A slice of pizza has 500 kcal. If we could burn the pizza and use all the heat to warm a 50-L container of cold water, what would be the approximate increase in the temperature of the water? (Note: A liter of cold water weighs about 1 kg.)

Question

Quizplus · Accepted Answer

To solve this problem, we need to use the formula Q = mcΔT, where Q is the amount of heat transferred, m is the mass of the water, c is the specific heat capacity of water, and ΔT is the change in temperature.

Since we have 50 L of water, the mass is approximately 50 kg. The specific heat capacity of water is 1 calorie/gram·°C, or 4.184 joule/gram·°C. Thus, the total heat required to increase the temperature of the water by 1°C is:

Q = (50 kg) x (4.184 J/g·°C) x (1°C) = 2092 J

Since 1 calorie is approximately equal to 4.184 joules, this is equivalent to:

Q = (50 kg) x (1 kcal/kg·°C) x (1°C) = 50 kcal

Therefore, burning a slice of pizza with 500 kcal would provide enough heat to increase the temperature of the water by:

ΔT = (500 kcal) / (50 kg x 1 kcal/kg·°C) = 10°C

So the approximate increase in temperature of the water would be 10°C. Therefore, the best answer choice is E.

A Slice of Pizza Has 500 Kcal