Page 98 - Chemistry - XI
P. 98
Result
The increasing order of acid present in tea samples is __________________.
PROJECT - 6
Introduction
The rate of evaporation depends upon boiling point of a liquid. Boiling point depends upon intermolecular
forces of attraction. The lesser the intermolecular forces of attraction, lower will be the boiling point, more
easily liquid will get vaporised. Highly volatile liquids are stored in airtight containers at low temperature.
Objective
To study the relationship between the rates of evaporation of diff erent liquids and their chemical constitution.
Principle/Theory
The rate of evaporation depends upon nature of liquid, i.e. its boiling point, surface area, wind speed,
and atmospheric pressure. Relate the diff erence in rates of evaporation of liquids with their chemical
constitution.
Materials Required
Five clean weighting tubes or bottles with stopper, 10 mL of ethanol, ether, carbon tetrachloride, acetone,
chloroform, and digital balance
Procedure
1. Take fi ve clean dry weighing bottles and mark them as A, B, C, D, and E.
2. Weigh each weighing tube with its stopper.
3. Pour 10 mL of ethanol in A, ether in B, carbon tetrachloride in C, acetone in D and chloroform in E in
each weighing bottle.
4. Weigh each weighing bottle again and fi nd the mass of liquid taken in a weighing bottle.
5. Remove all the stoppers of the weighing bottles and keep them at room temperature for one hour.
6. After exactly one hour, close the mouth of all the weighing bottles with their stoppers and weigh them
again one by one.
7. Calculate the loss of mass of each liquid and rate of evaporation of each liquid in grams of liquid
evaporated per second.
Observations
Sample Mass of Mass of weighing Mass of Mass of Loss of Rate of
weighing bottle with 10 mL liquid weighing bottle mass of evaporation/
bottle of liquid after 1 hour liquid sec
A
B
C
D D
E E
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