Question

please answer the 12th question explaining the whole solution

Answer 1

Molar mass of methanol (CH3OH) = (1 × 12) + (4 × 1) + (1 × 16)= 32 g mol–1= 0.032 kg mol–1 (divide by 1000 to convert in Kg )
Molarity of methanol solution=0.793 Kg L-1/ 0.032 Kg mol -1= 24.78 mol L–1
  
(Since density is mass per unit volume)
Applying,
M1V1 = M2V2
(Given solution) (Solution to be prepared)
(24.78 mol L–1) V1= (2.5 L) (0.25 mol L–1)V1
V1 = 0.0252 L (multiply by 1000 to convert in ml )
= 25.22 ml