Problem: A 25.00-mL sample of H2SO4(aq) requires 22.65 mL of the 0.5510 M NaOH for its titration. Assuming that sulfuric acid behaves as a strong acid with respect to both ionizable hydrogen atoms, what was the concentration of the sulfuric acid (H2SO4)?The Kjeldahl analysis is used to determine the protein content of foods. The food analyzed is heated with sulfuric acid in the presence of a catalyst. The carbon in the protein is converted to CO2(g), the hydrogen to water, and the nitrogen to (NH4)2SO4. The mixture is then treated with concentrated NaOH(aq) and heated to drive off NH3(g). The NH3(g) is neutralized by an excess standard acid, and the acid present after the neutralization is titrated with a standard base. From the titration data and the known mass of the sample, the percentage of N can be calculated.Based on the fact that the average percentage of nitrogen in most plant and animal protein is 16.0%, the percentage of protein is obtained by multiplying the percentage of N by the factor (100/16) = 6.25.

FREE Expert Solution
81% (210 ratings)
Problem Details

A 25.00-mL sample of H2SO4(aq) requires 22.65 mL of the 0.5510 M NaOH for its titration. Assuming that sulfuric acid behaves as a strong acid with respect to both ionizable hydrogen atoms, what was the concentration of the sulfuric acid (H2SO4)?


The Kjeldahl analysis is used to determine the protein content of foods. The food analyzed is heated with sulfuric acid in the presence of a catalyst. The carbon in the protein is converted to CO2(g), the hydrogen to water, and the nitrogen to (NH4)2SO4. The mixture is then treated with concentrated NaOH(aq) and heated to drive off NH3(g). The NH3(g) is neutralized by an excess standard acid, and the acid present after the neutralization is titrated with a standard base. From the titration data and the known mass of the sample, the percentage of N can be calculated.

Based on the fact that the average percentage of nitrogen in most plant and animal protein is 16.0%, the percentage of protein is obtained by multiplying the percentage of N by the factor (100/16) = 6.25.

Frequently Asked Questions

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Solution Stoichiometry concept. You can view video lessons to learn Solution Stoichiometry. Or if you need more Solution Stoichiometry practice, you can also practice Solution Stoichiometry practice problems.

What professor is this problem relevant for?

Based on our data, we think this problem is relevant for Professor Stephenson's class at CSULA.