Liquid sodium is being considered as an engine coolant. How many grams of liquid sodium (minimum) are needed to absorb 9.50 MJ of energy (in the form of heat) if the temperature of the sodium is not to increase by more than 10.0 °C? Use CP= 30.8 J/(K·mol)

1 Answer

709,415.58 g

Explanation:

Energy to be absorbed by Na = 9.50 MJ

#Q = m.c_p.dT#

#m= Q/(c_p.dT)#

#m= (9.5*10^6 J) /(30.8 J/(K.mol )*10 K#

#m = 30844.16 mol#

#m = 30844.16 (mol).23 g/(mol)# = 709,415.58 g (or 709.58 kg)

Note: temperature change in Celsius scale is same as change in Kelvin scale.