A 0.110 M H_2SO_4 solution is used to neutralize 10.0 mL of 0.085 M NaOH. What volume of the acid, in mL, is required to neutralize the base?

1 Answer
Jan 25, 2017

You need 3.86 mL of "H"_2"SO"_4 to neutralise the base.

Explanation:

So what we have to do is use stoichiometry to find the volume of acid needed to neutralise the base.

1: We need a balanced chemical equation:

"H"_2"SO"_4(aq) + "2NaOH (aq)" rarr "Na"_2"SO"_4 (s) + "2H"_2"O"(l)

So what we can find first is the moles of "NaOH".

2: Solve for moles. Note that I changed 10 mL to 0.01 L.

n_1 = cv

= "0.085 mol/L (0.010 L)"

= 8.5xx10^-4 "mol"

3: Now we transfer the moles of "NaOH" to "H"_2"SO"_4".

To do that, we divide by "NaOH"'s coefficient, and multiply by "H"_2"SO"_4's.

n_2 = (8.5xx10^-4 "mol")/2

= 4.25xx10^-4 "mol"

There are 4.25xx10^-4 mol of "H"_2"SO"_4.

4: With "H"_2"SO"_4's moles and concentration (given), we can solve for volume.

v = n_"2"/c

= (4.25xx10^-4 "mol")/("0.110 mol/L")

"= 0.003,863,636" L = "3.863,636" mL

Significant digits tells us to round the volume to 3 decimal places:

3.86 mL.

Therefore, you need 3.86 mL of "H"_2"SO"_4 to neutralise the base.

Hope this helps :)