Laws of Thermochemistry
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CHXI06:THERMODYNAMICS

369517 In which of the following exothermic reactions, the heat liberated per mole is the highest?

1 \(\mathrm{\mathrm{CaO}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{Ca}(\mathrm{OH})_{2}}\)
2 \(\mathrm{\mathrm{SrO}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{Sr}(\mathrm{OH})_{2}}\)
3 \(\mathrm{\mathrm{BaO}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{Ba}(\mathrm{OH})_{2}}\)
4 \(\mathrm{\mathrm{MgO}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{Mg}(\mathrm{OH})_{2}}\)
JEE - 2013
CHXI06:THERMODYNAMICS

369518 Consider the following reaction between zinc and oxygen and choose the correct options out of the options given below :
\(\rm{2 \mathrm{Zn}_{(s)}+O_{2(g)} \rightarrow 2 \mathrm{ZnO}_{(s)} ; \Delta H=-693.8 \mathrm{~kJ} / \mathrm{mol}}\)

1 The enthalpy of two moles of \(\mathrm{\mathrm{ZnO}}\) is less than the total enthalpy of two moles of \(\mathrm{\mathrm{Zn}}\) and one mole of oxygen by \(\mathrm{693.8 \mathrm{~kJ}}\).
2 The enthalpy of two moles of \(\mathrm{\mathrm{ZnO}}\) is more than the total enthalpy of two moles of \(\mathrm{\mathrm{Zn}}\) and one mole of oxygen by \(\mathrm{693.8 \mathrm{~kJ}}\).
3 \(\mathrm{598.3 \mathrm{~kJ} \mathrm{~mol}^{-1}}\) energy is evolved in the reaction.
4 \(\mathrm{693.8 \mathrm{~kJ} \mathrm{~mol}^{-1}}\) energy is absorbed in the reaction.
CHXI06:THERMODYNAMICS

369519 Consider the following statements for the given reactions:
(I) \(\mathrm{\dfrac{1}{2} \mathrm{~N}_{2}(\mathrm{~g})+\dfrac{1}{2} \mathrm{O}_{2}(\mathrm{~g}) \rightarrow \mathrm{NO}(\mathrm{g})}\);
\(\rm{\Delta_{\mathrm{r}} \mathrm{H}^{\mathrm{o}}=90 \mathrm{kJmol}^{-1}}\)
(II) \(\mathrm{\mathrm{NO}(\mathrm{g})+\dfrac{1}{2} \mathrm{O}_{2}(\mathrm{~g}) \rightarrow \mathrm{NO}_{2}(\mathrm{~g})}\);
\(\rm{\Delta_{\mathrm{r}} \mathrm{H}^{\circ}=-74 \mathrm{kJmol}^{-1}}\)
I.
In reaction (I), \(\mathrm{N O(g)}\) is unstable because the energy is released and unstable \(\mathrm{\mathrm{NO}(\mathrm{g})}\) changes into the stable \(\mathrm{\mathrm{NO}_{2}(\mathrm{~g})}\).
(II) The energy is absorbed in reaction (i) , \(\mathrm{\mathrm{NO}(\mathrm{g})}\) is unstable and unstable \(\mathrm{\mathrm{NO}(\mathrm{g})}\) changes into the stable \(\mathrm{\mathrm{NO}_{2}(\mathrm{~g})}\).
Select the correct statements and choose the correct option

1 Only I
2 Only II
3 Both I and II
4 None of these
CHXI06:THERMODYNAMICS

369520 During the evaporation of a liquid,

1 The enthalpy decreases
2 The enthalpy increases
3 The enthalpy remains unchanged
4 The internal energy decreases
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CHXI06:THERMODYNAMICS

369517 In which of the following exothermic reactions, the heat liberated per mole is the highest?

1 \(\mathrm{\mathrm{CaO}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{Ca}(\mathrm{OH})_{2}}\)
2 \(\mathrm{\mathrm{SrO}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{Sr}(\mathrm{OH})_{2}}\)
3 \(\mathrm{\mathrm{BaO}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{Ba}(\mathrm{OH})_{2}}\)
4 \(\mathrm{\mathrm{MgO}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{Mg}(\mathrm{OH})_{2}}\)
JEE - 2013
CHXI06:THERMODYNAMICS

369518 Consider the following reaction between zinc and oxygen and choose the correct options out of the options given below :
\(\rm{2 \mathrm{Zn}_{(s)}+O_{2(g)} \rightarrow 2 \mathrm{ZnO}_{(s)} ; \Delta H=-693.8 \mathrm{~kJ} / \mathrm{mol}}\)

1 The enthalpy of two moles of \(\mathrm{\mathrm{ZnO}}\) is less than the total enthalpy of two moles of \(\mathrm{\mathrm{Zn}}\) and one mole of oxygen by \(\mathrm{693.8 \mathrm{~kJ}}\).
2 The enthalpy of two moles of \(\mathrm{\mathrm{ZnO}}\) is more than the total enthalpy of two moles of \(\mathrm{\mathrm{Zn}}\) and one mole of oxygen by \(\mathrm{693.8 \mathrm{~kJ}}\).
3 \(\mathrm{598.3 \mathrm{~kJ} \mathrm{~mol}^{-1}}\) energy is evolved in the reaction.
4 \(\mathrm{693.8 \mathrm{~kJ} \mathrm{~mol}^{-1}}\) energy is absorbed in the reaction.
CHXI06:THERMODYNAMICS

369519 Consider the following statements for the given reactions:
(I) \(\mathrm{\dfrac{1}{2} \mathrm{~N}_{2}(\mathrm{~g})+\dfrac{1}{2} \mathrm{O}_{2}(\mathrm{~g}) \rightarrow \mathrm{NO}(\mathrm{g})}\);
\(\rm{\Delta_{\mathrm{r}} \mathrm{H}^{\mathrm{o}}=90 \mathrm{kJmol}^{-1}}\)
(II) \(\mathrm{\mathrm{NO}(\mathrm{g})+\dfrac{1}{2} \mathrm{O}_{2}(\mathrm{~g}) \rightarrow \mathrm{NO}_{2}(\mathrm{~g})}\);
\(\rm{\Delta_{\mathrm{r}} \mathrm{H}^{\circ}=-74 \mathrm{kJmol}^{-1}}\)
I.
In reaction (I), \(\mathrm{N O(g)}\) is unstable because the energy is released and unstable \(\mathrm{\mathrm{NO}(\mathrm{g})}\) changes into the stable \(\mathrm{\mathrm{NO}_{2}(\mathrm{~g})}\).
(II) The energy is absorbed in reaction (i) , \(\mathrm{\mathrm{NO}(\mathrm{g})}\) is unstable and unstable \(\mathrm{\mathrm{NO}(\mathrm{g})}\) changes into the stable \(\mathrm{\mathrm{NO}_{2}(\mathrm{~g})}\).
Select the correct statements and choose the correct option

1 Only I
2 Only II
3 Both I and II
4 None of these
CHXI06:THERMODYNAMICS

369520 During the evaporation of a liquid,

1 The enthalpy decreases
2 The enthalpy increases
3 The enthalpy remains unchanged
4 The internal energy decreases
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CHXI06:THERMODYNAMICS

369517 In which of the following exothermic reactions, the heat liberated per mole is the highest?

1 \(\mathrm{\mathrm{CaO}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{Ca}(\mathrm{OH})_{2}}\)
2 \(\mathrm{\mathrm{SrO}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{Sr}(\mathrm{OH})_{2}}\)
3 \(\mathrm{\mathrm{BaO}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{Ba}(\mathrm{OH})_{2}}\)
4 \(\mathrm{\mathrm{MgO}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{Mg}(\mathrm{OH})_{2}}\)
JEE - 2013
CHXI06:THERMODYNAMICS

369518 Consider the following reaction between zinc and oxygen and choose the correct options out of the options given below :
\(\rm{2 \mathrm{Zn}_{(s)}+O_{2(g)} \rightarrow 2 \mathrm{ZnO}_{(s)} ; \Delta H=-693.8 \mathrm{~kJ} / \mathrm{mol}}\)

1 The enthalpy of two moles of \(\mathrm{\mathrm{ZnO}}\) is less than the total enthalpy of two moles of \(\mathrm{\mathrm{Zn}}\) and one mole of oxygen by \(\mathrm{693.8 \mathrm{~kJ}}\).
2 The enthalpy of two moles of \(\mathrm{\mathrm{ZnO}}\) is more than the total enthalpy of two moles of \(\mathrm{\mathrm{Zn}}\) and one mole of oxygen by \(\mathrm{693.8 \mathrm{~kJ}}\).
3 \(\mathrm{598.3 \mathrm{~kJ} \mathrm{~mol}^{-1}}\) energy is evolved in the reaction.
4 \(\mathrm{693.8 \mathrm{~kJ} \mathrm{~mol}^{-1}}\) energy is absorbed in the reaction.
CHXI06:THERMODYNAMICS

369519 Consider the following statements for the given reactions:
(I) \(\mathrm{\dfrac{1}{2} \mathrm{~N}_{2}(\mathrm{~g})+\dfrac{1}{2} \mathrm{O}_{2}(\mathrm{~g}) \rightarrow \mathrm{NO}(\mathrm{g})}\);
\(\rm{\Delta_{\mathrm{r}} \mathrm{H}^{\mathrm{o}}=90 \mathrm{kJmol}^{-1}}\)
(II) \(\mathrm{\mathrm{NO}(\mathrm{g})+\dfrac{1}{2} \mathrm{O}_{2}(\mathrm{~g}) \rightarrow \mathrm{NO}_{2}(\mathrm{~g})}\);
\(\rm{\Delta_{\mathrm{r}} \mathrm{H}^{\circ}=-74 \mathrm{kJmol}^{-1}}\)
I.
In reaction (I), \(\mathrm{N O(g)}\) is unstable because the energy is released and unstable \(\mathrm{\mathrm{NO}(\mathrm{g})}\) changes into the stable \(\mathrm{\mathrm{NO}_{2}(\mathrm{~g})}\).
(II) The energy is absorbed in reaction (i) , \(\mathrm{\mathrm{NO}(\mathrm{g})}\) is unstable and unstable \(\mathrm{\mathrm{NO}(\mathrm{g})}\) changes into the stable \(\mathrm{\mathrm{NO}_{2}(\mathrm{~g})}\).
Select the correct statements and choose the correct option

1 Only I
2 Only II
3 Both I and II
4 None of these
CHXI06:THERMODYNAMICS

369520 During the evaporation of a liquid,

1 The enthalpy decreases
2 The enthalpy increases
3 The enthalpy remains unchanged
4 The internal energy decreases
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CHXI06:THERMODYNAMICS

369517 In which of the following exothermic reactions, the heat liberated per mole is the highest?

1 \(\mathrm{\mathrm{CaO}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{Ca}(\mathrm{OH})_{2}}\)
2 \(\mathrm{\mathrm{SrO}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{Sr}(\mathrm{OH})_{2}}\)
3 \(\mathrm{\mathrm{BaO}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{Ba}(\mathrm{OH})_{2}}\)
4 \(\mathrm{\mathrm{MgO}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{Mg}(\mathrm{OH})_{2}}\)
JEE - 2013
CHXI06:THERMODYNAMICS

369518 Consider the following reaction between zinc and oxygen and choose the correct options out of the options given below :
\(\rm{2 \mathrm{Zn}_{(s)}+O_{2(g)} \rightarrow 2 \mathrm{ZnO}_{(s)} ; \Delta H=-693.8 \mathrm{~kJ} / \mathrm{mol}}\)

1 The enthalpy of two moles of \(\mathrm{\mathrm{ZnO}}\) is less than the total enthalpy of two moles of \(\mathrm{\mathrm{Zn}}\) and one mole of oxygen by \(\mathrm{693.8 \mathrm{~kJ}}\).
2 The enthalpy of two moles of \(\mathrm{\mathrm{ZnO}}\) is more than the total enthalpy of two moles of \(\mathrm{\mathrm{Zn}}\) and one mole of oxygen by \(\mathrm{693.8 \mathrm{~kJ}}\).
3 \(\mathrm{598.3 \mathrm{~kJ} \mathrm{~mol}^{-1}}\) energy is evolved in the reaction.
4 \(\mathrm{693.8 \mathrm{~kJ} \mathrm{~mol}^{-1}}\) energy is absorbed in the reaction.
CHXI06:THERMODYNAMICS

369519 Consider the following statements for the given reactions:
(I) \(\mathrm{\dfrac{1}{2} \mathrm{~N}_{2}(\mathrm{~g})+\dfrac{1}{2} \mathrm{O}_{2}(\mathrm{~g}) \rightarrow \mathrm{NO}(\mathrm{g})}\);
\(\rm{\Delta_{\mathrm{r}} \mathrm{H}^{\mathrm{o}}=90 \mathrm{kJmol}^{-1}}\)
(II) \(\mathrm{\mathrm{NO}(\mathrm{g})+\dfrac{1}{2} \mathrm{O}_{2}(\mathrm{~g}) \rightarrow \mathrm{NO}_{2}(\mathrm{~g})}\);
\(\rm{\Delta_{\mathrm{r}} \mathrm{H}^{\circ}=-74 \mathrm{kJmol}^{-1}}\)
I.
In reaction (I), \(\mathrm{N O(g)}\) is unstable because the energy is released and unstable \(\mathrm{\mathrm{NO}(\mathrm{g})}\) changes into the stable \(\mathrm{\mathrm{NO}_{2}(\mathrm{~g})}\).
(II) The energy is absorbed in reaction (i) , \(\mathrm{\mathrm{NO}(\mathrm{g})}\) is unstable and unstable \(\mathrm{\mathrm{NO}(\mathrm{g})}\) changes into the stable \(\mathrm{\mathrm{NO}_{2}(\mathrm{~g})}\).
Select the correct statements and choose the correct option

1 Only I
2 Only II
3 Both I and II
4 None of these
CHXI06:THERMODYNAMICS

369520 During the evaporation of a liquid,

1 The enthalpy decreases
2 The enthalpy increases
3 The enthalpy remains unchanged
4 The internal energy decreases
For More Updates join with Us
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