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

Concept Questions :-

CP and CV and Relation for Real Gas
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The unit of entropy is [CBSE PMT 2002]

(1) J mol–1

(2) JK mol–1

(3) J mol–1 K–1

(4) J–1 K–1 mol–1

Concept Questions :-

Spontaneity and Entropy
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The entropy changed involved in the conversion of 1 mole of liquid water at 373 K to vapour at the same temperature will be $\left[\Delta {H}_{\text{vap}}=2.257kJ/gm\right]$ [MP PET 2002]

(1) 0.119 kJ

(2) 0.109 kJ

(3) 0.129 kJ

(4) 0.120 kJ

Concept Questions :-

Spontaneity and Entropy
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

When a liquid boils, there is [JIPMER 2002]

(1) An increase in entropy

(2) A decrease in entropy

(3) An increase in heat of vaporization

(4) An increase in free energy

Concept Questions :-

Spontaneity and Entropy
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The work done to contract a gas in a cylinder, is 462 joules. 128 joule energy is evolved in the process. What will be the internal energy change in the process [MP PMT 2003]

(1) + 590 joules

(2) – 334 joules

(3) + 334 joules

(4) – 590 joules

Concept Questions :-

Internal Energy and work done
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

For a carnot engine, the source is at 500 K and the sink at 300 K. What is efficiency of this engine [BHU 2004]

(1) 0.2

(2) 0.4

(3) 0.6

(4) 0.3

Concept Questions :-

Enthalpy and It's Type
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

From Kirchhoff's equation which factor affects the heat of reaction [MP PMT 1990]

(1) Pressure

(2) Temperature

(3) Volume

(4) Molecularity

Concept Questions :-

Thermodynamics' Properties and process
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The absolute enthalphy of neutralisation of the reaction $MgO\left(s\right)+2HCl\left(aq\right)\to MgC{l}_{2}\left(aq\right)+{H}_{2}O\left(l\right)$ will be [CBSE PMT 2005]

(1) Less than –57.33 kJ mol–1

(2) –57.33 kJ mol–1

(3) Greater than –57.33 kJ mol–1

(4) 57.33 kJ mol–1

Concept Questions :-

Hess's Law
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The heat of transition (ΔHt) of graphite into diamond would be, where

$C\left(\text{graphite}\right)+{O}_{2}\left(g\right)\to C{O}_{2}\left(g\right);\text{\hspace{0.17em}\hspace{0.17em}}\Delta H=x\text{\hspace{0.17em}}kJ$

$C\left(\text{diamond}\right)\text{\hspace{0.17em}}+{C}_{2}\left(g\right)\to C{O}_{2}\left(g\right);\text{\hspace{0.17em}\hspace{0.17em}}\Delta H=y\text{\hspace{0.17em}}kJ$ [Pb. PET 1985]

(1) $\left(x+y\right)\text{\hspace{0.17em}}kJ\text{\hspace{0.17em}}mo{l}^{-1}$

(2) $\left(x-y\right)\text{\hspace{0.17em}}kJ\text{\hspace{0.17em}}mo{l}^{-1}$

(3) $\left(y-x\right)\text{\hspace{0.17em}}kJ\text{\hspace{0.17em}}mo{l}^{-1}$

(4) None of these

Concept Questions :-

Thermochemistry
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

Given that

$2C\left(s\right)+2{O}_{2}\left(g\right)\to 2C{O}_{2}\left(g\right);\text{\hspace{0.17em}\hspace{0.17em}}\Delta H=-787\text{\hspace{0.17em}}kJ$

${H}_{2}\left(g\right)+\frac{1}{2}{O}_{2}\left(g\right)\to {H}_{2}O\left(l\right);\text{\hspace{0.17em}\hspace{0.17em}}\Delta H=-286\text{\hspace{0.17em}}kJ$

${C}_{2}{H}_{2}\left(g\right)+2\frac{1}{2}{O}_{2}\left(g\right)\to 2C{O}_{2}\left(g\right)+{H}_{2}O\left(l\right);\text{\hspace{0.17em}}\Delta H=-1301\text{\hspace{0.17em}}kJ$

Heat of formation of acetylene is [KCET 1989; Orissa JEE 2005]

(1) –1802 kJ

(2) +1802 kJ

(3) –800 kJ

(4) +228 kJ

Concept Questions :-

Hess's Law