Compound A is added into a calorimeter that contains 0.750 litres of water. If the dissolution of 5.0 g of this compound causes the temperature of the water to rise to 45.0 °C, what is the enthalpy of solution of compound A?
To calculate the enthalpy of solution of compound A, we need to use the equation:
q = m * c * ΔT
Where:
- q is the heat absorbed or released by the water (calorimeter)
- m is the mass of water
- c is the specific heat capacity of water
- ΔT is the change in temperature of the water
First, let's find the values required to substitute into the equation:
m = 0.750 L * 1000 g/L = 750 g (since 1 L of water has a mass of 1000 g)
c = 4.18 J/g·°C (specific heat capacity of water)
ΔT = (final temperature) - (initial temperature) = 45.0 °C - (initial temperature)
Now, let's calculate the value of ΔT. Since the initial temperature of the water is not provided in the question, we can assume it to be 25.0 °C (room temperature). Therefore:
ΔT = 45.0°C - 25.0°C = 20.0°C
Now, we can substitute the values into the equation and solve for q:
q = 750 g * 4.18 J/g·°C * 20.0°C
q = 62700 J
Since the dissolution of 5.0 g of compound A caused the water to absorb 62700 J of heat, the enthalpy of solution of compound A can be calculated as follows:
Enthalpy of solution = q / amount of compound A
Enthalpy of solution = 62700 J / 5.0 g
Enthalpy of solution = 12540 J/g
Therefore, the enthalpy of solution of compound A is 12540 J/g.