Assignment:
Q1. a. You are presented with three identical metal containers of about 5 litres capacity, each about half full of fuel. The containers have a short neck and are normally closed by a screw cap of about 30mm diameter. The cans contain:
(i) petrol (gasoline, flashpoint -43oC),
(ii) methyl alcohol (methanol, flashpoint 11oC), and
(iii) paraffin (kerosine, flashpoint 50oC).
Explain concisely what would happen if the top was taken off and a lit match was immediately dropped into the headspace of each of the cans. Assume that the ambient temperature, and thus that of the liquids, is 15oC.
b. State briefly the relationship between the flash point and auto-ignition temperature of a series of related chemicals, for example methane, propane, butane and pentane. Complete the following table:
|
NAME
|
CHEMICAL FORMULA
|
MOLECULAR WEIGHT
|
FLASH POINT
oC
|
AUTO IGNITION TEMPERATURE oC
|
|
Methane
|
CH4
|
|
|
|
|
Ethane
|
C2H6
|
|
|
|
|
Propane
|
C3H8
|
|
|
|
|
Butane
|
C4H10
|
|
|
|
|
(n)Pentane
|
C5H12
|
|
|
|
Provide complete and step by step solution for the question and show calculations and use formulas.