What is the chemical name of the compound NH4SCN?
(1) ammonium thiocyanate
(2) ammonium cyanide (3) nitrogen hydrogen cyanide
(4) nitrogen hydrogen sulfate
Answer: (1) ammonium thiocyanate
Explanation: In order to name a compound, we must first figure out whether it is ionic or covalent. Ionic compounds can be divided into three categories: metal + nonmetal, meta+ polyatomic ion, polyatomic ion+ polyatomic ion, polyatomic ion + nonmetal. Covalent compounds consist of 2 nonmetals.
What is a polyatomic ion? It is an ion consisting of 2 or more elements. The reference table has Table E, Selected Polyatomic ions. If we look at Table E, we can see that NH4+ is a polyatomic ion and so is SCN-. Since the compound consists of two polyatomic ions, it is indeed an ionic compound. To name an ionic compound consisting of two polyatomic ions, we simply name the first polyatomic ion followed by the name of the second polyatomic ion. We can find polyatomic ion names in Table E. Therefore, the name for NH4SCN is (1) ammonium thiocyanate.
For more chemistry help, please contact Transformation Tutoring by calling us at 646-407-9078. Our founder and chemistry tutor, Mayya, has been tutoring chemistry for the past 9 years with great results.