Question

Calculate the amount of heat (in kilojoules) associated with 169 g of mercury cooling from 78.8°C to 12.5°C. The specific heat of mercury is 0.139 J/g·°C. Do not include a sign in your answer.

Answer 1

In kJ the heat released = 1.5574 kJ = 1.56 kJ

Step-by-step explanation:

The specific heat of a substance is the amount of heat change when one gram of a substance undergoes a temperature change on 1 degree celsius.

The formula will be:

`Heat change=specificheatXchangeintemperatureXmass`

mass = 169 g

specific heat = 0.139 J/g·°C

temperature change = [78.8°C]-[ 12.5°C]=66.3 °C

Heat released =
`169X66.3X0.139=1557.4J`

In kJ the heat released = 1.5574 kJ

Answer 2

The amount of heat associated with 169 g of mercury is 1.557 kiloJoules.

Step-by-step explanation:

Mass of mercury = m = 169 g

Change in temperature of the mercury =
`\Delta T=12.5^oC-78.8^oC=-66.3^oC`

The specific heat of mercury = c = 0.139 J/g°C

Heat associated with mercury: Q

`Q=mc\Delta T`

`Q=169 g* 0.139 J/g ^oC* (-66.3^oC)=1,557.45 J=1.557 kJ`

Negative sign indicates that heat was released when mercury is cooled down.

The amount of heat associated with 169 g of mercury is 1.557 kiloJoules.