A 10*mL volume of oxalic acid was titrated with a 34.40*mL volume of NaOH(aq) whose concentration was 0.250*mol*L^-1. What was the mass of oxalic acid present in the initial 10*mL volume?

1 Answer
Jul 31, 2017

[C_2O_4H_2]~=0.5*mol*L^-1.

Explanation:

We need (i) a stoichiometric equation.....

"HO(O=)CC(=O)OH + 2NaOH"rarrC_2O_4^(2-)Na_2^+ + 2H_2O

And (ii) equivalent quantities of sodium hydroxide......

"Moles of NaOH"=34.40*mLxx10^-3*L*mL^-1xx0.250*mol*L^-1=8.60xx10^-3*mol.

And HALF this molar quantity was equivalent to the oxalic acid solution contained in 10.00*mL solution.

"Concentration of oxalic acid"=(1/2xx8.60xx10^-3*mol)/(10.00xx10^-3*L^-1)

=0.430*mol*L^-1

And thus in a 10*mL volume, there were 10xx10^-3*Lxx0.430*mol*L^-1xx90.03*g*mol^-1=

~=0.4*g ""