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Ch.16 - Acids and Bases
Chapter 16, Problem 79b,c,d

Find the pH of each mixture of acids. b. 0.150 M in HNO2 and 0.085 M in HNO3 c. 0.185 M in HCHO2 and 0.225 M in HC2H3O2 d. 0.050 M in acetic acid and 0.050 M in hydrocyanic acid

Verified step by step guidance
1
Step 1: Identify the acids in each mixture and determine their strengths. HNO_3 is a strong acid, while HNO_2, HCHO_2, HC_2H_3O_2, and hydrocyanic acid (HCN) are weak acids.
Step 2: For each mixture, calculate the contribution of the strong acid to the pH. Since strong acids dissociate completely, the concentration of H^+ ions from the strong acid is equal to its initial concentration.
Step 3: For the weak acids, use the acid dissociation constant (K_a) to calculate the concentration of H^+ ions. Set up an equilibrium expression for each weak acid: K_a = [H^+][A^-]/[HA].
Step 4: For each mixture, add the concentration of H^+ ions from the strong acid to the concentration of H^+ ions from the weak acids to find the total [H^+].
Step 5: Calculate the pH of each mixture using the formula pH = -log[H^+].