Answer : The molar heat of solution of KCl is, 17.19 kJ/mol
Explanation :
First we have to calculate the heat of solution.

where,
q = heat produced = ?
c = specific heat capacity of water = 
= change in temperature = 0.360 K
Now put all the given values in the above formula, we get:


Now we have to calculate the molar heat solution of KCl.

where,
= enthalpy change = ?
q = heat released = 460.8 J
m = mass of
= 2.00 g
Molar mass of
= 74.55 g/mol

Now put all the given values in the above formula, we get:


Therefore, the molar heat of solution of KCl is, 17.19 kJ/mol
Answer:
0.8078 Kg
Explanation:
Pressure of water = 0.15 MPa = 1.5 bar
At critical point of water ,temperature = 647 K=374°C
From the ideal gas equation
P×V= m×R×T
Let us assume volume = 1 m^3
1.5 x 105 x 1 = m x 287 x 647
m= 0.8078 kg
the fraction of mass of liquid at 25°C.