Question

What is the concentration of an NaOH solution that requires 20.0 ml of a 1.35 M H₂SO₄ solution to neutralize 18.0 ml of NaOH?

A. 0.750 M
B. 1.22 M
C. 1.50 M
D. 3.00 M

Answer 1

In a neutralization reaction, the moles of acid are equal to the moles of base at the equivalence point. To find the concentration of the NaOH solution, we can use the molar ratio between NaOH and H₂SO₄. By calculating the moles of H₂SO₄ and then using the molarity equation, we find that the concentration of the NaOH solution is c. 1.50 M.

Step-by-step explanation:

In a neutralization reaction, the moles of acid are equal to the moles of base at the equivalence point. We can use this concept to find the concentration of the NaOH solution. From the balanced equation:

2 NaOH + H₂SO₄ → Na₂SO₄ + 2 H₂O

The molar ratio is 2:1, which means that 2 moles of NaOH react with 1 mole of H₂SO₄.

Given: 20.0 mL of 1.35 M H₂SO₄

We can use the Molarity equation to find the moles of H₂SO₄:

Moles of H₂SO₄ = (Molarity of H₂SO₄) x (Volume of H₂SO₄ in L)

Moles of H₂SO₄ = (1.35 M) x (0.0200 L) = 0.0270 mol

Since the molar ratio is 2:1, the moles of NaOH will also be 0.0270 mol.

To find the concentration of the NaOH solution, we use the Molarity equation:

Molarity of NaOH = (Moles of NaOH) / (Volume of NaOH in L)

Molarity of NaOH = (0.0270 mol) / (0.0180 L) = 1.50 M

The concentration of the NaOH solution is therefore 1.50 M, which corresponds to option C.