What volume does 0.465 mol of gas occupy at STP? (Answer in 4 digits)

Air can be considered a mixture. which statement does not explain why?

How many oxygen atoms are there in 3.15 moles of hcl manganese (iv) oxide, mno2

4.25g sample of solid ammonium nitrate dissolves in 60.0g of water in a coffee-cup calorimeter, the temperature drops from 22.0 c to 16.9 c. assume that the specific heat of the solution is the same as that of pure water. calculate delta(h) (in kj/mol nh4no3) for the solution proces.