Question

Mercury(II) oxide (HgO) decomposes to form mercury (Hg) and oxygen (O2). The balanced chemical equation is shown below.2HgO Right arrow. 2Hg + O2The molar mass of HgO is 216.59 g/mol. The molar mass of O2 is 32.00 g/mol. How many moles of HgO are needed to produce 250.0 g of O2?

Answer 1

Answer: 15.62 moles of $HgO$ are needed to produce 250.0 g of $O_2$

Explanation:

To calculate the moles :

$\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}$    

$\text{Moles of} O_2=\frac{250.0g}{32g/mol}=7.812moles$

$2HgO\rightarrow 2Hg+O_2$

According to stoichiometry :

1 mole of $O_2$ is produced from decomposition of =  2 moles of $HgO$

Thus 7.812 moles of $O_2$ will be produced from decomposition of  =$\frac{2}{1}\times 7.812=15.62moles$ of $HgO$

Thus 15.62 moles of $HgO$ are needed to produce 250.0 g of $O_2$