Problem: A 0.167-g sample of an unknown acid requires 27.8 mL of 0.100 M NaOH to titrate to the equivalence point. Elemental analysis of the acid gives the following percentages by mass: 40.00% C; 6.71% H; 53.29% O.Determine the molar mass of the unknown acid.

FREE Expert Solution

We have to determine the molar mass of the unknown acid using the given data.


When acid and a base react, the number of moles of the acid can be determined by the number of moles of the base using a balanced chemical equation.


We will solve this problem through these steps:

Step 1: Write a balanced equation for the acid-base reaction.

Step 2: Calculate the number of moles of NaOH from its volume and molarity.

Step 3: Calculate the number of moles of unknown acid.

Step 4: Calculate the molar mass of unknown acid.

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Problem Details

A 0.167-g sample of an unknown acid requires 27.8 mL of 0.100 M NaOH to titrate to the equivalence point. Elemental analysis of the acid gives the following percentages by mass: 40.00% C; 6.71% H; 53.29% O.

Determine the molar mass of the unknown acid.

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 Equivalence Point concept. If you need more Equivalence Point practice, you can also practice Equivalence Point practice problems.