Thermodynamics CBSE Questions & Answers

Thermodynamics

This is Chemistry Class 11 Thermodynamics CBSE Questions & Answers. There are 15 questions in this test with each question having around four answer choices.

Questions & Answers

1
Thermodynamics is the branch of physical science concerned with
  • A
    Potential and its transformations to and from other forms of energy
  • B
    heat and its transformations to and from other forms of energy
    Correct
  • C
    kinetic energy and its transformations to and from other forms of energy
  • D
    mass and its transformations to and from other forms of energy
2
in a closed system,
  • A
    the boundaries prevent the flow of matter out of it
  • B
    the boundaries prevent the flow of matter into or out of it
    Correct
  • C
    the boundaries permit the flow of matter into it
  • D
    the boundaries permit the flow of matter into or out of it
3
in an open system,
  • A
    the boundaries prevent the flow of matter into it
  • B
    the boundaries permit the flow of matter into or out of it
    Correct
  • C
    the boundaries prevent the flow of matter into or out of it
  • D
    the boundaries prevent the flow of matter out of it
4
first law of thermodynamics is a restatement of
  • A
    law of conservation of charge
  • B
    law of conservation of mass
  • C
    law of conservation of energy
    Correct
  • D
    law of conservation of parity
5
According to first law of thermodynamics \(\Delta {\text{U }} = {\text{ q }} + {\text{ w}}\), where
  • A
    q is positive if heat is transferred to the system and w is positive if work is done on the system
    Correct
  • B
    q is negative if heat is transferred to the system and w is negative if work is done on the system
  • C
    q is negative if heat is transferred to the system and w is positive if work is done on the system
  • D
    q is positive if heat is transferred to the system and w is negative if work is done on the system
6
If \({{\text{V}}_{\text{f}}}\) is the final volume and \({{\text{V}}_{\text{i}}}\) is the initial volume and \({{\text{p}}_{{\text{ex}}}}\) the external pressure the work done can be calculated by
  • A
    \( - \mathop \smallint \limits_{{V_i}}^{{V_f}} {p_{ex}}dV\)
    Correct
  • B
    \(\mathop \smallint \limits_0^{{V_f}} {p_{ex}}dV\)
  • C
    \( - \mathop \smallint \limits_{{V_i}}^0 {p_{ex}}dV\)
  • D
    \(\mathop \smallint \limits_{{V_i}}^{{V_f}} {p_{ex}}dV\)
7
For isothermal reversible free expansion of an ideal gas from \({{\text{V}}_{\text{i}}}\) the initial volume to \({{\text{V}}_{\text{f}}}\) the final volume the work done on the gas is
  • A
    \(w = - RTln\left( {\frac{{{V_f}}}{{{V_i}}}} \right)\)
  • B
    \(w = - nRln\left( {\frac{{{V_f}}}{{{V_i}}}} \right)\)
  • C
    \(w = - nRTln\left( {\frac{{{V_f}}}{{{V_i}}}} \right)\)
    Correct
  • D
    \(w = - nTln\left( {\frac{{{V_f}}}{{{V_i}}}} \right)\)
8
Enthalpy is defined as
  • A
    H = U + TV
  • B
    H = U + pV
    Correct
  • C
    H = U + \(\frac{p}{V}\)
  • D
    H = U +n \(\frac{p}{V}\)
9
The molar heat capacity of a substance is the
  • A
    quantity of heat needed to raise the temperature of one mole by one degree celsius
    Correct
  • B
    quantity of heat needed to raise the temperature of one gram by one degree celsius
  • C
    quantity of heat needed to raise the temperature of one mole by one degree Fahrenheit
  • D
    quantity of heat needed to raise the temperature of one kilogram by one degree Fahrenheit
10
The relationship between \({{\text{C}}_{\text{p}}}\) and CV for an ideal gas is
  • A
    \({{\text{C}}_{\text{p}}} - {\text{ }}{{\text{C}}_{\text{V}}} = {\text{ R}}\)
    Correct
  • B
    \({{\text{C}}_{\text{p}}} + {{\text{C}}_{\text{V}}} = {\text{ R}}\)
  • C
    \({{\text{C}}_{\text{p}}} - {\text{ }}{{\text{C}}_{\text{V}}} = {\text{ 2R}}\)
  • D
    \({{\text{C}}_{\text{p}}}{{\text{C}}_{\text{V}}} = {\text{ R}}\)
11
Calorimetry is a branch of science dealing with
  • A
    measuring the amount of work done in a reaction
  • B
    measuring the amount of chemicals consumed
  • C
    measuring the amount of energy transferred as heat
    Correct
  • D
    measuring the maximum pressure developed in a reaction
12
An exothermic process
  • A
    results in a decrease in the temperature of the system
  • B
    results in a decrease in the enthalpy of the system
    Correct
  • C
    results in a increase in the internal energy of the system
  • D
    results in a increase in the enthalpy of the system
13
The enthalpy change of a chemical reaction \({\Delta _{\text{r}}}{\text{H}}\) equals (\({{\text{a}}_{\text{i}}}\) and \({{\text{b}}_{\text{i}}}\) are stoichiometric coefficients)
  • A
    \(\mathop \sum \limits_i {a_i}{H_{products}} \pm \mathop \sum \limits_i {b_i}{H_{reactants}}\)
  • B
    \(\mathop \sum \limits_i {a_i}{H_{products}} - \mathop \sum \limits_i {b_i}{H_{reactants}}\)
    Correct
  • C
    \(\mathop \sum \limits_i {a_i}{H_{products}}\)
  • D
    \(\mathop \sum \limits_i {a_i}{H_{products}} + \mathop \sum \limits_i {b_i}{H_{reactants}}\)
14
Standard enthalpy of fusion or molar enthalpy of fusion is
  • A
    the enthalpy change that accompanies vaporization of one mole of a solid substance in standard state
  • B
    the enthalpy change that accompanies melting of one kg of a solid substance in standard state
  • C
    the enthalpy change that accompanies vaporization of one kg of a solid substance in standard state
  • D
    the enthalpy change that accompanies melting of one mole of a solid substance in standard state
    Correct
15
Standard Molar Enthalpy of Formation is
  • A
    The standard enthalpy change for the formation of one mole of a compound from its elements in at a pressure of 2 bar and 25\(^\circ {\text{ C}}\).
  • B
    The standard enthalpy change for the formation of one mole of a compound from its elements in their most stable states of aggregation
    Correct
  • C
    The standard enthalpy change for the formation of one mole of a compound from its elements in at a pressure of 10 bar and 30\(^\circ {\text{ C}}\).
  • D
    The standard enthalpy change for the formation of one kg of a compound from its elements in their most stable states of aggregation