Difference between revisions of "Relative Formula Mass"
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===About Relative Formula Mass===  | ===About Relative Formula Mass===  | ||
| + | : The '''relative formula mass''' is used to find the [[mass]] of a [[molecule]] needed to perform a complete [[Chemical Reaction|reaction]] with another [[chemical]].  | ||
| + | |||
| + | ===Calculating Relative Formula Mass===  | ||
: '''Relative formula mass''' can be calculated from the [[Chemical Formula|chemical formula]] of the [[molecule]] and the [[Relative Atomic Mass|relative atomic mass]] of the [[element]]s.  | : '''Relative formula mass''' can be calculated from the [[Chemical Formula|chemical formula]] of the [[molecule]] and the [[Relative Atomic Mass|relative atomic mass]] of the [[element]]s.  | ||
| − | :   | + | |
| + | {| class="wikitable"  | ||
| + | |-  | ||
| + | | style="height:20px; width:200px; text-align:center;" |Find the '''relative formula mass''' of O<sub>2</sub>.  | ||
| + | | style="height:20px; width:200px; text-align:center;" |Find the '''relative formula mass''' of CO<sub>2</sub>  | ||
| + | | style="height:20px; width:200px; text-align:center;" |Find the '''relative formula mass''' of C<sub>6</sub>H<sub>12</sub>O<sub>6</sub>  | ||
| + | |-  | ||
| + | | style="height:20px; width:200px; text-align:left;" |  | ||
| + | [[Relative Atomic Mass]] of [[Oxygen]] = 16g  | ||
| + | |||
| + | No. [[Oxygen]] [[atom]]s = 2  | ||
| + | |||
| + | [[Relative Formula Mass]] of O<sub>2</sub> = 16x2  | ||
| + | |||
| + | [[Relative Formula Mass]] of O<sub>2</sub> = 32g  | ||
| + | |||
| + | | style="height:20px; width:200px; text-align:left;" |  | ||
| + | [[Relative Atomic Mass]] of [[Carbon]] = 12g  | ||
| + | |||
| + | [[Relative Atomic Mass]] of [[Oxygen]] = 16g  | ||
| + | |||
| + | No. [[Carbon]] [[atom]]s = 1  | ||
| + | |||
| + | No. [[Oxygen]] [[atom]]s = 2  | ||
| + | |||
| + | [[Relative Formula Mass]] of CO<sub>2</sub> = 12x1 + 16x2  | ||
| + | |||
| + | [[Relative Formula Mass]] of CO<sub>2</sub> = 44g  | ||
| + | |||
| + | | style="height:20px; width:200px; text-align:left;" |  | ||
| + | [[Relative Atomic Mass]] of [[Carbon]] = 12g  | ||
| + | |||
| + | [[Relative Atomic Mass]] of [[Hydrogen]] = 1g  | ||
| + | |||
| + | [[Relative Atomic Mass]] of [[Oxygen]] = 16g  | ||
| + | |||
| + | No. [[Carbon]] [[atom]]s = 6  | ||
| + | |||
| + | No. [[Carbon]] [[atom]]s = 12  | ||
| + | |||
| + | No. [[Oxygen]] [[atom]]s = 6  | ||
| + | |||
| + | [[Relative Formula Mass]] of C<sub>6</sub>H<sub>12</sub>O<sub>6</sub> = 12x6 + 1x12 + 16x6  | ||
| + | |||
| + | [[Relative Formula Mass]] of C<sub>6</sub>H<sub>12</sub>O<sub>6</sub> = 180g  | ||
| + | |}  | ||
Revision as of 19:18, 2 January 2019
Contents
Key Stage 4
Meaning
The relative formula mass (Mr) of a molecule is the mass of one mole of molecules.
NB One mole is 6.02x1023 molecules.
About Relative Formula Mass
- The relative formula mass is used to find the mass of a molecule needed to perform a complete reaction with another chemical.
 
Calculating Relative Formula Mass
- Relative formula mass can be calculated from the chemical formula of the molecule and the relative atomic mass of the elements.
 
| Find the relative formula mass of O2. | Find the relative formula mass of CO2 | Find the relative formula mass of C6H12O6 | 
| 
 Relative Atomic Mass of Oxygen = 16g Relative Formula Mass of O2 = 16x2 Relative Formula Mass of O2 = 32g  | 
 Relative Atomic Mass of Carbon = 12g Relative Atomic Mass of Oxygen = 16g Relative Formula Mass of CO2 = 12x1 + 16x2 Relative Formula Mass of CO2 = 44g  | 
 Relative Atomic Mass of Carbon = 12g Relative Atomic Mass of Hydrogen = 1g Relative Atomic Mass of Oxygen = 16g Relative Formula Mass of C6H12O6 = 12x6 + 1x12 + 16x6 Relative Formula Mass of C6H12O6 = 180g  |