A calorimetry experiment is done in the following manner.
200 g of lead (c=128 j/kg*K) at 100 degree (=100 C) are placed in a container filled with 200g of water (c=4190 j/kg*K) at 20 degree (= 20 C).
The water + lead system comes to a final temperature of 21 degree ( = 21 C).
How much Heat is exchanged with the environment?