How many kilocalories are required to increase the temperature of 15.6 g of iron from 122 °c to 355 °c. the specific heat of iron is 0.450 j/g °c?

Heat require to boil 15.6 g iron from 122 C0to 355 C0 whereas,

Where, m is mass of iron

s is specific heat of iron

d T is change in temperature in celcius

If  

1 cal = 4.2 J

Then,  

Thus 0.389 k cal of enrgy  is required by a 15.6 g Fe to reach to 355 C^0

b.

the accuracy of the data.

"record the time to complete a chemical reaction" would most likely be part of a lab procedure.