A 28.5 g piece of gold is heated and then allowed to cool. What is the change in temperature (°C) if the gold releases 0.106 kJ

Question

nikitadnepr [17]

2 years ago

12

A 28.5 g piece of gold is heated and then allowed to cool. What is the change in temperature (°C) if the gold releases 0.106 kJ

of heat as it cools? The molar heat capacity of gold is 25.4 J/mol･°C.

Chemistry

1 answer:

Shkiper50 [21] · Answer 1 · 2023-02-17T03:05:08+03:00

Considering the definition of calorimetry and sensible heat, the change in temperature if the gold releases 0.106 kJ of heat as it cools is 28.78°C.

Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.

Sensible heat is the amount of heat that a body absorbs or releases without any changes in its physical state (phase change). It is calculated by the expression:

Q = c× m× ΔT

where Q is the heat exchanged by a body of mass m, made up of a specific heat substance c and where ΔT is the temperature variation.

In this case, you know:

Q= 0.106 kJ= 106 J (being 1 kJ=1000 J)
c= 25.4 $\frac{J}{molC}$
m= 28.5 g× $\frac{1 mole}{196.967 g}$ = 0.145 moles (being 196.967 g/mole the molar mass of gold)
ΔT= ?