Answer:
2090 joules are released.
Step-by-step explanation:
Calorimetry is applied to this problem:
Q = m . C . (Final T° - Initial T°)
C is the Specific Heat, a constant for each substance, that determines the heat per unit mass, which is required to raise one degree Celsius.
C for water is 4.18 kJ /kg.°C
We convert the mass of water to kg
50 g . 1kg / 1000 g = 0.05 kg
Let's replace data in the formula:
Q = 0.05 kg . 4.18 kJ /kg.°C (60°C - 70°c)
Q = -2.09 kJ
As we have a negative value, heat is released. We need the |Q| for the value
2.09 kJ . 1000 J /kJ = 2090 joules