Answer:
0.3M
Step-by-step explanation:
Step 1:
Data obtained from the question. This include the followingb:
Volume of acid (Va) = 90mL
Concentration of acid (Ca) = 0.2M
Volume of base (Vb) = 60mL
Concentration of base (Cb) =....?
Step 2:
The balanced equation for the reaction. This is given below:
HBr + NaOH —> NaBr + 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 concentration of the base, NaOH.
The concentration of the base can be obtained as follow:
CaVa /CbVb = nA/nB
0.2 x 90 / Cb x 60 = 1
Cross multiply
Cb x 60 = 0.2 x 90
Divide both side by 60
Cb = 0.2 x 90 /60
Cb = 0.3M
Therefore, the concentration of the base, NaOH is 0.3M