Question

Easy steps to doing stoichiometry?

Answer 1

Let's take a simple example of water reacting to form hydrogen and oxygen. This is given as \[H_2O \rightarrow xH_2 + y O_2\] The number of moles on the left and right must be equal. We can write two equations to represent this.\[\left[\begin{matrix}\text{For Hydrogen} & 2 = 2x \\ \text{For oxygen} & 1 = 2y\end{matrix}\right]\]Therefore, x must be 1 and y must be 1/2. The stoichiometric equation becomes \[H_2O \rightarrow H_2 + {1 \over 2} O_2\]

If you give me a specific example, I can help you through it.

Answer 2

Ok, I know I have to balance first and all that.. But if I had for example..
\[C _{2}H_{6} + O_{2} \rightarrow CO_{2} + H_{2}O\]

Answer 3

I would balance and get
\[2C_{2}H_{6} + 7O_{2} \rightarrow 4CO_{2} + 6H_{2}O\]

Answer 4

And it's asking, what mass of CO_{2} is produced?

Answer 5

From the balanced equation, the mass of the CO2 can be calculated as follows:\[m ={ MM \over N}\]where MM is the molecular mass, and N is the number of moles. The molecular mass of CO2 is 44 and the number of moles if 4.
Therefore, 11 grams of CO2 are produced for every 2 moles of ethane.