finding reacting masses from equations

  • 0 votes

12.2g of magnesium reacts completely with oxygen gas.
Calculate the mass of oxygen consumed during the reaction and the mass of magnesium oxide produced.

Posted Thu 13th September, 2012 @ 19:34 by mercymime

2 Answers

  • 1 vote

hey i think you have to find out the mass of O2 used first and then multiply the mass of magnesium and the total mass of o2 used and it should give you the answer...

hope that helps... ;)

if i'm wrong please correct me;) but i'm pretty sure that what you're meant to do.. that's what i'd do..:)***

Answered Thu 13th September, 2012 @ 19:43 by Muzz :P
  • 0 votes

the right thing to do is to first write the balance equation for reaction which is

2Mg+O2---- 2MgO

mole ratio is 2:1:2

Ar of Mg is 24.3

Ar of MgO is 40.3

then the next thing to do is find the mole of Mg which is 12/24.3=0.493

then 1/2 x0.493=0.247

0.247 x 32=7.9g

that the answer

Answered Thu 13th September, 2012 @ 20:19 by mercymime