HARD
11th CBSE
IMPORTANT
Earn 100

The ratio of Cp value of a triatomic gas to the Cv value of a monatomic gas is

40% studentsanswered this correctly

Important Questions on Thermodynamics

HARD
11th CBSE
IMPORTANT
In a constant volume calorimeter, 3.5 g of a gas with molecular weight 28 was burnt in excess oxygen at 298.0K. The temperature of the calorimeter was found to increase from 298.0 K to 298.45 K due to the combustion process. Given that the heat capacity of the calorimeter is 2.5 KJ K-1, the numerical value for the enthalpy of combustion of the gas in KJ mol-1 is
HARD
11th CBSE
IMPORTANT

One mole of an ideal gas is taken from ab along two paths denoted by the solid and the dashed lines as shown in the graph below. If the work done along the solid line path is Ws and that along the dotted line path is Wd, then the integer closest to the ratio WdWs is

Question Image

HARD
11th CBSE
IMPORTANT

The surface of copper gets tarnished by the formation of copper oxide. N2 gas was passed to prevent the oxide formation during heating of copper at 1250 K. However, the N2 gas contains 1 mole % of water vapour as impurity. The water vapour oxidise copper as per the reaction given below :

2 Cu(s)+H2OCu2O+H2(g)

PH2 is the minimum partial pressure of H2 (in bar) needed to prevent the oxidation at 1250 K. The value of

 ln (PH2) is...........

(Given : total pressure= 1 bar, R (universal gas constant) = 8 JK-1,mol-1, ln10=2.3, Cu (s) and Cu2O (s) are mutually immiscible

At 1250 K:  2 Cu (s)+12O2 (g)Cu2O(s), G°=-78,000 J mol-1

H2 (g)+12O2 (g)H2O(g),G°=-1,78000 J mol-1

G is Gibbs energy)

 

 

 

HARD
11th CBSE
IMPORTANT
50 ml of 0.10 M Ba(OH)2 is added to 50 ml of 0.10 M H2SO4.The rise in temperature is T1. If experiment is repeated by taking 100 ml of each solution, the rise in temperature is T2. Then
HARD
11th CBSE
IMPORTANT
Enthalpies of formation of K+ (aq), Cl-(aq) and KCl(s) are -60.0, -40.0, -104.0, Kcal mol-1. If one mole of KCl(s) is dissolved in large excess of water at 25C, the enthalpy of solution will be
HARD
11th CBSE
IMPORTANT

500 ml of 0.1 M H2SO4was added into 1L of 0.1M NaOH  solution. The heat evolved was x calories. If further 500 ml of H2SO4is added into the solution, now heat evolved will be

EASY
11th CBSE
IMPORTANT

Calculate the enthalpy of formation of sucrose (C12H22O11) from the following data :-

C12H22O11+12O212CO2+11H2O, ΔH=5200.7 kJ mol-1.

C+O2CO2, ΔH=394.5 kJ mol-1.

H2+12O2H2O, ΔH=285.8 kJ mol-1.

EASY
11th CBSE
IMPORTANT

Calculate the enthalpy of reaction for COg+12O2gCO2g.

Given,

Cs+O2gCO2g, H=-393.5 kJ mol-1 and Cs+12O2gCOg, H=-110.5 kJ mol-1.