57. Molality of 2,5 g of ethanoic acid (CH,COOH) in 75 g benzene isA A

1.	57. Molality of 2,5 g of ethanoic acid (CH,COOH) in 75 g benzene isA A) 0.565 mol kg-1B) 0.656 mol kg1556 mol kgD) 0.665 mol kg1
Answer» Molecular Mass of CH3COOH - 60 gm Given mass of CH3COOH - 2.5 gms = Moles of CH3COOH = 2.5/60 = 0.0416666..... = 0.0417 approx. Given mass of solvent (benzene in this case) = 75g Molality (m) = (moles of solute/(gms of solvent/1000)) = 0.0417/(75/1000) = 0.0417*1000/75 = 41.7/75 = 0.556 molal

57. Molality of 2,5 g of ethanoic acid (CH,COOH) in 75 g benzene isA A) 0.565 mol kg-1B) 0.656 mol kg1556 mol kgD) 0.665 mol kg1

Answer»

Molecular Mass of CH3COOH - 60 gm

Given mass of CH3COOH - 2.5 gms

= Moles of CH3COOH = 2.5/60 = 0.0416666..... = 0.0417 approx.

Given mass of solvent (benzene in this case) = 75g

Molality (m) = (moles of solute/(gms of solvent/1000))

= 0.0417/(75/1000)

= 0.0417*1000/75

= 41.7/75 = 0.556 molal