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Soaring Crane
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1. A bottle of strong monoprotic acid was labelled as having a concentration of 2.040 x 10-1 mol/L. Given that KW = 1.00 x 10-14, determine the p0H of the acid solution.
[H3O+][OH-]= K_w
[OH-] = k_W/[H3O+] = (1.00*10^-14)/(2.040*10^-1 M) = 4.90196078E-14
-log[OH-] = pOH
-log[4.90196E-14] = pOH = 13.3096 = 13.3
2. The pH of a 0.2700 molar solution of unknown monoprotic acid was measured and found to be 5.75. Calculate the Ka of this acid.
pH = -log[H3O+]
5.75 = -log[H3O+]
antilog[-5.75] = [H3O+] = 0.000001778 = X
K_A = [H3O+][A-]/[HA] = X^2/[0.2700 - X] = (0.000001778)/(0.2700 - 0.000001778) = 1.17122166E-11 = 1.17E-11
Thanks.
[H3O+][OH-]= K_w
[OH-] = k_W/[H3O+] = (1.00*10^-14)/(2.040*10^-1 M) = 4.90196078E-14
-log[OH-] = pOH
-log[4.90196E-14] = pOH = 13.3096 = 13.3
2. The pH of a 0.2700 molar solution of unknown monoprotic acid was measured and found to be 5.75. Calculate the Ka of this acid.
pH = -log[H3O+]
5.75 = -log[H3O+]
antilog[-5.75] = [H3O+] = 0.000001778 = X
K_A = [H3O+][A-]/[HA] = X^2/[0.2700 - X] = (0.000001778)/(0.2700 - 0.000001778) = 1.17122166E-11 = 1.17E-11
Thanks.
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