Question

For the reaction `2HNO_3 + Mg(OH)_2 -> Mg(NO_3)_2 + 2H_2O`, how many grams of magnesium nitrate are produced from 8 moles of water?

Answer 1

`593.2 " g "Mg(NO_3)_2`

Explanation:

We can use stoichiometry to find the moles of `Mg(NO_3)_2` and then the respective grams of `Mg(NO_3)_2`.

If 8 moles of water are produced, we can find out how many moles of `Mg(NO_3)_2` are produced using this equation:

`(8 " "cancel("mol "H_2O))/1*(1 " mol " Mg(NO_3)_2)/(2" "cancel("mol "H_2O))=4" mol "Mg(NO_3)_2`

From here, we can use ratios to convert to the grams of `Mg(NO_3)_2`:

`(4 " "cancel("mol "Mg(NO_3)_2))/1*(148.3 " g " Mg(NO_3)_2)/(1 " "cancel("mol " Mg(NO_3)_2))=593.2 " g "Mg(NO_3)_2`

(You can get the molar mass of `Mg(NO_3)_2` by referencing a periodic table and summing the masses of each element in the compound.)