0.079M
Explanation:
Step 1:
Writing a balanced equation for the reaction. This is illustrated below:
H2C3H2O4 + 2NaOH —> C3H2Na2O4 + 2H2O
From the balanced equation above, the following were obtained obtained:
Mole of the acid (nA) = 1
Mole of the base (nB) = 2
Step 2:
Data obtained from the question. This includes:
Molarity of the base (Mb) = 0.1M
Volume of the base (Vb) = 20.76mL
Molarity of the acid (Ma) =?
Volume of the acid (Va) = 13.15mL
Step 3:
Determination of the molarity of the acid.
Applying the equation:
MaVa/MbVb = nA/nB
The molarity of the acid can be obtained as follow:
MaVa/MbVb = nA/nB
Ma x 13.15 / 0.1 x 20.76 = 1/2
Cross multiply to express in linear form
Ma x 13.15 x 2 = 0.1 x 20.76
Divide both side by 13.15 x 2
Ma = (0.1 x 20.76) / 13.15 x 2
Ma = 0.079M
Therefore, the molarity of the acid is 0.079M