Chemistry - Thermochemistry Question with Solution | TestHub

P: ${\mathrm{MgCl}}_2(\mathrm{s})\to {\mathrm{Mg}}^{2+}(\mathrm{g})+2{\mathrm{Cl}}^{-}(\mathrm{g})$ represents lattice enthalpy (2).

Q: ${\mathrm{MgCl}}_2(\mathrm{s})\to {\mathrm{Mg}}^{2+}(\mathrm{aq})+2{\mathrm{Cl}}^{-}(\mathrm{aq})$ represents enthalpy of solution (4).

R: ${\mathrm{MgCl}}_2(\mathrm{s})\to \mathrm{Mg}(\mathrm{g})+2\mathrm{Cl}(\mathrm{g})$ represents enthalpy of atomisation (5).

S: $\mathrm{Mg}(\mathrm{s})\to {\mathrm{Mg}}^{2+}(\mathrm{g})$ represents enthalpy of atomisation + enthalpy of ionisation (3).

Therefore, the correct match is P $\to$ 2, Q $\to$ 4, R $\to$ 5, S $\to$ 3.