Question

How much heat, in calories, is given off when 1.25 grams of silver is cooled from 100.0°C to 80.0°C? (The specific heat of silver is 0.057 cal/g°C)
1.43 cal

0.0713 cal

5.70 cal

7.13 cal

Answer 1

Answer: The correct answer is 1.43 cal.

Explanation:

The expression of heat in terms of mass and temperature is as follows;

$Q= mc\Delta T$

Here, Q is the heat, m is the mass of the object and $\Delta T$ is the change in temperature.

It is given in the problem that 1.25 grams of silver is cooled from 100.0°C to 80.0°C.

Calculate the change in temperature.

$\Delta T=100.0\°C- 80.0\°C$

$\Delta T= 20\°C$

Calculate the heat in calories.

$Q= mc\Delta T$

Put m= 1.25 grams, $\Delta T= 20\°C$  and c=0.057 cal/g°C.

$Q= (1.25)(0.057)(20)$

Q= 1.43 cal

Therefore, the amount of heat is  1.43 cal.

Answer 2

1.43cal is the answer