Answer:
for the process is -375 kJ
Explanation:
- Given reaction is a combination of the two given elementary steps.
- Summation of change in standard enthalpy (
)of the two elementary reactions give
of the reaction
.
......
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= 
Using natural gas is cheaper from other fossil fuels when used for personal needs. It also doesn't pollute the ground or the underground water.
I would say that descriptive investigations aren't repeatable because it means that you are only describing something - you ask certain question about something, but do not form a hypothesis at that point yet. So it would be a waste of time to simply ask the same questions over and over again with no hypothesis to prove, which is why these types of investigations cannot be repeated.
the ion version of potassium is k+