Question

A 100. g iron rod is heated to an unknown initial temperature. While cooling down to a temperature of 25.0 degree C, the rod releases 600.2 J of energy. What was its initial temperature? (The specific heat of iron is 0.452 J/g degree C)

a) 38.3 J
b) 11.7 J
c) 27.7 J
d) 22.3 J

Answer 1

Answer: a)
`38.3^0C`

Step-by-step explanation:

As we know that,

`q=m* c* \Delta T=m* c* (T_(final)-T_(initial))`

where,

q = heat released = -600.2 J

`m` = mass of iron rod =100 g

`T_(final)` = final temperature =
`25.^0C`

`T_(initial)` = initial temperature = ?

`c` = specific heat of iron =
`0.452J/g^0C`

Now put all the given values in equation, we get

`-600.2J=100* 0.452J/g^0C* (25.0-T_(initial))^0C]`

`T_(initial)=38.3^0C`

Therefore, the initial temperature of iron rod was
`38.3^0C`