Video Transcript
Which pair of compounds from the
following chemicals could be added to (NH4)2SO4 to make a fertilizer that provides
soil with the three elements required for plant growth? (A) K2SO4 and Na3PO4, (B) KNO3 and
Na2SO4, (C) NaCl and CaHPO4, (D) NH4Cl and Na2HPO4, (E) Ca(NO3)2 and NH4Cl.
Plants require specific nutrients
to grow, just like animals do. There’s many different elements
plants need for healthy growth. But the three elements plants often
can’t get except through fertilization are nitrogen, phosphorus, and potassium. Nitrogen is required for the
production of amino acids and therefore proteins. Phosphorus is needed to make
adenosine triphosphate, or ATP, which is important for cellular energy. Potassium aids in the
transportation of nutrients throughout the plant.
Since nitrogen, phosphorus, and
potassium are so important for plant growth, we often want to add these three
elements via fertilization. Fertilizers that contain all three
of these elements are called NPK fertilizers. In this question, we are
fertilizing a plant with ammonium sulfate. Ammonium sulfate contains the
element nitrogen. But it doesn’t have any phosphorus
or potassium. We need to figure out which
chemicals we can add to ammonium sulfate to make a fertilizer that has all three of
the important elements required for plant growth.
Since ammonium sulfate already has
nitrogen in it, we need to find chemicals that will add phosphorus and
potassium. We can go through each of the
chemicals in our answer choices to see which contain phosphorus and which contain
potassium. We can see that the only
combination of chemicals that has both phosphorus and potassium is answer choice
(A), potassium sulfate and sodium phosphate.
So the correct answer here is
answer choice (A). If we add K2SO4 and Na3PO4 to
(NH4)2SO4, we’ll have a fertilizer that provides the soil with nitrogen, phosphorus,
and potassium, the three elements required for plant growth.
