Consider the following table

Substitute Melting point / ºC Boiling  point / ºC
P – 78 -25
Q – 8 40
R  – 6 150
S 44 280

 

A. P
B. Q
C. R
D. S

Correct Answer:

Option B = Q

Explanation

Q has slightly lower boiling point which when expose to air may evaporate rapidly.

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