we need to use the effusion formula. I have attached a picture of what this formula looks like because it is a bit hard to type.
effusion formula---> Rate 1/ rate 2= √(M2/M1)
as the questions states, hydrogen gas rate is 4 times the rate of the other gas. so, let call gas 1 the unknown and gas 2 the hydrogen
Rate 1= 1
Rate 2= 4
M1=??
M2= 2 grams
now let's plug in the values and solve for the unknown
1/4 = √(2/x)
x= 32 grams
with the choices given, the gases are either O₂, N₂ or O₃.
O₂ is the one whose mass is 32 because oxygen atomic mass in the periodic table is 16 grams. since we have two oxygens, then 16 x 2= 32
the answer is "32 grams and oxygen "