Internal Energy and First Law of Thermodynamics

IMPORTANT

Internal Energy and First Law of Thermodynamics: Overview

This topic covers concepts such as Work Done in Isochoric Process, Work Done in Isothermal Process, First Law of Thermodynamics, Mathematical statement of First Law of Thermodynamics, Work Done in Reversible Adiabatic Process, etc.

Important Questions on Internal Energy and First Law of Thermodynamics

MEDIUM
IMPORTANT

When 1 mol of a gas is heated at constant volume, temperature is raised from 298 to 380 K. If heat supplied to the gas is 500 J, then which statement is correct?

                               

EASY
IMPORTANT

If ΔH is the change in enthalpy and ΔE, the change in internal energy accompanying a gaseous reaction, then

EASY
IMPORTANT

Internal energy and pressure of a gas per unit volume are related as:

MEDIUM
IMPORTANT

3 moles of an ideal gas expands isothermally against a constant pressure of 2 Pascal from 20 L to 60 L.The amount of work involved is

HARD
IMPORTANT

The ratio Kp to Kc of a reaction is 24.63 L atm mol–1 at 27°C. If heat of reaction at constant pressure is 98.8 kcal, calculate the heat of reaction (in kcal) at constant volume? (Report the value in the nearest integer)

(use R values 0.0821lit atm mole-1k-1and 2X10-3 kcal mole-1k-1)

HARD
IMPORTANT

A gas is enclosed in a cylinder with a piston. Weights are added to the piston, giving a total mass of 2.20 kg. As a result, the gas is compressed and the weights are lowered 0.25 m. At the same time, 1.50 J of heat is evolved from the system. Calculate the change in internal energy of the system and report the answer in the nearest integer value

HARD
IMPORTANT

The ratio Kp to Kc of a reaction is 24.63 L atm mol–1 at 27°C. If heat of reaction at constant pressure is 98.6 kcal, what is the heat of reaction (in kcal)  at constant volume?

HARD
IMPORTANT

The specific heat of a certain substance is 0.86 J g-1 K-1. Assuming ideal solution behavior, the energy required (in J) to heat 10 g of 1 molal of its aqueous solution from 300 K to 310 K is closest to :

[Given: molar mass of the substance =58 g mol-1; specific heat of water =4.2 J g-1 K-1]

MEDIUM
IMPORTANT

1.0 mol of a mono-atomic ideal gas is expanded from state (1) to state (2) as shown in the figure. Calculate the work done for the expansion of gas in Joules from state (1) to state (2) at 298 K.

Question Image

MEDIUM
IMPORTANT

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

HARD
IMPORTANT

A thermally insulated rigid container of 1 L volume contains a diatomic ideal gas at room temperature. A small paddle installed inside the container is rotated from the outside, such that the pressure rises by 105 Pa. The change in internal energy is close to

EASY
IMPORTANT

Find the change in the internal energy ΔU of a closed system, when 'w' denotes the  amount of work done by the system and 'q' amount of heat is supplied to the system.

HARD
IMPORTANT

Which factors affect the internal energy ?

MEDIUM
IMPORTANT

What do you mean by the internal energy of a substance?

MEDIUM
IMPORTANT

One mole of an ideal gas at 300 K is expanded isothermally from an initial volume of 1 Litres to 10 litres. The U for this process is (R= 2 cal mol-1 K-1)

EASY
IMPORTANT

U=q+W is mathematical expression for

MEDIUM
IMPORTANT

A sample of gas absorbs 4000 kJ of heat.

Suppose that as the original sample absorbs heat, it expands against atmospheric pressure and does 600 kJ of work on its surroundings. What is U?

MEDIUM
IMPORTANT

A sample of gas absorbs 4000 KJ of heat.

Suppose that in addition to absorption of heat by the sample, the surroundings does 2000 KJ of work on the sample, what is U?

MEDIUM
IMPORTANT

A sample of gas absorbs 4000 kJ of heat. If volume remains constant, what is U?

HARD
IMPORTANT

In the reaction, H2(g)+Cl2(g)2HCl(g) ΔH=-184kJ if 2 moles of H2 react with 2 moles of Cl2, then U is equal to