First Law of Thermodynamics

$1 \mathrm{kg}$ of water at $100°\mathrm{C}$ is converted into steam at $100°\mathrm{C}$ by boiling at atmospheric pressure. The volume of water changes from $1.00\times {10}^{-3} {\mathrm{m}}^3$ as a liquid to $1.671 {\mathrm{m}}^3$ as steam. The change in internal energy of the system during the process will be (Given latent heat of vaporisation $=2257 \mathrm{kJ}/\mathrm{kg}$, Atmospheric pressure $\left.=1\times {10}^5 \mathrm{Pa}\right)$

Given below are two statements:

Statement I: If heat is added to a system, its temperature must increase.

Statement II: If positive work is done by a system in a thermodynamic process, its volume must increase.

In the light of the above statements, choose the correct answer from the options given below

A source supplies heat to a system at the rate of $1000 \mathrm{W}.$ If the system performs work at a rate of $200 \mathrm{W}.$ The rate at which internal energy of the system increases is

The amount of heat supplied to a gas in a system is equal to $1000 \mathrm{J}$, the system in return does $200 \mathrm{J}$ of work on the surrounding. Find change in internal energy of the gas.

If amount of heat given to the system be $80$ Joules and the amount of work done by the system is $-20 \mathrm{J}$ . If initial internal energy of the system is $250 \mathrm{J}$. Final internal energy of the system is

In the case of diatomic gas, the heat given at constant pressure is that part of energy which is used for the expansion of gas, is

What is $∆U$ for the process described by figure. Heat supplied during the process is $q= 200 \mathrm{kJ}$.

ideal gas expands from volume $V_1$to$V_2$,. This may be achieved by either of the three processes: isobaric, isothermal and adiabatic. Let $∆U$ be the change in internal energy of the gas, $Q$ be the quantity of heat added to the system and W be the work done by the gas. Identify which of the following statements is false for$∆U$?
 

$1 \mathrm{g}$ of water at atmospheric pressure has volume of $1 {\mathrm{cm}}^3$ and when boiled it becomes $1681 {\mathrm{cm}}^3$ of steam. The heat of vaporization of water is $540 \mathrm{cal} {\mathrm{g}}^{-1}$. Then the change in its internal energy in this process is 

How the first law of thermodynamics can be justified? Give an example in support of your answer.

An ideal gas is expanded adiabatically at an initial temperature of $300 \mathrm{K}$ so that its volume is doubled. The final temperature of the hydrogen gas is $\left(\gamma =1.4\right)$

In an insulated container of water is stirred with a rod to increase the temperature. Which of the following is true?

$1 \mathrm{kg}$ of water is heated from $40 °\mathrm{C}$ to $70 °\mathrm{C}$, if its volume remains constant, then the change in internal energy is (specific heat of water $=4148 \mathrm{J} {\mathrm{kg}}^{-1} {\mathrm{K}}^{-1}$)

A diatomic gas $\left(C_P=\frac{7}{2}R\right)$ does $200 \mathrm{J}$ of work when it is expanded isobarically. The heat given to the gas in the process is

Two moles of a monoatomic gas undergoes an isobaric process. If the gas temperature is increased by $20°\mathrm{C}$ then the heat absorbed by the gas is (Take $R=8.3 \mathrm{J} {\mathrm{K}}^{-1} {\mathrm{mol}}^{-1}$)

$1.00 \mathrm{kg}$ of liquid water at $100°\mathrm{C}$ undergoes a phase change into steam at $100{}^{\circ }\mathrm{C}$ at $1.0$ atm (take it to be $1.00\times {10}^5 \mathrm{Pa}$). The initial volume of the liquid water was $1.00\times {10}^{-3} {\mathrm{m}}^3$ which is changed to $2.001 {\mathrm{m}}^3$ of steam. Find the change in the internal energy of the system.
[Use heat of vaporization $\simeq 2000 \mathrm{kJ} {\mathrm{kg}}^{-1}$]

In the indicator diagram, we have
(a) Change in internal energy along ABC is $10 \mathrm{J}$.
(b) Work done along path AB $= 20 \mathrm{J}$.
(c) $U_c=5 \mathrm{J}$.
(d) Heat absorbed by the system along path AD is $5 \mathrm{J}$.

Calculate:

(i) Change in internal energy along the path CDA.
(ii) Heat given to the system along path ABC.
(iii) Value of $U_A$
(iv) Change in internal energy along AD.

State first law of thermodynamics.

Consider the following cycle (a-b-c) for ideal gas in the figure: b-c(adiabatic), c-a(isobaric), and a-b (isochoric). Calculate work done by the gas and heat absorbed by the gas for each path, a-b, b-c, c-a. What is the total work done and heat absorbed for the full cycle?

In the diagram shown $Q_{\text{iaf }}=80\mathrm{cal}$ and $W_{\mathrm{ef}}=50$ cal. If $W=-30$ cal for the curved path $f$ value of $Q$ for path $fi$, will be