A chemist uses 0.25 L of 2.00 M H₂SO₄ to completely neutralize 2.00 L of a NaOH solution. The balanced chemical equation of the reaction is given below:

[tex]\[ 2 \text{NaOH} + \text{H}_2\text{SO}_4 \rightarrow \text{Na}_2\text{SO}_4 + 2 \text{H}_2\text{O} \][/tex]

What is the concentration of NaOH used?

A. 0.063 M
B. 0.25 M
C. 0.50 M
D. 1.0 M



Answer :

Sure, let's go through the problem step by step to find the concentration of NaOH used in the reaction.

1. Identify the Given Data:
- Volume of [tex]\( H_2SO_4 \)[/tex]: [tex]\(0.25 \, L \)[/tex]
- Concentration of [tex]\( H_2SO_4 \)[/tex]: [tex]\(2.00 \, M \)[/tex]
- Volume of [tex]\( NaOH \)[/tex]: [tex]\(2.00 \, L \)[/tex]

2. Chemical Reaction:
According to the balanced chemical equation:
[tex]\[ 2 \, NaOH + H_2SO_4 \rightarrow Na_2SO_4 + 2 \, H_2O \][/tex]

This shows that 1 mole of [tex]\( H_2SO_4 \)[/tex] neutralizes 2 moles of [tex]\( NaOH \)[/tex].

3. Calculate Moles of [tex]\( H_2SO_4 \)[/tex]:
Using the formula [tex]\( \text{moles} = \text{volume} \times \text{concentration} \)[/tex]:
[tex]\[ \text{Moles of } H_2SO_4 = 0.25 \, L \times 2.00 \, M = 0.5 \, \text{moles} \][/tex]

4. Determine Moles of [tex]\( NaOH \)[/tex] Required for Neutralization:
From the balanced equation, with a mole ratio of [tex]\( 2 \, NaOH : 1 \, H_2SO_4 \)[/tex]:
[tex]\[ \text{Moles of } NaOH = 2 \times \text{Moles of } H_2SO_4 = 2 \times 0.5 = 1.0 \, \text{moles} \][/tex]

5. Calculate Concentration of [tex]\( NaOH \)[/tex]:
Using the formula [tex]\( \text{concentration} = \frac{\text{moles}}{\text{volume}} \)[/tex]:
[tex]\[ \text{Concentration of } NaOH = \frac{1.0 \, \text{moles}}{2.0 \, L} = 0.5 \, M \][/tex]

Thus, the concentration of [tex]\( NaOH \)[/tex] used is [tex]\( 0.50 \, M \)[/tex].

So, the correct answer is:
[tex]\[ 0.50 \, M \][/tex]