Answer:
The answer is 4.
Explanation:
Take trail mix as a mixture. It can easily be separated by hand. Take sugar in hot coca as a solution. You cannot separate sugar from the hot coca with your hands.
The relationship between pressure and solubility of the gas is given by Henry's law as:

where,
is the solubility of the gas.
is proportionality constant i.e. Henry's constant.
is pressure of the gas.
(given)
(given)
Substituting the values,

To convert
to
:
Molar mass of benzene,
= 

Now for converting into
:
Since, 
So,
.
Hence, the solubility of benzene in water at
in
is
.
Answer:
C
Explanation:
Br + Br-> Br2 (covalent bond)
bond formation releases energy, as the Br's are in a lower energy state like Br2