Question

49.7 mL of a solution of NaOH is needed to neutralize a solution that contains 1.86 g of H2504 in 20.00 mL of water. What is the molarity of the NaOH solution?
H2SO4 + 2 NaOH --> 2H2O + Na2SO4

1) 0.763 M
2) 0.0404 M
3) 1.13 M
4) 0.481 M
5) 0.602 M
6) 2.23 M
7) 1.81 M
8) 2.94 M

Answer 1

Answer:

1) C NaOH = 0.763 M

Explanation:

• H2SO4 + 2 NaOH → 2 H2O + Na2SO4

∴ V NaOH = 49.7 mL = 0.0497 L

∴ m H2SO4 = 1.86 g

∴ V sln = 20.00 ml = 0.020 L

∴ Mw H2SO4 = 98.079 g/mol

⇒ n H2SO4 = (1.86 g)(mol / 98.079 g) = 0.019 mol H2SO4

⇒ n NaOH = (0.019 mol H2SO4)(2 mol NaOH/ mol H2SO4) = 0.038 mol NaOH

⇒ C NaOH = 0.038 mol / 0.0497 L = 0.763 M