Question

How many grams of `N_2` are required to completely react with 3.03 grams of `H_2` for the equation `N_2 + 3H_2 -> 2NH_3`?

Answer 1

`7.01"g"`

Explanation:

Notice the coefficients of `N_2` and `H_2`.

Since the equation has an `N_2` and `3H_2`, `3` times as many moles of `H_2` will be used as `N_2` assuming a complete reaction.

Since we're given the mass of `H_2` being used, we can divide that by the molar mass of `H_2` to determine how many moles of `H_2` will be consumed. We can divide that mole amount by `3` to find how many moles of `N_2` the reaction will use, and multiply that by the molar mass of `N_2` to find how many grams we should use.

`3.03"g"H_2xx(1"mol"H_2)/(2.02"g"H_2)xx(1"mol"N_2)/(3"mol"H_2)xx(14.02"g"N_2)/(1"mol"N_2)=7.01"g"N_2`