What is the volume occupied by 0.259 mol of helium gas at 1.21 atm and 309 K?

How does a hydroelectric power plant converts energy into energy.

What is the mass of oxygen gas is consumed in a reaction that produces 4.60mol so2

Nitric acid can be formed in two steps from the atmospheric gases nitrogen and oxygen, plus hydrogen prepared by reforming natural gas. in the first step, nitrogen and hydrogen react to form ammonia: (g) (g) (g) in the second step, ammonia and oxygen react to form nitric acid and water: (g) (g) (g) (g) calculate the net change in enthalpy for the formation of one mole of nitric acid from nitrogen, hydrogen and oxygen from these reactions. round your answer to the nearest .