Use Henry's law to determine the molar solubility of helium at a pressure of 1.5 atm and 25 ∘C. Henry’s law constant for helium gas in water at 25 ∘C is 3.70⋅10−4M/atm.?

The solubility of helium is ##5.6 × 10^(-4) "mol·L"^(-1)##.

Henry's Law is often written as

##C = kP##,

where ##C## is the concentration of the gas in the solution, ##P## is the of the gas, and ##k## is a proportionality constant.

For your problem,

##C = kP = 3.70 × 10^(-4) "mol·L"^(-1)color(red)(cancel(color(black)("atm"^(-1)))) × 1.5 color(red)(cancel(color(black)("atm"))) = 5.6 × 10^(-4) "mol·L"^(-1)##.