1. write the balanced chemical equation and the kₑ expression for the following reactions or processes that…

1. write the balanced chemical equation and the kₑ expression for the following reactions or processes that occur in water:\na. copper metal reacts in a solution of silver ions to produce a blue solution of copper(ii) ions and silver metal.\nb. when added to water, ammonia will undergo hydrolysis to form the ammonium cation and hydroxide anion.\nc. lead metal will react in a solution of chromium(iii) ions to form lead(ii) ions and chromium (ii) ions.\nd. only a small amount of barium carbonate will dissolve in water.

1. write the balanced chemical equation and the kₑ expression for the following reactions or processes that occur in water:\na. copper metal reacts in a solution of silver ions to produce a blue solution of copper(ii) ions and silver metal.\nb. when added to water, ammonia will undergo hydrolysis to form the ammonium cation and hydroxide anion.\nc. lead metal will react in a solution of chromium(iii) ions to form lead(ii) ions and chromium (ii) ions.\nd. only a small amount of barium carbonate will dissolve in water.

Answer

Explanation:

Step1: Write balanced equation for a

Copper (Cu) reacts with silver ions ($Ag^+$) to form copper(II) ions ($Cu^{2 +}$) and silver (Ag). Balance by electrons: $$Cu(s)+2Ag^+(aq)\rightleftharpoons Cu^{2 +}(aq)+2Ag(s)$$

Step2: Write $K_c$ expression for a

The $K_c$ expression for a reaction $aA + bB\rightleftharpoons cC + dD$ is $K_c=\frac{[C]^c[D]^d}{[A]^a[B]^b}$. Solids are not included in $K_c$ expressions. So for the above reaction, $K_c=\frac{[Cu^{2 +}]}{[Ag^+]^2}$

Step3: Write balanced equation for b

Ammonia ($NH_3$) reacts with water ($H_2O$) to form ammonium ion ($NH_4^+$) and hydroxide ion ($OH^-$). $$NH_3(aq)+H_2O(l)\rightleftharpoons NH_4^+(aq)+OH^-(aq)$$

Step4: Write $K_c$ expression for b

Since water is a pure liquid and not included in the $K_c$ expression, $K_c = [NH_4^+][OH^-]/[NH_3]$

Step5: Write balanced equation for c

Lead (Pb) reacts with chromium(III) ions ($Cr^{3+}$) to form lead(II) ions ($Pb^{2+}$) and chromium(II) ions ($Cr^{2+}$). Balance by electrons: $$3Pb(s)+2Cr^{3+}(aq)\rightleftharpoons 3Pb^{2+}(aq)+2Cr^{2+}(aq)$$

Step6: Write $K_c$ expression for c

Solids are excluded from $K_c$ expressions. So $K_c=\frac{[Pb^{2+}]^3[Cr^{2+}]^2}{[Cr^{3+}]^2}$

Step7: Write balanced equation for d

Barium carbonate ($BaCO_3$) dissolves in water to form barium ions ($Ba^{2+}$) and carbonate ions ($CO_3^{2 -}$). $$BaCO_3(s)\rightleftharpoons Ba^{2+}(aq)+CO_3^{2 -}(aq)$$

Step8: Write $K_c$ expression for d

Excluding the solid, $K_c=[Ba^{2+}][CO_3^{2 -}]$

Answer:

a. Balanced equation: $Cu(s)+2Ag^+(aq)\rightleftharpoons Cu^{2 +}(aq)+2Ag(s)$; $K_c=\frac{[Cu^{2 +}]}{[Ag^+]^2}$ b. Balanced equation: $NH_3(aq)+H_2O(l)\rightleftharpoons NH_4^+(aq)+OH^-(aq)$; $K_c = \frac{[NH_4^+][OH^-]}{[NH_3]}$ c. Balanced equation: $3Pb(s)+2Cr^{3+}(aq)\rightleftharpoons 3Pb^{2+}(aq)+2Cr^{2+}(aq)$; $K_c=\frac{[Pb^{2+}]^3[Cr^{2+}]^2}{[Cr^{3+}]^2}$ d. Balanced equation: $BaCO_3(s)\rightleftharpoons Ba^{2+}(aq)+CO_3^{2 -}(aq)$; $K_c=[Ba^{2+}][CO_3^{2 -}]$