Question

You can use percent composition to calculate the number of grams of any element in a specific mass of a compound. How?

Answer 1

Percent composition is used to calculate the number of grams of each element in a mass of a compound by finding the percent by mass of each element and then applying this percentage to the mass of the sample.

Step-by-step explanation:

To calculate the number of grams of any element in a specific mass of a compound you can use percent composition. The percent composition indicates the percent by mass of each element within a compound. Here's how you would perform the calculation:

• First, determine the percent by mass of the element in the compound. This is done by dividing the mass of the element in one mole of the compound by the molar mass of the entire compound and multiplying the result by
  `100%.`
• Next, take the percent composition and apply it to the mass of the sample you're interested in. For example if you have a
  `100-gram` sample and an element makes up
  `40%` of the compound by mass, then the element contributes
  `40 grams` to the sample.
• If the sample isn't
  `100 grams` , multiply the percent composition (as a decimal) by the mass of the sample you have. For instance, if you have a
  `50-gram` sample and the element comprises
  `30%` by mass it would contribute
  `15 grams` to the sample (
  `0.30 x 50` ).

Note that when calculating percent compositions, the sum of the percentages of all elements in a compound will always add up to
`100%`.