Question

Ethylene glycol, used as a coolant in automotive engines, has a specific heat capacity of 2.42 j/(g·°c). calculate q when 3.65 kg of ethylene glycol is cooled from 132 °c to 85 °c.

Answer 1

Answer:

-415 J

Explanation:

The amount of heat released when the ethylene glycol is cooled is given by:

$Q=mC_S \Delta T$

where:

m = 3.65 kg = 3650 g is the mass of the ethylene glycol

Cs = 2.42 j/(g·°c) is the specific heat capacity of the substance

$\Delta T = T_f -T_i = 85^{\circ}C-132^{\circ}C=-47^{\circ}C$ is the change in temperature of the coolant

By substituting the numbers into the equation, we find

$Q=(3650 g)(2.42 J/(g^{\circ}C))(-47^{\circ}C)=-4.15\cdot 10^5 J = -415 kJ$

And the sign is negative because the heat is released by the system.