Answer:
Explanation:
I'll assume 1.49 is liters.
All gases occupy 22.4 L for each mole of gas at STP. This makles a very useful, and important, conversion factor:
(22.4L/mole gas) for all gases at STP.
Therefore 1.49L of H2 would be:
(1.49L H2)/(22.4L/mole gas) = 0.0665 moles
The molar mass of H2 is 2, so:
(0.0665 moles)*(2g/mole) = 0.133 grams to 3 sig figs
