How many n2o4 molecules are contained in 76.3 g n2o4? the molar mass of n2o4 is 92.02 g/mol?

Agas mixture with a total pressure of 745 mmhg contains each of the following gases at the indicated partial pressures: co2, 245 mmhg ; ar, 119 mmhg ; and o2, 163 mmhg . the mixture also contains helium gas. part a what is the partial pressure of the helium gas? phe p h e = nothing mmhg request answer part b what mass of helium gas is present in a 10.2-l sample of this mixture at 283 k ? m m = nothing g request answer

6. what does the symbol ah stand for? o one calorie given off by a reaction the specific heat of a substance the heat capacity of a substance the heat of reaction for a chemical reaction

If a polyatomic ionic compound has gained two hydrogen ions, then how does its name begin?