Question
Write an expression for $\mathrm{K}_{\mathrm{a}}$, for ionisation of HCN in aqueous solution. Give equation also.
✓
Answer
$\text{HCN}+\text{H}_2\text{O}\rightleftharpoons\text{H}_3\text{O}^{\oplus}+\text{CN}^-$$\text{K}_{\text{a}}=\frac{[\text{H}_3\text{O}^+][\text{CN}^-]}{[\text{HCN}]}$
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
$\text{E}^\circ_\frac{\text{Zn}^{2+}}{\text{Zn}}=-0.76\text{V}$
$\text{E}^\circ_\frac{\text{Cr}^{2+}}{\text{Cr}}=-0.74$
$\text{E}^\circ_\frac{\text{H}^+}{\text{H}_2}=0$
$\text{E}^\circ_\frac{\text{Fe}^{3+}}{\text{Fe}^{3+}}=0.77\text{V}$
Which is the strongest oxidising agent out of them?
→$\text{E}^\circ_\frac{\text{Cr}^{2+}}{\text{Cr}}=-0.74$
$\text{E}^\circ_\frac{\text{H}^+}{\text{H}_2}=0$
$\text{E}^\circ_\frac{\text{Fe}^{3+}}{\text{Fe}^{3+}}=0.77\text{V}$
Which is the strongest oxidising agent out of them?
Name the compounds whose line formulae are given below.
Calculate the free energy change when 1 mole of NaCl is dissolved in water at 298 K . (Given, lattice energy of $\mathrm{NaCl}=$ $-777.8 \mathrm{~kJ} \mathrm{~mol}^{-1}$, hydration energy $=-774.1 \mathrm{~kJ} \mathrm{~mol}^{-1}$ and $\Delta \mathrm{S}=0.043 \mathrm{~kJ} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}$ at 298 K ).
→Calculate the temperature above which the reduction of lead oxide in the following reaction becomes spontaneous:
PbO(s) + C(s) → Pb(s) + CO(g)
Given: $[\Delta\text{H}=108.4\text{kJ mol}^{-1};\ \Delta\text{S}=190\text{J K}^{-1}\text{mol}^{-1}]$
→PbO(s) + C(s) → Pb(s) + CO(g)
Given: $[\Delta\text{H}=108.4\text{kJ mol}^{-1};\ \Delta\text{S}=190\text{J K}^{-1}\text{mol}^{-1}]$
What do you meant by homologous series? Explain with example.
On the basis of VSEPR theory, predict the shapes of the following molecules and ions:
→- $\text{PH}_3$
- $\text{NH}_3$
- $\text{NH}^-_2$
- $\text{H}_3\text{O}^+$
Give the common name of:
- Methanol olido.
- Ethanol.
- Ethoxyethane.
- Ethanoic acid.
- 1, 4-dimethyl benzene.
Given that the enthalpy of formation of $\mathrm{H}_2 \mathrm{O}$ is $-68 \mathrm{kcal} / \mathrm{mol}$. Calculate the enthalpy of formation of OH ions.
→Give four differences between 3p and 4p subshell.
Use the following data to calculate the $\text{K}_{\text{sp}}$ value for Agl(s)$\text{H}_{2}\text{(g)} + \text{Cl}_{2} \text{(g)} \rightleftharpoons\text{2HCl(g)}$
$\Delta\text{H}^{\circ} = -92\text{kJ}, \ \Delta\text{S}^{\circ} = -95\text{JK}^{-1}$
→$\Delta\text{H}^{\circ} = -92\text{kJ}, \ \Delta\text{S}^{\circ} = -95\text{JK}^{-1}$