40.0 L of oxygen were collected at 10°C and 758 mm of Hg.
Calculate its volume at STP

38.48 L. Good luck on your test :)

Explanation:

I clicked it and it was right.

2h2o2--> 2h2o + o2

this reaction is of the spontaneous decomposition of hydrogen peroxide down into water and oxygen.

add 2 molecules of hydrogen peroxide and 2 molecules of water. since oxygen is naturally diatomic, the total number of atoms of each element is now the same on both sides of the equation so it is balanced.

this may not be entirely correct but let me know.