If the density of methanol is `0.793 kg L^(-1)`, what is its volume needed for making 2.5 L of its 0.25 M solution ?

Explanation

Density `= 0.793 Kg//L = 0.793 xx 10^(3) gm//L`
Final volume `= 2.5 L = V_(2)`
final molarity `= 0.25M = M_(2)`
Molecular mass of methanol `(CH_(3)OH)`
`= (1xx12.01) + 4 (1.0079) + 16.00`
`= 32.0416 ~= 32` gm/mol
Molarity `= ("Density")/("Molecular mass") = (0.793xx10^(3) gm//L)/(32 gm//L)`
`=24.781` mol/L
`M_(1)V_(1) = M_(2)V_(2)`
`:.24.781xxV_(1) = 0.25xx2.5`
`:.V_(1)=(0.25xx2.5)/(24.781)=0.02522 L = 25.22` mL