Question

Mia has a 32.0 g sample of Fe(OH)3 for the investigation purpose. How many grams of oxygen be recovered from the sample?3.6 g21.6 g7.2 g14.4 g

Answer 1

INFORMATION:

We know that:

- Mia has a 32.0 g sample of Fe(OH)3 for the investigation purpose.

And we must find how many grams of oxygen are recovered from the sample

STEP BY STEP EXPLANATION:

To find the amount of gram of oxygen, we must:

1. Calculate the percent of oxygen in compound

- Find the molar mass of the compound

$\begin{gathered} 1mol\text{ }Fe=1\times55.85\frac{g}{mol}=55.85\frac{g}{mol} \\ 3mol\text{ }O=3\times16.00\frac{g}{mol}=48.00\frac{g}{mol} \\ 3mol\text{ }H=3\times1.008\frac{g}{mol}=3.024\frac{g}{mol} \\ Molar\text{ }mass\text{ }Fe(OH)_3=106.87\frac{g}{mol} \end{gathered}$

- To find the percent by mass, divide the part by the whole and multiplying by 100.

$\frac{48.00g\text{ }O}{106.87\text{ }Fe(OH)_3}\times100\%=44.91\%$

2. Multiply the starting mass by the percent of the desired element.

$32.0g\text{ }Fe(OH)_3\times0.4491=14.4g\text{ }O$

Finally, 14.4 g of oxygen are recovered from the sample.

ANSWER:

14.4 g