The Science of Calorimetry: Calculating Heat Energy

How do we calculate the number of calories required to raise the temperature of water?

The number of calories required to raise the temperature of 55.0 g of water (c = 1.00 cal/g°C) from 25°C to 45°C is ________.

1) 1.10 x 10³ cal

2) 1380 cal

3) 2480 cal

4) 55.0 cal

Answer:

The number of calories required to raise the temperature of 55.0 g of water from 25°C to 45°C is 1,100 calories.

Calorimetry is the science of measuring the heat of chemical reactions or physical changes. One common application of calorimetry is calculating the amount of heat energy required to raise the temperature of a substance, such as water.

In the given scenario, we are asked to calculate the number of calories needed to raise the temperature of 55.0 g of water from 25°C to 45°C. To do this, we can use the formula:

q = mcΔT

Where:

q = heat energy

m = mass of the water (55.0 g)

c = specific heat of water (1.00 cal/g°C)

ΔT = temperature change (45°C - 25°C = 20°C)

Plugging in the values, we get:

q = (55.0 g)(1.00 cal/g°C)(20°C)

q = 1,100 cal

Therefore, the number of calories required to raise the temperature of 55.0 g of water from 25°C to 45°C is 1,100 calories. Option 1) 1.10 x 10³ cal is the correct answer.