Work done in the reversible adiabatic process is given by:
1. 2.303 RT log (V2/V1)
2.
3. 2.303 RT log(V1/V2)
4. none of these
When an ideal gas is compressed adiabatically and reversibly, the final temperature is:
1. higher than the initial temperature
2. lower than the initial temperature
3. the same as the initial temperature
4. dependent on the rate of compression
The variation of density (p) of gas with its absolute temperature (T) at constant pressure is best represented by the graph
1. | 2. | ||
3. | 4. |
An ideal gas with adiabatic exponent y is heated at constant pressure and it absorbs Q heat. What fraction of this heat is used to perform external work?
1.
2.
3.
4.
If 32 gm of \(O_2\) at \(27^{\circ}\mathrm{C}\) is mixed with 64 gm of \(O_2\) at \(327^{\circ}\mathrm{C}\) in an adiabatic vessel, then the final temperature of the mixture will be:
1. \(200^{\circ}\mathrm{C}\)
2. \(227^{\circ}\mathrm{C}\)
3. \(314.5^{\circ}\mathrm{C}\)
4. \(235.5^{\circ}\mathrm{C}\)
In the reaction at 300 K
H2(g) + Cl2(g)2HCl(g) = -185 kJ
if 2 mol of H2 completely react with 2 mole of Cl2 to form HCl. What is for this reaction?
(1) 0
(2) -185 kJ
(3) -370 kJ
(4) None of these
When two moles of an ideal gas (Cp, m=R) heated from 300 K to 600 K at constant pressure the change in entropy of gas () is:-
(1) Rln2
(2) -Rln2
(3) 7R ln 2
(4) 5 Rln2
A gas is allowed to expand in a well insulated container against a constant external pressure of 2.5 atm from an initial volume of 2.50 L to a final volume of 4.50 L. The change in internal energy U of the gas in joules will be
(1) 1136.25 J
(2) - 500 J
(3) - 505 J
(4) + 515 J
The heat of combustion of carbon to CO2 is -393.5 kJ/mol. The heat released upon the
formation of 35.2 g of CO2 from carbon and oxygen gas is
1. -315 kJ
2. +315 kJ
3. -630 kJ
4. -3.15 kJ
For a perfectly crystalline solid Cpm = aT3, where a is constant. If Cpm is 0.42 J/K–mol at 10 K, molar entropy at 10 K is
1. 0.42 J/K–mol
2. 0.14 J/K–mol
3. 4.2 J/K–mol
4. zero
At 1000 K water vapour at 1 atm. has been found to be dissociated into H2 and O2 to the extent of 3 x 10–6 %.Calculate the free energy decrease of the system, assuming ideal behaviour.
(1) –ΔG = 90,060 cal
(2) –ΔG = 20 cal
(3) –ΔG = 480 cal
(4) –ΔG = –45760 cal
Equal volumes of monoatomic and diatomic gases at same initial temperature and pressure are mixed. The ratio of specific heats of the mixture (Cp/Cv) will be [AFMC 2002]
(1) 1
(2) 2
(3) 1.67
(4) 1.5
A monoatomic gas of n-moles is heated from temperature T1 to T2 under two different conditions (i) at constant volume and (ii) at constant pressure. The change in internal energy of the gas is
(1) More for (i)
(2) More for (ii)
(3) Same in both cases
(4) Independent of number of moles
Helium at 27°C has a volume of 8 litres. It is suddenly compressed to a volume of 1 litre. The temperature of the gas will be [γ = 5/3]
(1) 108°C
(2) 9327°C
(3) 1200°C
(4) 927°C
During the isothermal mixing of ideal gases at pressure, p, the entropy change per mole for the mixing process is-R where x1, x2,....,xi are the mole fractions of the components, 1, 2,....,i of the mixture. Assuming ideal gas behavior, calculate for the mixing of 0.8 mole of N2 and 0.2 mole of O2.(at and 0.9 atm) [1 eu = cal/deg]
1. 0.9943 eu
2. 0.7533 eu
3. 0.6798 eu
4. 0.7112 eu
For an ideal gas four processes are marked as 1, 2, 3 and 4 on P-V diagram as shown in figure. The amount of heat supplied to the gas in the process 1, 2, 3 and 4 are Q1, Q2, Q3 and Q4 repectively, then correct order of heat supplied to the gas is
[AB is process-1, AC is process-2, AD is adiabatic process-3 and AE is process-4]
1.
2.
3.
4.
The standard change is Gibbs energy for the reaction,
H2OH+ + OH- at 25C is:
1. 100 kJ
2. -90 kJ
3. 90 kJ
4. -100 kJ
The reaction CH4(g) + Cl2(g)CH3Cl(g) + HCl(g)
has =-25 Kcal
Bond | Bond Energy Kcal |
EC-Cl | 84 |
EH-Cl | 103 |
EC-H | X |
ECl-Cl | Y |
X:Y | 9:5 |
From the given data, what is the bond enthalpy of Cl-Cl bond?
1. 70 Kcal
2. 80 Kcal
3. 67.75 Kcal
4. 57.85 Kcal