Help I need help with this!!What is percent yield? Explain what it is and how it is calculated.

What would most likely be the transmittance of a 0.70 m solution of solute a?

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

If 1.63 times 10 negative 4 of helium dissolves in 100.0g of water, what is the concentration in parts per million