Fundamentals of Thermodynamics

IMPORTANT

Fundamentals of Thermodynamics: Overview

This topic covers concepts, such as, Heat Capacity, Molar Heat Capacity at Constant Volume (Cv), Characteristics of Internal Energy & Sign Conventions for Heat etc.

Important Questions on Fundamentals of Thermodynamics

MEDIUM
IMPORTANT

A piece of metal weighing 100 g is heated to 80°C and dropped into 1 kg of cold water in an insulated container at 15°C. If the final temperature of the water in the container is 15.69°C, the specific heat of the metal in J/g°C. is

MEDIUM
IMPORTANT

When equal volumes of Helium and Neon at same temperature and pressure are mixed, the ratio Cp:Cv of the mixture equals:

EASY
IMPORTANT

Which energy is a part of mechanical energy?

HARD
IMPORTANT

A heat pump is used to draw water from a well. The temperature of the water is 15°C and that of the atmosphere is 40°C. If the amount of water drawn is 10 kg from a depth of 12 m, calculate the amount of heat supplied to the well in kJ.

Express your answer up to nearest integer value.

MEDIUM
IMPORTANT

The process in which the value of U = 0 is:

EASY
IMPORTANT

The quantity of heat (in J) required to raise the temperature of 1.0 kg of ethanol from 293.45 K to the boiling point and then change the liquid to vapor at that temperature is closest to [Given, boiling point of ethanol 351.45 K. Specific heat capacity of liquid ethanol 2.44 J g-1 K-1. Latent heat of vaporisation of ethanol 855 Jg-1 ]

 

EASY
IMPORTANT

An ideal monoatomic gas is subjected to following change.

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If R is the gas constant then the molar heat capacity of the gas for the process is,

EASY
IMPORTANT

If we place 0.5 g Lithium metal in coffee cup calorimeter that already contains 75 ml of water. The specific heat capacity of reaction mixture is 4Jg-1 K-1. Temperature of water is increased from 22°C to 72°C. Then find H for the reaction.

2Lis+2H2Ol2LiOHaq+H2g

HARD
IMPORTANT

The internal energy (U) of an ideal gas is plotted against volume for a cyclic process ABCDA, as shown in the figure.

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The temperature of the gas at B and C are 500 K and 300 K, respectively. The heat absorbed by the gas (in cal/mol) in this cyclic process, is :

EASY
IMPORTANT

How much heat will be required at constant volume at 727°C to form 1.28 kg of CaC2 from CaO(s) and C(s)

Given: ΔfH(CaO,s)=152kcal/mol

ΔfHCaC2,s=14kcal/mol

ΔfH(CO,g)=24kcal/mol

EASY
IMPORTANT

one mole of an ideal gas at 300 K is expanded isothermally from an initial volume of 1  litre to 10 litre. The ΔU for this process is: R=2 cal K-1 mol-1

EASY
IMPORTANT

An ideal gas initially at temperature T1 with γ=5/3 expands adiabatically into vacuum to double its volume. The final temperature T2 is given by:

MEDIUM
IMPORTANT

A water heater, operating on a hydrocarbon fuel heats water flowing at the rate of 5 kg per minute, from 27°C to 77°C. If the heat of combustion of hydrocarbon is 20,000 J/g, how much fuel in g is consumed per minute? (Specific heat of water is 4200 J/Kg-K)

EASY
IMPORTANT

A diatomic ideal gas changes its state from A to B as shown in the figure.

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Choose the correct U versus V graph: (where U is internal energy of the gas)

EASY
IMPORTANT

One gram sample of NH4NO3 is decomposed in a bomb calorimeter temperature increases by 6.12 K. The heat capacity of the system is 1.23 kJ/gram-degree. What is the molar heat of decomposition for NH4NO3?

HARD
IMPORTANT

Which of the following statement is INCORRECT ?

EASY
IMPORTANT

The internal energy of an ideal gas increases during an isothermal process when the gas is :-

EASY
IMPORTANT

A reaction proceeds through two paths I and II to convert XZ.

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What is the correct relationship between QQ1 and Q2 ?

HARD
IMPORTANT

The entropy change accompanying the heating of one mole of helium gas, assuming ideal behaviour, from a temperature of 250 K to a temperature of 1000 k at constant pressure, in  cal K-1mole-1 is ( Give answer to the nearest integer after rounding off.)

ln10=2.3,log2=0.3 

R=2 Cal mol-1K-1  

MEDIUM
IMPORTANT

200 J of heat is provided to the system. Work done on the system is 20 J. What is the change in internal energy?