Question

Air is a mixture of 21% oxygen, 78% nitrogen, and approximately 1% other trace gases, primarily argon(0.93%). Being cheap and
simple to use, it is the most common diving gas. As its nitrogen component causes nitrogen narcosis, it is considered to have a safe
depth limit of about 40 metres (130 feet) for most divers. Liquid air is an extremely cold liquid in which all the constituent gases are in a
liquid state. Liquid air is obtained by repeated compression, cooling, and expansion of air. We can separate different components of
liquid air by fractional distillation. The increasing order of boiling points of argon, oxygen and nitrogen is Nitrogen<Argon<Oxygen.
A. Name the gas that boils off first during fractional distillation of air.
B. Name the gas that boils off at the last during the fractional distillation of air.
C. What should be the difference in boiling points of two components of a liquid-
liquid mixture to choose fractional distillation as a separation technique?
Select one:
O a. A- Nitrogen B- Oxygen C- more than 25K
O b. A- Nitrogen B- Oxygen C- Less than 25K
O c. A- Oxygen B-Nitrogen C- more than 25K
O d. A- Oxygen
B-Nitrogen C- less than 25K​

Answer 1

Answer:

options (b) is the correct answer

nitrogen, oxygen, less than 25 k