Question 8 • 26-27 - C - RUSD Chemistry in the Earth System
For dissolving RbI, reverse the lattice-formation step, so its contribution is −(−630.0) = +630.0 kJ/mol. The total is 31.0 = 630.0 + (−315.0) + ΔHhydr(I⁻), giving ΔHhydr(I⁻) = −284.0 kJ/mol. This matches choice C, −284.0 kJ/mol.
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