Question

If 15.1 moles of carbon dioxide, CO2, was produced, how many grams of water was also produced?C6H12O6 (s) + 6 O2(g) → 6 CO2 (g) + 6 H2O (g)

Answer 1

Step 1 - Finding the stoichiometry of the reaction

The given reaction is:

`C_6H_(12)O_(6(s))+6O_(2(g))\to6CO_(2(g))+6H_2O_((g))`

We can find the stoichiometry of the reaction by the bigger numbers that come before the formula of each substance:

1 mole of C6H12O6 react with 6 moles of O2 thus producing 6 moles of CO2 and 6 moles of H2O

Step 2 - Converting the relation in moles to a relation in grams

We can convert this relation in moles to a relation in grams by multiplying the number of moles of each substance by its molar mass. Note that the exercise only asks us about water and CO2.

We can thus rewrite the statement in step 1 as:

whenever 6 moles of CO2 are produced in this reaction, we also produce 6 moles of water

The molar mass of water is 18 g/mol, thus, in grams, we produce, in this reaction:

`H_2O\to6*18=108\text{ g}`

Finally, we can state that:

whenever 6 moles of CO2 are produced in this reaction, we also produce 108 g of water

Step 3 - Discovering how many grams of water were formed

We can now set a proportion to discover how many grams of water would be formed if 15.1 moles of CO2 were also produced:

`\begin{gathered} 6\text{ moles of CO2 are produced with ---- 108 g of water} \\ 15.1\text{ moles of CO2 are produced with --- x} \\ \\ x=(15.1*108)/(6)=271.8\text{ g of water} \end{gathered}`

Therefore, 271.8 g of water would be produced in this reaction.