Thermodynamic Processes

Q.

What is the change in the entropy of water, When ice melts into water?

1. Entropy of water becomes zero.

2. Entropy of water remains same

3. Entropy of water decreases

4. Entropy of water increases.

Q. For a reaction to occur spontaneously

1. ( ∆H + T∆S ) must be negative

2. ∆H must be negative

3. ∆S must be negative

4. ( ∆H − T∆S ) must be negative

Q. Calculate angle strain in cyclohexane. 44 minute Explain how to calculate angle straim

Q. If b1, b2, b3 are stepwise formation constants of MCl, MCl2, MCl3 and K is overall formation constant of MCl3, then in what ways can K be written?

Q. ASSERTION: adiabatic process is always a fast process REASONING: no change in internal energy occurs during a fast process.

Q.

If V is the observed molar volume of real gas and \(V_{id}\) is the molar volume of an ideal gas then Z is___.

1. 

2. 

3. 

4. 

Q. Henry's law constant for $C{O}_2$ in water is $1.67\times {10}^{8}pa$ at $298K$ the quantity of $C{O}_2$ in $500ml$ of soda water when packed under $2.5atm$ pressure is:

1. $0.41mmole$
2. $0.042mole$
3. $0.082mole$
4. $0.82mole$

Q. All formulae of Thermodynamics

Q.

If $CuS{O}_{4\left(s\right)}$ . $5H_2{O}_{\left(s\right)}$ $\leftrightharpoons$$CuS{o}_4$ . $H_2{O}_{\left(s\right)}$ + $2H_{2}O$(g)$K_p$ = 1.0 x ${10}^{-4}$ atm2 at ${250}^{\circ }$. The efflorescent nature of CuSO4 . 5H2O can be noticed when vapour pressure of H2O in atmosphere is:

1. = 7.6 mm

2. depends on nature of substance

3. > 7.6 mm

4. <7.6 mm

Q.

Match the thermodynamic processes given below:

$\begin{array}{cc}\text{Column I}& \text{Column II}\\ \text{A. Freezing of water at 273K and 1 atm}& \text{p. q=0}\\ \text{B. Expansion of 1 mole of an ideal gas into a vacuum under isolated conditions}& \text{q. W=0}\\ \text{C. Mixing of equal volumes of two ideal gases at constant temperature and pressure in an isolated container}& \text{r. ΔSsys<0}\\ \text{D. Reversible heating of H2(g) at 1 atm from 300 K to 600K, followed by reversible cooling to 300K at 1 atm}& \text{s. ΔU=0}\\ & \text{t. ΔG=0}\end{array}$

1. $\left(A\right)\to r,t;\left(B\right)\to q,s,t;\left(C\right)\to p,q,s;\left(D\right)\to p,q,s$

2. $\left(A\right)\to r,t;\left(B\right)\to p,q,s;\left(C\right)\to p,q,s;\left(D\right)\to q,s,t$

3. $\left(A\right);\to q,s,t\left(B\right)\to p,q,s;\left(C\right)\to p,q,s;\left(D\right)\to r,t$

4. $\left(A\right)\to r,t;\left(B\right)\to p,q,s;\left(C\right)\to p,q,s;\left(D\right)\to q,s,t$

Q. Assertion :Entropy change in reversible adiabatic expansion of an ideal gas is zero. Reason: The increase in entropy due to volume increase just compensate the decrease in entropy due to fall in temperature.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Assertion is incorrect but Reason is correct

Q.

A system in which no thermal energy passes into or out of the system is called

1. adiabatic system

2. an open system

3. a reversible system

4. a closed system

Q. Assertion :For an isothermal reversible process $Q=-W$ i.e. work done by the system equals the heat absorbed by the system. Reason: Enthalpy change $\left(△H\right)$ is zero for isothermal process.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Both Assertion and Reason are incorrect

Q.

Which of the following statements on critical constants of gases are correct?

I : Larger the $\frac{T_c}{P_c}$ value of a gas, larger would be the excluded volume.

II : Critical temperature ($T_c$) of a gas is greater than its Boyle's temperature ($T_B$).

III : At the critical point in the Van der Walls gas isotherm.

$⟮\frac{dP}{d{V}_m}⟯T_c=0$

1. I and II

2. I and III

3. II and III

4. I, II and III

Q. What will be the work done when 1mole of a gas expands isothermally from 15l to 50 l against a constant pressure of 1 atm at 25⁰C. What is the work done when 1 mole of a gas expands isothermally from 25l to 250l at a constant pressure of 1 atm and q temperature of 300K.

Q. An ideal monoatomic gas is taken along a process in which pressure varies with temperature as $p=\frac{a}{T}$, where $a$ is constant. Find molar specific heat of the gas for this process in terms of $R$.

Q. what is ENTROPY? predict in which of the following entropy increases or decreases

1. liquid crystallises in to a solid
2. TEMPERATURE OF CRYSTALLINE SOLIDS IS RAISED TO FROM 0K TO 115K

Q.

Predict in which of the following entropy increases or decreases. Give reason a liquid crystallizes into a solid when the temperature of a crystalline solid is raised from 0K to 115K

1. 2NaHCO₃ (s) → Na₂CO₃ + 2CO₂ + H₂O

2. H₂ → 2H (g)

Q. 1 mole of $C{O}_2$ gas at 300 K is expanded under the reversible adiabatic condition such that its volume becomes 27 times.
(a) What is the final temperature?
(b) What is the work done?
Given $\gamma =1.33$ and $C_V=25.08Jmo{l}^{-1}{K}^{-1}$ for $C{O}_2$

1. $T_2=100K,w=5.016J$
2. None of these
3. $T_2=100K,w=-5.016kJ$
4. $T_2=100K,w=5.016kJ$

Q. An ideal gas is taken around the cycle $ABCA$ as shown. The work done in the cyclic process is:

1. $12P_1{V}_1$
2. $6P_1{V}_1$
3. $3P_1{V}_1$
4. $P_1{V}_1$

Q. Why this reaction go almost to completion ? A+BC , K=10^{

Q.

An ideal gas expands in volume from $1\times {10}^{-3}$ to $1\times {10}^{-2}{m}^3$ at 300 K against a constant pressure of $1\times {10}^{5}N{m}^{-2}$. The work done is :

1. $270$ kJ
2. $-900$ kJ
3. $-900$ J
4. $900$ kJ

Q. A fixed mass 'm' of a gas is subjected to transformation of states from K to L to M to N and back to K as shown in the figure.
The succeeding operations that enable this transformation of states are:

1. heating, cooling, heating, cooling
2. cooling, heating, cooling, heating
3. heating, cooling, cooling, heating
4. cooling, heating, heating, cooling

Q. The given figure shows a change of state A to state C by two paths ABC and AC for an ideal gas. Calculate the:

1. $2$
2. $4$
3. $5$
4. $10$

Q. Will the reaction I2 + H2S -> 2HI + S proceed spontaneously at 298K. dGfH for HI is 1.8kJ/mol and H2S is 38.3kJ/mol

Q.

what is adiabatic process?

Q. Calculate the work done when one mole of a perfect gas is compressed adiabatically. The initial pressure and volume of the gas are ${10}^5$ $N/m^2$ and $6$ litres respectively. The final volume of the gas is $2$ litres. Molar specific heat of the gas at constant volume is $3R/2$.

1. $872$J.
2. $772$J.
3. $972$J.
4. $672$J.

Q. What will be the sign of entropy for the change of liquid into its vapour?
b) Define standard enthalpy of fusion, solution, formation.

Q. Two moles of an ideal monoatomic gas are allowed to expand adiabatically and reversibly from 300 K and 200 K. The work done in the system is ($C_v=12.5J/K/mol$)

1. $500kJ$
2. $-2.5kJ$
3. $-6.25kJ$
4. $-12.5kJ$

Q. Work done on the gas in single stage compression is:

1. 36
2. 72
3. 144
4. none of these