The values of Delta G_f^o (in kJ mol^{-1}) f | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(A) The dissociation reaction is: $Mg(OH)_{2(s)} 	o Mg^{2+}_{(aq)} + 2OH^-_{(aq)}$Calculate the standard Gibbs free energy change $(\Delta G^o)$:$\De

Vedclass · Accepted Answer

$8.4 	imes 10^{-12} \ M^3$

Vedclass · Answer

(A) The dissociation reaction is: $Mg(OH)_{2(s)} 	o Mg^{2+}_{(aq)} + 2OH^-_{(aq)}$Calculate the standard Gibbs free energy change $(\Delta G^o)$:$\Delta G^o = [\Delta G_f^o(Mg^{2+}) + 2 	imes \Delta G_f^o(OH^-)] - [\Delta G_f^o(Mg(OH)_2)]$$\Delta G^o = [-456.0 + 2(-157.3)] - (-833.9)$$\Delta G^o = [-456.0 - 314.6] + 833.9 = 63.3 \ kJ \ mol^{-1} = 63300 \ J \ mol^{-1}$Using the relation $\Delta G^o = -RT \ln K_{sp}$ or $\Delta G^o = -2.303 RT \log K_{sp}$:$63300 = -2.303 	imes 8.314 	imes 298 	imes \log K_{sp}$$63300 = -5705.85 	imes \log K_{sp}$$\log K_{sp} = -11.0938$$K_{sp} = 10^{-11.0938} \approx 8.06 	imes 10^{-12} \ M^3$Rounding to the nearest provided option,the correct answer is $8.4 	imes 10^{-12} \ M^3$.

The values of $\Delta G_f^o$ (in $kJ \ mol^{-1}$) for $Mg(OH)_2$ at $25 \ ^oC$ are given below. Calculate the solubility product constant $(K_{sp})$.
$Mg^{2+}_{(aq)} = -456.0; OH^{-}_{(aq)} = -157.3; Mg(OH)_{2(s)} = -833.9$

Similar Questions

Assign $A$,$B$,$C$,$D$ from the given type of reaction.
$Ba(AcO)_2 + K_2CrO_4 \longrightarrow BaCrO_4 \downarrow + 2AcOK$

The $pH$ at which $Mg(OH)_2$ $[K_{sp} = 1 \times 10^{-11}]$ begins to precipitate from a solution containing $0.10 \ M$ $Mg^{2+}$ ions is . . . . . .

At $298 \ K$ temperature,the $K_{sp}$ of $Mg(OH)_2$ is $1.8 \times 10^{-11}$. If $0.1 \ M$ $NaOH$ solution is added to it,what is the concentration of $Mg^{2+}$ ions? Calculate its solubility in water.

Assign $A, B, C, D$ from the given type of reaction: $PbCl_2(s) + \text{Hot water} \longrightarrow Pb^{2+}(aq) + 2Cl^{-}(aq)$

$A$ salt $MX$ has $K_{sp} = 4 \times 10^{-10}$. What value of $K_{sp}$ must another salt $MX_3$ have if the molar solubility of the two salts is to be identical?

Vedclass Test Series

Exam Paper Generator

Online Exam Module

The values of $\Delta G_f^o$ (in $kJ \ mol^{-1}$) for $Mg(OH)_2$ at $25 \ ^oC$ are given below. Calculate the solubility product constant $(K_{sp})$.$Mg^{2+}_{(aq)} = -456.0; OH^{-}_{(aq)} = -157.3; Mg(OH)_{2(s)} = -833.9$