4 Gas Laws and Stoichiometry Questions

Question

1.) A bacterial culture isolated from sewage produced 34.5 mL of methane, CH4, at 30.0 degrees C and

749 mm Hg. What is the volume of methane at STP (0 degrees C, 760 mm Hg)?

My work: (P1V1)/(T1) = (P2V2)/(T1) --> (749 × 34.5) / (303 K) = (760 × V₂) / (273 K) = V₂ = 30.6 mL

2.) A gas has a volume of 450 mL at 35 degrees C. If the volume changes to 400 mL, what is the new

temperature (give your answer in degrees Celsius).

My answer: = 0.77777 --> 1 degree Celsius (rounded to sig figs)

3.) What volume of Hydrogen gas at STP may be prepared by the reaction of 7.62 g gallium

(Ga) with an excess of hydrochloric acid (HCl)? Use the following balanced reaction to find

your answer:

2Ga _(s) + 6HCl _(aq) → 2GaCl_{3 (aq)} + 3H₂

My answer = 3.67 L of H₂

4.) A volume of nitrogen, N₂, required for 68.3 seconds to effuse from a hole in a chamber.

Under the same conditions, another gas required 51.6 seconds for the same volume to

effuse. What is the molar weight of this gas?

My answer = 16.0 g/mol

Answer 1

I agree with all of your answers.