A solution of hydrochloric acid is .9894 molar. When acid is used to titrate 25mL of a sodium hydroxide solution of unknown concentration to the phenolphthalein endpoint, 37.55mL of the acid are required. Calculate the molarity of the unknown sodium hydroxide solution?
2007-07-12 05:45:49 · 3 answers · asked by ... 3 in Science & Mathematics ➔ Chemistry
Moles HCl in 37.55 mL = 0.9894 x 37.55 / 1000 =
0.03715 = moles OH-
M ( NaOH ) 0.03715 / 0.0250 L = 1.486 M
2007-07-12 05:52:18 · answer #1 · answered by Dr.A 7 · 0⤊ 0⤋
HCl and NaOH are in the one-to-one ratio , so find the moles of the HCl by multiplying molarity by volume (in Litres)
whatever .9894 times .025 is. .. divide that by .03755 and you get the moles of the NaOH
if you want the molarity of the NaOH before or after the titration, then divide by the appropriate volume in Litres.
2007-07-12 05:58:20 · answer #2 · answered by Anonymous · 0⤊ 0⤋
37.55*.9894/25
2007-07-12 06:03:43 · answer #3 · answered by ag_iitkgp 7 · 0⤊ 1⤋