Question

Acid base equalibria

Solution E is made by mixing 1o mL NaA stock solution. e. .H stk solution and 10 .c ml Calculate the [HA]o by dilution of the HA stock solution. Calculate (AJ, by dilution of the NaA stock solution. Calculate [H'Je from the pli. 53 25 From the stoichiometry calculate [A]eq and [HAI Using the values above, calculate K, for the weak acid HA. f. Solution F is made by mixing 2.00 mL HA stock solution and 2o oomL mL NaA stock solution. Measured pH 4R2 Calculate the [HAJo by dilution of the HA stock solution. Calculate [A o by dilution of the NaA stock solution. Calculate [HI'ly from the pHy.g21s xto From the stoichiometry calculate [A ley and [HAly Using the values above, calculate K, for the weak acid HA.

Answer 1

Answer:

e. Solution E is made by mixing 10.0 mL. HA stock solution mL NaA stock solution. Measured pli Calculate the [HAJ, by dilution of the HA stock solution.n By Dilution law, M2*V2 M1-v1 so, M2 M1-v1/V2 0.10 10.0/20.0-0.05 M - itially, M1 0.10 M, v1 10.0 mL. Finally, M2 ?, V2 20.0 mL Calculate [A']. by diltution of the M2-MIV1 /V20ially M1-01 M, V1 100mL Fially 2, v2- 20.0 mL Calculate [IrJeq from the pH., -Y53-2. 5x10 M2=M1"V1 / V2 = 0.1 * 10.0 CH11 lo From the stoichiometry calculate [AJey and [HAle- [A] [H] 2.95 x 10S M [HA 0.05-[H+] 0.05 (aapx) as [H+ <<<x 0.05 Using the values above, calculate K, for the weak acid HA. Ka = [H+] [A] / [HA] = (2.95* 10-5)((2.95 * 10-5) / 0.05:1.74 x 10-8. Ka 1.74 x 108. f. Solution F is made by mixing mlL HA stock solution and 2o oom mL NaA stock solution. Measured pH 422 Calculate the [HAJo by dilution of the HA stock solution. M2 M1 V1/v2-0.1.2.0/22.0- 0.009M [HAjintal 0.009 M Calculate [A'l by dilution of the NaA stock solution M2 = 0.1 * 20.0 / 22.0-0091 M Calculate [H'loy from the pH From the stoichiometry calculate [Al and [HAk [A-leq [H+] 1.5 x 10-s M [HA] 0.009 M 9aprx) Using the values above, calculate Ka for the weak acid HA. Ka (1.5*105)2/0.009 - Ka = 2.5 * 10-8.

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