The mass of water in a single popcorn kernel was found to be 0.905 grams after it popped at a temperature of 175 °C. Using the information given in the Introduction, calculate the amount of heat in kilojoules required to pop this single kernel if the room temperature was recorded to be 21.0 °C.

0.583 kilojoules

Explanation:

The amount of heat required to pop a single kernel can be calculated using the formula as follows:

Q = m × c × ∆T

Where;

Q = amount of heat (J)

m = mass of water (g)

c = specific heat capacity of water (4.184 J/g°C)

∆T = change in temperature

From the given information, m = 0.905 g, initial temperature (room temperature) = 21°C , final temperature = 175°C, Q = ?

Q = m × c × ∆T

Q = 0.905 × 4.184 × (175°C - 21°C)

Q = 3.786 × 154

Q = 583.044 Joules

In kilojoules i.e. we divide by 1000, the amount of heat is:

= 583.04/1000

= 0.583 kilojoules