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 ?

If the density of methanol is 0.793 kg L^(-1), what is its volume need

1.	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 ?
Answer» Solution :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