Answer:
To determine the amount of heat energy released from the food, we need to use the equation:
q = m * c * ΔT
where:
q is the heat energy in calories,
m is the mass of the food in grams,
c is the specific heat capacity of water (which is approximately 1 calorie per gram per degree Celsius),
ΔT is the change in temperature in degrees Celsius.
In this case, we burned 2.5g of food and used the heat released to heat up the water. The change in temperature is from 25°C to -50°C, which means ΔT = -50°C - 25°C = -75°C.
Using the equation, we have:
q = 2.5g * 1 calorie/g°C * -75°C
Simplifying the calculation, we get:
q = -187.5 calories
Therefore, approximately -187.5 calories of heat energy were released from the food.
Please note that negative values for heat energy indicate heat loss rather than heat gain.