Practice!

Sample Problem

Match the following compound names with their chemical formula. Fill in the blank with the correct letter (eg: “A”).

A.     Nitrate

B.      Nitrite

C.      Nitrogen gas

D.     Ammonium

N2

NH4+

NO2-

NO3-

Solution

The answers are as follows: C, D, B, A.

Remember the different tricks to help you memorize these. The phrase “Nitrogen gas” has two “n”s in it, so the formula is N2. “Ammonium” has four vowels in it, so the formula is NH4+. “Nitrite” has two vowels in it, so the formula is NO2-. “Nitrate” has three vowels in it, so the formula is NO3-