- #1
ilii
- 39
- 1
Homework Statement
Calculate what mass of oxygen is required to completely combust 500.0g of gasoline. Assume that the gasoline contains only octane.[/B]
Homework Equations
My problem is... I don't know WHEN to apply sig figs. If this is a multi-step problem (i to iv in this case), do I apply sig figs starting in i)? if I do, then all of my future answers will be influenced by using sig figs early on. When I get to iv) I don't know if all my digits are OK or if they're all way off. Can someone please clean the sig figs up a bit and tell me when I need to apply them? thank you!
The Attempt at a Solution
i) 2C(8)H(18) +25O(2) = 16CO(2) +18H(2)O
ii) 500.0g/114.22852 = 4.377 mol of C(8)H18)
iii) z=4.377 *25/2
z=54.71488206 mol
z=55 mol of O(2)
iv) m(O(2))=55mol*31.9988g/mol
m(O(2))=1759.934 g[/B]
m(O(2))=1760 g