Question

9. Determine the percent compositions for each of the following compounds. b. copper (I) oxide

Answer 1

The percent composition of Cu = 88.82%

The percent composition of O = 11.18%

Step-by-step explanation

Given:

Copper (I) oxide

What to find:

The percent compositions for each of the elements in the compound.

Step-by-step solution:

Step 1: The first step is to write the molecular formula of copper (I) oxide.

The molecular formula of copper (I) oxide is Cu₂O.

Step 2: Determine the total mass of copper (I) oxide.

From the periodic table, the atomic mass of (Cu = 63.546, O = 15.999)

Cu₂O = (2 x 63.546) + 15.999

Cu₂O = 127.092 + 15.999 = 143.091

Step 3: Determine the percent composition of copper.

Mass of Cu in Cu₂O = 127.092

Therefore, the percent composition of Cu is:

`\begin{gathered} Percent\text{ }composition\text{ }of\text{ }Cu=\frac{Mass\text{ }of\text{ }Cu}{Total\text{ }mass}*100\% \\ \\ Percent\text{ }composition\text{ }of\text{ }Cu=(127.092)/(143.091)*100\% \\ \\ Percent\text{ }composition\text{ }of\text{ }Cu=88.82\% \end{gathered}`

The percent composition of Cu = 88.82%

Step 4: Determine the percent composition of oxygen.

`\begin{gathered} Percent\text{ }composition\text{ }of\text{ }O=\frac{Mass\text{ }of\text{ }O}{Total\text{ }mass}*100\% \\ \\ Percent\text{ }composition\text{ }of\text{ }O=(15.999)/(143.091)*100\% \\ \\ Percent\text{ }composition\text{ }of\text{ }Cu=11.18\% \end{gathered}`

The percent composition of O = 11.18%