"a sample of helium gas at 27.0 °c and 4.20 atm pressure is cooled in the same container to a temperature of -73.0 °c. what is the new pressure? "

2.80 Atm

Explanation:

Gay-lussac's law

P1÷T1=P2÷T2

T2·P1÷T1

(200)·(4.20)÷300

the reaction mixture contains some ammonia, plus a lot of unreacted nitrogen and hydrogen. the mixture is cooled and compressed, causing the ammonia gas to condense into a liquid. the liquefied ammonia is separated and removed. the unreacted nitrogen and hydrogen are then recycled back into the reactor .

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.