Q. 94.3( 36 Votes )

A sample of drinking water was found to be severely contaminated with chloroform (CHCl3) supposed to be a carcinogen. The level of contamination was 15 ppm (by mass):

(i) express this in percent by mass

(ii) determine the molality of chloroform in the water sample.

Answer :

Given:

Level of contamination = 15 ppm [by mass]


To find: Mass Percentage and Molality


Formula:


Molality


Mass Percentage of Solute


Solution:


Calculation of Mass Percentage:


15 ppm means 15 parts of Chloroform in 106 parts of drinking water


Mass Percentage



= 1.5 × 10-3


Calculation of Molality:


Molecular Mass of Chloroform, CHCl3 = [12] + [1] + [35.5 × 3]


= 119.5 g


Number of Moles of Chloroform = [15 / 119.5]


= 0.1255 moles


Molality



= 1.255 × 10-4


Therefore the Mass Percentage is = 1.5 × 10-3 and the Molality of the solution is = 1.255 × 10-4 m.


Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Related Videos
Solutions - 07Solutions - 07Solutions - 0743 mins
Relative Lowering in Vapour pressure and Elevation in Boiling pointRelative Lowering in Vapour pressure and Elevation in Boiling pointRelative Lowering in Vapour pressure and Elevation in Boiling point56 mins
Colligative properties | Mastering important conceptsColligative properties | Mastering important conceptsColligative properties | Mastering important concepts46 mins
Elevation in BP | A Thorough lectureElevation in BP | A Thorough lectureElevation in BP | A Thorough lecture43 mins
Ideal & Non Ideal Solutions {Concept Class}Ideal & Non Ideal Solutions {Concept Class}Ideal & Non Ideal Solutions {Concept Class}39 mins
Quiz | Depression in Freezing Point - 02Quiz | Depression in Freezing Point - 02Quiz | Depression in Freezing Point - 0241 mins
Learn Depression in Freezing Point in an HourLearn Depression in Freezing Point in an HourLearn Depression in Freezing Point in an Hour35 mins
Non Ideal SolutionsNon Ideal SolutionsNon Ideal Solutions52 mins
Rapid Revision | Chapter - SolutionsRapid Revision | Chapter - SolutionsRapid Revision | Chapter - Solutions70 mins
Types of solution on the basis of Raoult's LawTypes of solution on the basis of Raoult's LawTypes of solution on the basis of Raoult's Law44 mins
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
caricature
view all courses