Chemistry Help!

[Ash1994]

Camphor is a white solid which was used to make the early plastic celluloid. Camphor contains
the same percentage by mass of hydrogen and oxygen.
What is the molecular formula of camphor?
A C10H6O6
B C10H8O
C C10H16O
D C10H10O2

15 Ammonium sulfate in nitrogenous fertilisers in the soil can be slowly oxidised by air producing
sulfuric acid, nitric acid and water.
How many moles of oxygen gas are needed to oxidise completely one mole of ammonium
sulfate?
A 1
B 2
C 3
D 4

Can you like explain them as well please

 

[maarij]

the first question says percentage by mass...so u add up the mr. and divide the mass of hydrogen and oxygen contained in the molecule by the molecules mr. if they are both equal to each other...u have ur answer...while the second is pretty straight forward....write out the equation and balance the Os on either side of the equation...