# A 25.0 mL sample of sulfuric acid is completely neutralized by 32.8 mL of 0.116 mol/L ammonia solution. Ammonium sulfate is formed What is the concentration of the sulfuric acid?

Dec 19, 2016

Approx. $0.08 \cdot m o l \cdot {L}^{-} 1$ with respect to sulfuric acid.

#### Explanation:

We need (i) a stroichiometric equation:

${H}_{2} S {O}_{4} \left(a q\right) + 2 N {H}_{3} \left(a q\right) \rightarrow 2 N {H}_{4}^{+} + S {O}_{4}^{2 -}$

At the 2nd equivalence point, the solution will stoichiometric in $\text{ammonium sulfate}$. An appropriate indicator must be used.

And (ii) a calculation,

$\left[{H}_{2} S {O}_{4}\right] = \frac{1}{2} \times \frac{32.8 \times {10}^{-} 3 \cdot L \times 0.116 \cdot m o l \cdot {L}^{-} 1}{25.0 \times {10}^{-} 3 \cdot L}$

=??*mol*L^-1

Why did we use a $\frac{1}{2}$ factor in the calculation?