[either_oar]

Ok, so my class did a lab where magnesium reacts with HCl to produce hydrogen gas into a collection tube. here are my results:

Barometric Pressure: 101.6 kPa
Room Temperature: 301K
Mass of Magnesium: 0.03g
Temperature of Water: 293 K
Volume of gas in collection tube: 31 mL

now it asks to calculate the pressure exerted by the dry hydrogen gas... Our teacher mentioned something about water vapour too, and I'm just not sure where to start. This is the basis for all the other questions, so once i get this one, the other should be fine.

thanks in advance, reply if the question is unclear and I'll try to clarify.

[Borek]

You have measured volume occupied by two gases - hydrogen and water. What is the saturated water vapor pressure at 293 K?

[Donaldson Tan]

You use the inverted-jar-in-water technique to collect hydrogen gas.

The hydrogen gas passes through water before it becomes collected inside the inverted jar. The hydrogen gas collected thus must be moist, and its moisture content should be related to the temperature of water.

Based on the mass of magnesium reacted, how manu moles of hydrogen gas should you get? How does the molar quantity relates to the partial pressure of the gas?

[either_oar]

ok so im figuring out the pressure of the H₂ by doing

P_T = P _H2 + P _H2O
      =P _H2 + 2.3 kPa

but now im stuck... is my total pressure the Barometric pressure???

[either_oar]

ok nvm, i've figured out a bit more. just one more question.

Volume of gas at STP?

PV=nRT

or

P₁V₁/T₁= P₂V₂/T₂

[xiankai]

Volume of gas at STP?

22.4 dm³

PV=nRT

or

P₁V₁/T₁= P₂V₂/T₂

same thing, really