Answer:
0.7242 M
Explanation:
Step 1:
Data obtained from the question. This include the following:
Molarity of base, KOH (Mb) = 0.850 M
Volume of base, KOH (Vb) = 38.34 mL
Volume of acid, H3A (Va) = 15.00 mL
Molarity of acid, H3A (Ma) =...?
Step 2:
The balanced equation for the reaction. This is given below:
H3A + 3KOH —> K3A + 3H2O
From the balanced equation above,
The mole ratio of the acid, H3A (nA) = 1
The mole ratio of the base, KOH (nB) = 3
Step 3:
Determination of the concentration of the acid, H3A.
The concentration of the acid, H3A can be obtained as follow:
MaVa / MbVb = nA/nB
Ma x 15 / 0.850 x 38.34 = 1/3
Cross multiply
Ma x 15 x 3 = 0.850 x 38.34
Divide both side by 15 x 3
Ma = (0.850 x 38.34) / (15 x 3)
Ma = 0.7242 M
Therefore, the concentration of acid, H3A is 0.7242 M
