5.0 g of NaNO3 is dissolved in 50.0 g of water. The initial temperature of the water was 21 degrees Celsius and the final temperature of the water is 15.7 degrees Celsius.

1)Calculate the heat of solution, DeltaHsolution.
2) calculate the heat of solution, DeltaHsolution, per mole of NaNO3.

To calculate the heat of solution, we need to use the equation:

Q = m × C × ΔT

where:
Q = heat absorbed or released (in Joules)
m = mass of the water (in grams)
C = specific heat capacity of water (4.18 J/g°C)
ΔT = change in temperature (final temperature - initial temperature)

Let's start with the first question and calculate the heat of solution, DeltaHsolution.

1) Calculate the heat of solution, DeltaHsolution:
First, we need to find the heat absorbed or released by the water using the equation mentioned above.

Q = m × C × ΔT
= (50.0 g) × (4.18 J/g°C) × (15.7°C - 21.0°C)

Calculating the above expression:
Q = (50.0 g) × (4.18 J/g°C) × (-5.3°C)
= -1108.3 J

Since the temperature decreased, the water released energy (exothermic process), so the heat is negative.

Therefore, the heat of solution, DeltaHsolution, is -1108.3 Joules.

Now let's move to the second question and calculate the heat of solution, DeltaHsolution, per mole of NaNO3.

2) Calculate the heat of solution, DeltaHsolution, per mole of NaNO3:
To calculate the heat of solution per mole, we will need to know the molar mass of NaNO3. Sodium nitrate (NaNO3) has a molar mass of approximately 85.0 g/mol.

The moles of NaNO3 can be calculated using the given mass:

moles = mass / molar mass
= 5.0 g / 85.0 g/mol

Calculating the above expression:
moles ≈ 0.0588 mol

Now, to calculate the heat of solution per mole, we divide the heat of solution obtained in question 1 by the number of moles:

DeltaHsolution per mole = DeltaHsolution / moles
= -1108.3 J / 0.0588 mol

Calculating the above expression:
DeltaHsolution per mole ≈ -18843 J/mol

Therefore, the heat of solution, DeltaHsolution, per mole of NaNO3 is approximately -18843 Joules/mol.