A sample of drinking water severely contaminated with chloroform, CHCl 3, is supposed to be carcinogenic in nature. The level of contamination was 15 ppm (by mass) What is the molality of chloroform in the water sample?

Question

A sample of drinking water severely contaminated with chloroform, CHCl 3, is supposed to be carcinogenic in nature. The level of contamination was 15 ppm (by mass) What is the molality of chloroform in the water sample? (A) 2.25 × 10-5 m (B) 1.25 × 10-4 m (C) 1.85 × 10-6 m (D) 1.72 × 10-5 m

Tardigrade Admin · Accepted Answer

15 ppm means 15 g of CHCl 3 are dissolved in 106 g of solvent. Molality =(wB / mB/ text Mass of solvent ) × 1000 wB=15 g , mB=119.5, MB=106 g Molality =(15 / 119.5/106) × 1000 =1.25 × 10-4 m

Q. A sample of drinking water severely contaminated with chloroform, $C H C l_{3}$ , is supposed to be carcinogenic in nature. The level of contamination was $15 pp m$ (by mass) What is the molality of chloroform in the water sample?

$2.25 \times 1 0^{- 5} m$

$1.25 \times 1 0^{- 4} m$

$1.85 \times 1 0^{- 6} m$

$1.72 \times 1 0^{- 5} m$

$15 pp m$ means $15 g$ of $C H C l_{3}$ are dissolved in $1 0^{6} g$ of solvent. Molality $= \frac{w _{B} / m _{B}}{Mass of solvent} \times 1000$

$w_{B} = 15 g, m_{B} = 119.5, M_{B} = 1 0^{6} g$

Molality $= \frac{15/119.5}{1 0 ^{6}} \times 1000$

$= 1.25 \times 1 0^{- 4} m$

Q. A sample of drinking water severely contaminated with chloroform, CHCl3​, is supposed to be carcinogenic in nature. The level of contamination was 15ppm (by mass) What is the molality of chloroform in the water sample?

2.25×10−5m

1.25×10−4m

1.85×10−6m

1.72×10−5m