Determine the pH of each solution. a. 0.0100 M HClO₄ b. 0.115 M HClO₂ c. 0.045 M Sr(OH)₂ d. 0.0852 M KCN e. 0.155 M NH₄Cl

Verified step by step guidance

1. Step 1: Identify the nature of each compound in the solutions. HClO_4 is a strong acid, HClO_2 is a weak acid, Sr(OH)_2 is a strong base, KCN is a salt that can form a basic solution, and NH_4Cl is a salt that can form an acidic solution.
2. Step 2: For the strong acid HClO_4, calculate the pH directly from its concentration. Since it dissociates completely, [H^+] = 0.0100 M. Use the formula pH = -log[H^+].
3. Step 3: For the weak acid HClO_2, use the acid dissociation constant (K_a) to find [H^+]. Set up the equilibrium expression for the dissociation of HClO_2 and solve for [H^+]. Then, calculate the pH using pH = -log[H^+].
4. Step 4: For the strong base Sr(OH)_2, calculate the pOH first. Since Sr(OH)_2 dissociates completely and provides 2 OH^- ions per formula unit, [OH^-] = 2 * 0.045 M. Use pOH = -log[OH^-] and then find pH using pH = 14 - pOH.
5. Step 5: For the salts KCN and NH_4Cl, determine the pH by considering the hydrolysis of the ions. For KCN, CN^- will hydrolyze to form OH^-, making the solution basic. For NH_4Cl, NH_4^+ will hydrolyze to form H^+, making the solution acidic. Use the appropriate equilibrium expressions and constants (K_b for CN^- and K_a for NH_4^+) to find the pH.