Question

(a) How many milliliters of 0.165 M HCl are needed to neutralize completely 25.0 mL of 0.101 M Ba(OH)2 solution? 30.6 Correct: Your answer is correct. ml (b) How many milliliters of 3.50 M H2SO4 are needed to neutralize 25.0 g of NaOH? Incorrect: Your answer is incorrect. mL (c) If 54.8 mL of BaCl2 solution is needed to precipitate all the sulfate in a 544 mg sample of Na2SO4 (forming BaSO4), what is the molarity of the solution? Incorrect: Your answer is incorrect. M (d) If 27.5 mL of 0.125 M HCl solution is needed to neutralize a solution of Ca(OH)2, how many grams of Ca(OH)2 must be in the solution? Incorrect: Your answer is incorrect. g

Answer 1

a)

Using M1V1 = M2V2 formula

From the balanced equation

2HCl + Ba(OH)2 ---> 2H2O + BaCl2

So

M1 V1 = 2 x M2V2

0.165(V1) = 2 x 0.101 (25)

V1 = 5.05/0.165

V1 = 30.6 mL

b)

Given mass of NaOH = 25.0 g

Molar mass f NaOH = 40 g/mol

First we have to find moles of NaOH =

25g x (1 mol/40 g ) = 0.625 mol

H2SO4 + 2 NaOH ---> Na2SO4 + 2H2O

Moles of H2SO4 will neutralize 0.625 mol NaOH =