Answer: When a substance is pure, it is composed of one type of molecule. For example, table salt is only composed of (more or less) salt molecules, while seawater has water and salt molecules. A more complicated example of a non - pure substance is soil. It has many different types of nutrients and compounds.
I believe dimensional analysis
A. Fireworks exploding is the answer
1 mole of N2 produces 2 moles of NH3
OR...
14 x 2 grams of N2 produces 2(14 +3) grams of NH3
1 gram of N2 produces 34/28 grams of NH3
therefore, 56 grams produce (34/28 )x 56 =68 grams of NH3
the answer thus would be 68 grams of NH3
Because medications contains chemicals, it would dissolve into the water and not only would it pollute the water, it could flow out into areas where people are exposed to these waters.