The AC unit uses a refrigerant generally a chemical called freon to cool the air in a house. The unit evaporates freon and uses the result of this evaporation cycle to circulate cool air. ... Freon is a gas. The AC unit compresses this cool gas, causing it to become very hot.
Equation a. C3H8(g) + O2(g) → CO2(g) + H2O(g) + 2220 kj
is endothermic. + 2220 kj
Equation b. 2 Na(s) + Cl2(g) → 2 NaCl(s) + 819kJ
is also endothermic since the overall energy change is positive. + 819kJ
The equation c. PCl5(g) + 67kj → PCl3(g) + Cl2(g) is endothermic since it requires anergy to proceed.
<span>sunspots, hope this helps!!!!</span>
As long as the chemical is not used up in the reaction the answer is true