For a 1 molal aqueous NaCl solution, the mean ionic activity coefficient $\left(\gamma_{ \pm}\right)$and the Deby-Huckel Limiting Law constant (A) are related as
(a)$\log \gamma_{ \pm}=\sqrt{2} \mathrm{A}$
(b)$\log \gamma_{ \pm}=-\sqrt{2} \mathrm{A}$
(c)$\gamma_{ \pm}=10^{\mathrm{A}}$
(d)$\gamma_{ \pm}=10^{-\mathrm{A}}$
Answer
Answer: D ✓ checked by 4AB · confidence high
The source book printed A; on checking, D is correct — see the explanation.
Explanation
log γ± = −A|z₊z₋|√I. For 1 m NaCl, I = 1, so log γ± = −A and γ± = 10^(−A) (d).