How much 3.0M NaOH is needed to neutralize 30ml of 0.75M of H2SO4?

15mL

Explanation:

Step 1:

Data obtained from the question

This includes the following:

Molarity of the base (Mb) = 3M

Volume of base (Vb) =.?

Volume of acid (Va) = 30mL

Molarity of the acid (Ma) = 0.75M

Step 2:

The balanced equation for the reaction.

H2SO4 + 2NaOH —> Na2SO4 + 2H2O

From the balanced equation above,

The mole ratio of the acid (nA) = 1

The mole ratio of the base (nB) = 2

Step 3:

Determination of the volume of the base.

This can be achieved as follow:

MaVa/MbVb = nA /nB

0.75 x 30 / 3 x Vb = 1/2

Cross multiply

3 x Vb = 0.75 x 30 x 2

Divide both side by 2

Vb = (0.75 x 30 x 2) /3

Vb = 15mL

Therefore, the volume of the base needed is 15mL.