How many Calories are needed to heat up a 2 liter bottle of liquid from 0 degrees to 100 degrees Celsius?

Answer 1

It depends on the liquid contained in the bottle and the material the bottle is constructed from.

The definition of a Calorie is the amount of energy required to raise the temperature of one gram of water by one degree Celsius, therefore to heat 2 litres of water (which weighs 2000g) by 100 degrees C = 200.000 Calories.

N.B. The water will be at 100 C, to convert into steam, the energy required for phase change must be considered.

The effect of the bottle has been ignored in this answer.

To add to the confusion:

This definition is the "real" calorie as defined and used in physics and chemistry etc.

The calorie used in food, exercise etc is really a kilocalory.

It is abbreviated kcal, but is often read as calories, not kilokalories.

If you mix this up, you get the wrong answer that a liter of cola contains approx 430 calories, but to heat it from 7 to 37 degrees celcius takes 30.000 calories.

Answer 2

The amount of calories needed to heat up a substance can be calculated using the specific heat capacity of the substance. For water, the specific heat capacity is 1 calorie/gram°C. A 2-liter bottle of water weighs around 2000 grams. To raise the temperature of 2000 grams of water from 0°C to 100°C, you would need approximately 200,000 calories.