Helppp please : A system releases 4.5 kJ of heat while 4.9 kJ of work is done on it. Calculate AE.

Air can be considered a mixture. which statement does not explain why?

How many moles of water are created if 3 moles of hydrogen react completely with excess oxygen?

0.88 moles of n2o5 (g) was placed in a sealed 1.00 l vessel. calculate the equilibrium concentration of n2o5. no2, and o2 and the equilibrium constant after equilibrium has been reached by 65.0% of the n2o5 decomposing.