Question

how many mL of a 0.20 M solution of HCl are needed to make 500 mL of a pH 2.00

Answer 1

Answer:-

The answer is given in the image,

HCl is a strong acid and dissociate completely So [HCl] = [H^+] P^h = 2.00 PH = -log [H^+] [H^+] = 10^- PH [H^+] = 10 ^- 2.00 [H^+] = 0.010 M So [HCl] = 0.010 M = M_2 Volume [V_2] = 500 mL Given [HCl] = 0.20 M = M_L Let V_1 volume is needed then from dilution equation M_1 V_1 = m_2 V_2 V_1 = M_2 V_2/M_1 V_1 = 0.010 times 500/0.20 V_L = 25 mL So 25 mL of a 0.20 M Solution of HCl are needed