JEE CHEMISTRY MCQ: THERMODYNAMICS

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Application +4 | -1

The dissolution of

{CaCl}_2 \cdot 6 {H}_2 {O}

in a large volume of water is endothermic to the extent of

3.5 \mathrm{~kcal/mol}.

For the reaction,

{CaCl}_2(\mathrm{s})+6 {H}_2 {O}({l}) \rightarrow{CaCl}_2 \cdot 6 {H}_2 {O}(\mathrm{s}) ; \Delta H

-23.2 \mathrm{~kcal}.

The heat of solution of anhydrous

{CaCl}_2

in large quantity of water will be

View answer and explanation

Correct option: B

-19.7 \mathrm{~kcal} \mathrm{~mol}^{-1}

The correct answer is B (-19.7 kcal mol⁻¹) because it is calculated by using Hess's law to relate the enthalpy changes of the given reactions.

More Questions from THERMODYNAMICS

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\ \mathrm{C}(\mathrm{s})+\frac{1}{2} \mathrm{O}_2(\mathrm{~g})-\mathrm{CO}(\mathrm{g}), \Delta \mathrm{H}_1=\mathrm{a}

\mathrm{CO}(\mathrm{g})+\frac{1}{2} \mathrm{O}_2(\mathrm{~g})-\mathrm{CO}_2(\mathrm{~g}), \Delta \mathrm{H}_2=\mathrm{b}

\mathrm{C}(\mathrm{s})+\mathrm{CO}_2(\mathrm{~g})-2 \mathrm{CO}(\mathrm{g}) ; \Delta \mathrm{H}_3=\mathrm{c}

0.18 \mathrm{~g}

4 \mathrm{~K}.

\left(\Delta_{\mathrm{C}} \text{H}^{\circ}=-2.8\times 10^6 \mathrm{~J} / \mathrm{mol} \text{ glucose}\right)

{CsI}

{CsCl}

{CsCl}

{Cs} I

\begin{array}{cccccccccccccccccccc} {}&{\Delta H(KJ/mol)} \\ {1/2A \to B}&{ + 150} \\ {3B \to 2C + D}&{ - 125} \\ {E + A \to 2D}&{ + 350} \end{array}

{B}+{D} \rightarrow {E}+2 {C}, \Delta {H}

\Delta H

\Delta u

\mathrm{C}{\mathrm{H}_4}\left( \mathrm{g} \right) + 2{\mathrm{O}_2}\left( \mathrm{g} \right) \to \mathrm{C}{\mathrm{O}_2}\left( \mathrm{g} \right) + {\mathrm{H}_2}\mathrm{O}\left( l \right);\Delta H = - 890.3\mathrm{kJ}