# How do we use the molar mass of Oxygen to solve this stoichiometry problem?

##
For the reaction represented by the equation #CX_4+2O_2=>CO_2+2X_2O#

*where *#"X"# is an unknown element

9g of #CX_4# completely reacts with 1.74g of Oxygen. What is the approximate molar mass of #X# ?

For the reaction represented by the equation

*where #"X"# is an unknown element*

9g of

##### 1 Answer

The approximate molar mass of

#### Explanation:

Let

The balanced equation is

**Step 1. Calculate the moles of #"O"_2#**

**Step 2. Calculate the moles of #"CX"_4#**

**Step 3. Calculate the molar mass of #"CX"_4#**

**Step 5. Calculate the molar mass of #"X"#**