Explanation:
It is known that 1 SCF produces approximately 1000 Btu of thermal energy.
As it is not mentioned for how many hours the gas is used in this process. Therefore, we assume that the total number of hours natural gas used in this process are as follows.
= 8760 hours
Now, we will calculate the annual cost of natural gas used in the process as follows.
= 555384000 SCF
Hence, annual cost of natural gas used in this process = loss of thermal energy
This will be equal to, 
= 555,384,000,000 BTU
Thus, we can conclude that the annual cost of natural gas used in the process is 555,384,000,000 BTU.
Because the sulfur ion has a negative two charge, the formula would be Fe2S3
An atom that has fewer neurons than protons and more electrons than protons is an ANION
Explanation :
In thermodynamics, a system is region or part of space which is being studied and observed while the surrounding is the region or space around the system which interacts with the system.
Here in the experiment ,system which is observed is reaction or changes when citric acid and sodium bicarbonate are mixed together. And the mixing is carried out in the calorimeter which serves as a surrounding around the system.
The reason behind the using the calorimeter is measure the energy change occurring during the reaction.
