Download App

5. Thermodynamics and thermochemistry — Chemistry STD 11 Science — Question

Gujarat BoardEnglish MediumSTD 11 ScienceChemistry5. Thermodynamics and thermochemistry1 Mark
MCQ
The lattice energy of $NaCl$ is $-780\, kJ\, mol^{-1}$. The enthalpies of hydration of $Na_{\left( g \right)}^ + $ and $Cl_{\left( g \right)}^ - $ ions are $-406\, kJ\, mol^{-1}$ and $-364\, kJ\, mol^{-1}$. The enthalpy of solution of $NaCl_{(s)}$ is.....$kJ\, mol\,^{-1}$
  • A
    $738$
  • ✓
    $10$
  • C
    $-10$
  • D
    $-822$
✓

Answer

Correct option: B.
$10$
b
$\mathrm{NaCl}(\mathrm{s}) \rightarrow \mathrm{Na}^{+}(\mathrm{g})+\mathrm{Cl}^{-}(\mathrm{g}) ; \Delta \mathrm{H}_{1} =780 \,\mathrm{KJ} $

$ \mathrm{Na}^{+}(\mathrm{g})+\mathrm{aq} \rightarrow \mathrm{Na}^{+}(\mathrm{aq})  \Delta \mathrm{H}_{2}=-406 \,\mathrm{KJ} $

$ \mathrm{Cl}^{-}(\mathrm{g})+\mathrm{aq} \rightarrow \mathrm{Cl}^{-}(\mathrm{aq})  \Delta \mathrm{H}_{3}=-364 \,\mathrm{KJ} $

$ \mathrm{NaCl}(\mathrm{s})+\mathrm{aq} \rightarrow \mathrm{Na}^{+}(\mathrm{aq})+\mathrm{Cl}^{-}(\mathrm{aq}) $

$ \Delta \mathrm{H}=\Delta \mathrm{H}_{1}+\Delta \mathrm{H}_{2}+\Delta \mathrm{H}_{3}$

$= 780-406-364 $

$=10 \,\mathrm{KJ\,mol}^{-1} $

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "M.C.Q (1 Marks)" from 5. Thermodynamics and thermochemistry→5. Thermodynamics and thermochemistry — all question types→Chemistry STD 11 Science question papers→Gujarat Board STD 11 Science question papers→Gujarat Board question paper generator→

Similar questions

Which is the correct order of the first ionization potential of $N, O$ and $C$
→
Which one of the following is an example of disproportionation reaction?
→
Propionic acid is subjected to reduction with hydroiodic acid in the presence of a little P, the product formed is
→
The number of orbitals in the fourth principal quantum number will be
→
Which element has maximum electron affinity
→
One mole of a symmetrical alkene on ozonolysis gives two moles of an aldehyde having a molecular mass of $44\, u.$ The alkene is
→
Nitrolim is a:
→
Which of the following species have maximum number of unpaired electrons
→
Which of the following molecule has a planar structure ?
→
If $A$ to $E$ are element of a group from top to bottom then group can be
→