Question

How much energy must be added to a bowl of 125popcorn kernels in order for them to reach a popping temperature of 175°C? Assume that their initial temperature is 21°C, that the specific heat capacity of popcorn is 1650 J/kg•°C, and that each kernel has a mass of 0.105 g.

Answer 1

Answer:

3,335.06 Joules of an energy must be added to a bowl of 125 popcorn kernels in order for them to reach a popping temperature of 175°C.

Explanation:

Number of popcorn kernels = 125

Mass of single popcorn kernel = 0.105 g

Mass of 125 popcorn kernel = m = 125 × 0.105 g  = 13.125 g = 13.125 × 0.001 kg

1 g = 0.001 kg

Specific heat of popcorn = c = 1650 J/kg°C

Initial temperature of the popcorn kernels = $T_1=21^oC$

Final temperature of the popcorn kernels = $T_2=175^oC$

Heat added to popcorn kernel to rise their temperature to popping temperature be Q.

$Q=m\times c\times (T_2-T_1)$

$Q=13.125\times 0.001 kg\times 1650 J/kg^oC(175^oC-21^oC)$

Q = 3,335.06 J

3,335.06 Joules of an energy must be added to a bowl of 125 popcorn kernels in order for them to reach a popping temperature of 175°C.