Given:
The initial mass of charcoal=3g
Vol. of acetic acid =50mL Normality=0.06N
Strength of filtrate after reaction=0.042N
We know,
Molarity of acetic acid soln=Wt/MVol of soln
⇒Wt=0.06×60×0.05=0.180g
Also, normality after reaction, 0.042=W60×0.05
W=0.126g
Change in mass=0.180−0.126=0.054g=54mg
Amount of charcoal available=3g
Amount of acetic acid absorbed =54mg3.0g×1.0g=18g
Correct option is A.