Astudent is given 2.19 g of an unknown acid, which can be either oxalic acid, h2c2o4, or citric acid, h3c6h5o7. to determine which acid she has, she titrates the unknown acid with 0.560 m naoh. the equivalence point is reached when 61.0 ml are added. answer the following questions to determine the identity of the unknown acid. how many moles of naoh are consumed

The unknown acid is citric acid.

There is 0.0342 moles of NaOH consumed.

Explanation:

Step 1: Data given

Mass of the unknown acid = 2.19 gram

Titrating with 0.560 M of NaOH

The equivalence point is reached when 61.0 mL are added

Molar mass of oxalic acid = 90.03 g/mol

Molar mass of citric acid = 192.12 g/mol

Step 2: The balanced equations for both acids

The reaction between oxalic acid and NaOH is:

H2C2O4 + 2NaOH → Na2C2O4 + 2H2O

The reaction between citric acid and NaOH is:

H3C6H5O7 +3NaOH → Na3C6H5O7 + 3 H2O

Step 3: Calculate the number of moles of the acid

Moles = mass / Molar mass

In case of oxalic acid: 2.19 grams / 90.03 g/mol = 0.0243 moles

In case of citric acid: 2.19 grams /192.12 g/mol = 0.0114 moles

Step 4: Calculate number of moles of NaOH

The mole of NaOH required for titration;

number of moles  = Molar mass * volume = (0.560 M * 0.061 L) = 0.03416 mol

Step 5: Calculate which acid

For each mole of oxalic 2 moles of NaOH is required, for 0.0243 mol citric acid 0.0243 *2= 0.0486 mol NaOH is required. This is more than the number of moles consumed.

For each mole of citric acid 3 moles of NaOH is required, for 0.0114 mol citric acid 0.0114 * 3= 0.0342 mol NaOH is required. This is the number of moles NaOH used for the titration.

The unknown acid is citric acid. There is 0.0342 moles of NaOH consumed.