Will mark you brainliest and give you 15

what is the mass of 22.4 l of o2 at stp?

a. 31.99 grams.
b. 22.4 grams.
c. 15.99 grams.
11.2 grams.

The answer to your question is a

1 mole of a gas at STP occupies volume = 22.4 L

And

1 mole of of an element has a mass = Gram molecular mass (if it is molecule and O2 at STP is a molecule O2) = 2 x (atomic mass) =2 x 16 = 32 g

Since 22.4 L at STP = 1 mole =32 g of O2.

Note:

Some gases are monoatomic (like He,Ar,Kr,Xe, etc) in these case 1 mole of gas ay STP will have mass equal to their gram atomic mass.

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer

i think its 100

i hope this !