An impure sample of (COOH)2 · 2 H2O that has a mass of 4.3 g was dissolved in water and titrated with standard NaOH solution. The titration required 44.5 mL of 0.11 mo- lar NaOH solution. Calculate the percent (COOH)2 · 2 H2O in the sample.

Question

An impure sample of (COOH)2 · 2 H2O that has a mass of 4.3 g was dissolved in water and titrated with standard NaOH solution. The titration required 44.5 mL of 0.11 mo- lar NaOH solution. Calculate the percent (COOH)2 · 2 H2O in the sample.
Answer in units of %.

DrBob222 · Accepted Answer

H2C2O4.2H2O + 2NaOH ==>Na2C2O4 + 4H2O

mols NaOH = M x L = 0.11 x 0.0445 = ?
mols H2C2O4.2H2O used = 1/ 2 x mols NaOH = ? (note that 2 mols NaOH = 1 mol H2C2O4.2H2O)
grams H2C2O4.2H2O in sample = mols H2C2O4.2H2O x molar mass = ?
% H2C2O4.2H2O = (grams H2C2O4.2H2O/4.3 g)*100 = ?

Post your work if you get stuck.

Big Boy · Answer

Perfect, thank you for your help, DrBob222!