Concept explainers
Trichloroethane, C2H3Cl3, is the active ingredient in aerosols that claim to stain-proof men's ties. Trichloroethane has a vapor pressure of 100.0 mm Hg at 20.0°C and boils at 74.1°C. An uncovered cup
Interpretation:
The percentage (by mass) of the trichloroethane that remains as a liquid when equilibrium is established should be calculated.
Concept introduction:
The relation between vapor pressure ( P), temperature ( T) and molar heat of vaporization
Here, A is the y-intercept, which is a constant for any given line.
R is the gas constant.
Answer to Problem 78QAP
The amount of trichloroethane is left as a liquid is
Explanation of Solution
Given:
Vapor pressure of trichloroethane = 100.0 mm Hg at 20 °C
Boiling point = 74.1 °C
Volume of cup = ½ pint
Density = 1.325 g/mL
18 ft3 refrigerator at 39 °F
The relation between vapor pressure ( P), temperature ( T) and molar heat of vaporization
Here, A is the y-intercept, which is a constant for any given line.
R is the gas constant.
For vapor pressure
At
The vapor pressure of
Substitute the values in equation (1) and calculate
Molar heat of vaporization of liquid
Convert the temperature of refrigerator
With the values of
Therefore, vapor pressure of
Ideal gas law is:
Here, P represent pressure, V represents volume, n represents number of moles, R represents gas constant and T represents temperature.
Given, volume of
Calculate the number of moles and the mass of vapor formed in the refrigerator as follows:
Calculate the mass of liquid
313.5 g of the liquid, 174.75 is vaporized. Thus, the mass of liquid at left is
Calculate the mass percentage of liquid left at equilibrium to take the ratio of liquid mass left to the initial liquid mass and then multiply by
Thus, the amount of trichloroethane is left as a liquid is
The amount of trichloroethane is left as a liquid is
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Chapter 9 Solutions
EBK CHEMISTRY: PRINCIPLES AND REACTIONS
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