEDIUM
IMPORTANT

Specific heat of a substance is given by S=(1+2T) J kg-1 K-1, find out amount of heat required to raise the temperature of 2 kg substance from 10°C to 20°C.

MEDIUM
IMPORTANT

The number of degrees of freedom of a gas whose specific heat capacity at constant pressure is 33.24 J mol-1 K-1, is
(universal gas constant =8.31 J mol-1 K-1 )

HARD
IMPORTANT

20 gm ice at -10°C is mixed with m gm steam at 100°C. The minimum value of m so that finally all ice and steam converts into water is,

(Use, sice=0.5 cal gm-1 °C, swater=1 cal gm-1 °CL(melting)=80 cal gm-1 and L (vaporization)=540 cal gm-1.)

HARD
IMPORTANT

Which statement is false for specific heat of water?

MEDIUM
IMPORTANT

During illness an 80 kg man ran a fever of 102.2 °F instead of normal body temperature of 98.6 °F. Assuming that the human body is mostly water, how much heat is required to raise his temperature by that amount?

MEDIUM
IMPORTANT

A source of heat supplies heat at a constant rate to a solid cube. The slope of portion CD of the graphs gives :-

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HARD
IMPORTANT

For next 2 question please follow the same

Molar heat capacity of an ideal gas in the process PVx =  constant is given by

              C = R γ - 1 + R 1 - x

An ideal diatomic gas with C V = 5 R 2   occupies a volume V1 at a pressure P1 . The gas undergoes a process in which the pressure is proportional to the volume. At the end of the process the rms speed of the gas molecules has doubled from its initial value.

The molar heat capacity of the gas in the given process is

HARD
IMPORTANT

When 0.2 kg of brass at 100°C is dropped into 0.5 kg of water at 20 °C, the resulting temperature is 23°C. What must have been the specific heat of brass ?
Specific heat of water is, s=4200 J kg-1 K-1

MEDIUM
IMPORTANT

In a mixture of two gases, we have 1 mole of a certain gas having γ=75 and 1 mole of another gas having γ=43. Calculate the value of γ for the given mixture of gases.

EASY
IMPORTANT

Water is used as a coolant because 

MEDIUM
IMPORTANT

An electric heater supplies 1.8 kW of power in the form of heat to a tank of water. How long will it take to heat 100 kg of water in the tank from 10 to 70oC. Assume heat loss to the surrounding to be negligible.