Question

1. Write the net ionic equation for the reaction that occurs when equal volumes of 0.256 M aqueous hypochlorous acid and sodium fluoride are mixed (there should be 2 spots before and after arrows)

at equilibrium is it product or react favored

and is the ph <, =, or > than 7?

2. Write the balanced NET IONIC equation for the reaction that occurs when hydrochloric acid and potassium cyanide are combined. (there should be 2 spots on both sides of arrows)

Also, is the reaction classified as: strong acid + strong base, weak acid + strong base, strong acid + weak base, or weak acid + weak base?

The extent of this reaction is: below 50, 50, above 50, or 100%?

3. Write the balanced net ionic equation for he reaction that occurs when acetic acid and barium hydroxide are combined. (2 on the left and 3 spots on the right of arrows)

Also, is the reaction classified as: strong acid + strong base, weak acid + strong base, strong acid + weak base, or weak acid + weak base?

The extent of this reaction is: below 50, 50, above 50, or 100%?

Answer 1

Sol:-

Chemical equation is :-

HClO (aq)    +    NaF (aq) <------------> NaClO (aq)   + HF (aq)

HClO and HF are weak acids i.e weak electrolytes and we know weak electrolytes do not completely dissociated into its ions in aqueous solution .

NaF and NaClO are strong electrolytes and strong electrolytes are completely dissociated into its ions in aqueous solution.

therefore Ionic equation is :-

HClO (aq)   +   Na⁺ (aq) +   F^-(aq) <--------------> Na⁺(aq)    +    ClO^- (aq)   + HF (aq)

and Net ionic equation after the cancellation of Na⁺ (aq) on both side is :-

HClO (aq)   +   F^-(aq) <--------------> ClO^- (aq)   + HF (aq)

K_a value of HF = 6.6 x 10^-4 and

K_a value of HClO = 2.9 x 10^-8

K_a of HF > K_a of HClO therefore HF is stronger acid than HClO and hence equilibrium will shifts in backward direction i.e reactant side . backward reaction forms acidic buffer solution in which HF act as weak acid while F^- act as its conjugate base therefore pH of the solution will be acidic i.e pH < 7 and exact pH value of acidic buffer solution can be calculated by using Henderson-Hasselbalch equation .