Answer:
0.231 M.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
HCl + NaOH —> NaCl + H2O
From the balanced equation above, we obtained the following data:
Mole ratio of the acid, HCl (nA) = 1
Mole ratio of the base, NaOH (nB) = 1
Next, the data obtained from the question:
Volume of base, NaOH (Vb) = 25 mL
Molarity of base, NaOH (Mb) = 0.185 M
Volume of acid, HCl (Va) = 0.0200 L
Molarity of acid, HCl (Ma) =?
Next, we shall convert 0.0200 L to mL
This can be obtained as follow:
1 L = 1000 mL
Therefore,
0.0200 L = 0.0200 L × 1000 mL /1 L
0.0200 L = 20 mL
Thus, 0.0200 L is equivalent to 20 mL.
Finally, we shall determine the molarity of the acid solution as follow:
Mole ratio of the acid, HCl (nA) = 1
Mole ratio of the base, NaOH (nB) = 1
Volume of base, NaOH (Vb) = 25 mL
Molarity of base, NaOH (Mb) = 0.185 M
Volume of acid, HCl (Va) = 20 mL
Molarity of acid, HCl (Ma) =?
MaVa / MbVb = nA/nB
Ma × 20 / 0.185 × 25 = 1
Ma × 20 / 4.625 = 1
Cross multiply
Ma × 20 = 4.625 × 1
Ma × 20 = 4.625
Divide both side by 20
Ma = 4.625 / 20
Ma = 0.231 M
Thus, the molarity of the acid solution is 0.231 M.
