Question

A solar heating specialist is considering paraffin (Cp = 2.90 J/g O C) as a storage material for heat. How many kg of paraffin would be needed to collect the amount of energy as 4.73 x 10 3 kg of water?

Answer 1

Answer:

Mass of paraffin that would be needed to collect the amount of energy as 4.73 x 10³ kg of water is 6.85 * 10³ kg

Explanation:

Specific heat capacity of paraffin, Cp = 2.90 J/g.°C = 2900 J/kg.°C

Specific heat capacity of water = 4.20 J/g.°C = 4200 J/kg.°C

Amount of heat energy that can be stored by 4.73 * 10³ kg of water heated through a degree rise in temperature can be calculated as below:

Using  H = mCpθ where m is mass of substance, Cp is specific heat capacity and θ is temperature change

H = 4.73 * 10³ kg * 4200 J/kg.°C * 1°C

H = 19866000 J

Mass of paraffin that would be needed to collect the amount of energy as 4.73 x 10 3 kg of water for a degree rise in temperature is calculated as follows:

H = mCpθ

19866000J = m * 2900 J/kg.°C * 1°C

m = 19866000J / 2900 J/kg

m = 6850.34 kg = 6.85 * 10³ kg

Therefore, mass of paraffin that would be needed to collect the amount of energy as 4.73 x 10³ kg of water is 6.85 * 10³ kg