Question

Hydroxide ions Homework • Unanswered Estimate the molar concentration of hydroxide ions OH in vinegar. Enter your answer using this type of scientific notation: X.XEY Numeric Answer:

just the first question about the OH-, included second photo for question info

Answer 1

CH₃COOH (AcOH) dissociates as

CH₃COOH + H₂O  $\rightleftharpoons$  CH₃COO^- + H₃O⁺

ICE table is

	ACOH	ACO-	H3O+
I	C	--	-
C	-C$\alpha$	+C$\alpha$	+C$\alpha$
E	C- C$\alpha$	C$\alpha$	C$\alpha$

$\alpha$ is degree of dissociation.

given, degree of dissociation ($\alpha$) = (4/1000) = 0.004

Concenteation of acetic acid (C) = 1 M

[H₃O⁺] = c$\alpha$ = 1× 0.004 = 0.004 M = 4 × 10^-3 M

At 25⁰c;

[H₃O⁺] × [OH^-] = K_w = 10^-14

or, [OH^-] = 10^-14/(4×10^-3) = 2.5 ×10^-12 M.