Answer:
198.8mL
Explanation:
Step 1:
Data obtained from the question:
Molarity of base (Mb) = 3.5M
Volume of base (Vb) =..?
Molarity of acid (Va) = 2.75M
Volume of acid (Va) = 253mL
Step 2:
The balanced equation for the reaction.
HF + LiOH —> LiF + H2O
From the balanced equation above,
The mole ratio of the acid (nA) = 1
The mole ratio of the base (nB) = 1
Step 3:
Determination of the volume of the base, LiOH needed for the reaction.
The volume of the base needed for the reaction can be obtained as follow:
MaVa /MbVb = nA/nB
2.75 x 253 / 3.5 x Vb = 1
Cross multiply
3.5 x Vb = 2.75 x 253
Divide both side by 3.5
Vb = 2.75 x 253 / 3.5
Vb = 198.8mL
Therefore, the volume of the base needed for the reaction is 198.8mL
