Final answer:
To find how many grams of N2 are made from 6.8 grams of NH3, convert grams of NH3 to moles, use the reaction stoichiometry to find moles of N2, and then convert moles of N2 to grams, which results in 5.59 grams of N2 being produced.
Step-by-step explanation:
The question asks how many grams of N2 are made when 6.8 grams of NH3 are reacted according to the equation 4 NH3 + 3 O2 -> 2 N2 + 6 H2O. First, we need to find the molar mass of NH3, which is 17.03 g/mol (14.01 for nitrogen and 1.01 for each of the three hydrogens). The molar mass of N2 is 28.02 g/mol (14.01 for each nitrogen). Then, we can convert the amount of NH3 to moles and use the stoichiometry of the given reaction to find the moles of N2 produced.
From the mass of NH3, we find:
6.8 g NH3 * (1 mol NH3 / 17.03 g NH3) = 0.399 mol NH3
According to the balanced equation, 4 moles of NH3 produce 2 moles of N2. Therefore, 0.399 moles of NH3 will produce:
0.399 mol NH3 * (2 mol N2 / 4 mol NH3) = 0.1995 mol N2
Converting this to grams:
0.1995 mol N2 * (28.02 g N2 / 1 mol N2) = 5.59 g N2
Therefore, 6.8 grams of NH3 produce 5.59 grams of N2.