Word Problem
Weights of atoms and molecules are measured in atomic mass units(u).
A molecule of C2H6(ethane) is made up of 2 Carbon atoms and 6 hydrogen atoms and
weighs 30.07 u. A molecule of C3H8
(propane) is made up of 3 carbon atoms and 8 hydrogen atoms and weighs
44.097 u. Find the weights of a carbon atom and a hydrogen atom.
| Form 2
equations to solve the problem. |
2C+6H=30.07 3C+8H=44.097 |
| Multiply
the top equation by 3 and the bottom equation by -2 so you are solving for H. |
6C+18H=90.21 -6C-16H=-88.194 |
| Next solve the equation for y. | 2H=2.016 H=1.008 |
| Put H back
into one of the original equations. |
2C+6(1.008)=30.07 2C+6.048=30.07 2C=24.022 C=12.011 |
Carbon has a weight of 12.011 u and
Hydrogen has a weight of 1.008 u.