All AP Chemistry Resources
Example Question #1 : Naming Compounds
What is the IUPAC name for ?
is a saturated hydrocarbon with an organic functional group, , or alcohol.
is propane, so we will remove the "e" from the end of that name and add the suffix "ol" to denotate an alcohol, so the correct answer is propanol.
Propenol is propanol with a double bond in the hydrocarbon chain. Ethanol is a saturated two-carbon chain with an alcohol functional group.
Example Question #2 : Naming Compounds
Name the following compound: .
Covalent non-metal/non-metal compounds are named by taking the name of each element and appending the apropriate greek prefix to indicate the number of each atom present—in this case, di- for two and tetra- for four. The end of the more electronegative element is substituted with "ide". This gives the name of dinitrogen tetraoxide.
Example Question #3 : Naming Compounds
What is the systematic name for ?
Cesium (I) sulfate
Cesium sulfur tetraoxide
Ionic compounds are named by naming the cation followed by the anion. Since the cation, cesium, is an alkali metal the oxidation state, should not be specified. Alkali metals will always have an oxidation state of 1. The anion, , is sulfate. Together, the full name of the compound is cesium sulfate.
Example Question #4 : Naming Compounds
Name the following compound:
Zinc chloride tetroxide
The compound's name is zinc perchlorate. With the addition of a fourth oxygen atom to the molecule, chlorate , we follow the polyatomic ion naming rules and add a per- to the molecule's name, giving us perchlorate. When bonded ionically to a zinc cation , the resulting ionic compound is called zinc perchlorate.
Example Question #5 : Naming Compounds
What is the formula of hydroiodic acid?
is the correct formula because, following IUPAC acid naming rules, when combining a hydrogen cation with an anion that consists of only one element (in this case iodide), one drops the -ide ending, adds an -ic ending and adds a hydro- prefix. Other examples would be hydrochloric acid and hydrofluoric acid .
Example Question #6 : Naming Compounds
A student named a certain organic molecule 2-(1-methylbutyl)-3-isopropylbutane. While this name may give the possibility of correctly drawing the molecule, it does not follow correct IUPAC naming guidelines. What is the correct name of this molecule?
While the student's description of the location and size of the sidechains is correct, he/she failed to recognize the longest parent chain, it being the eight-carbon string which encompasses what he/she named isopropyl- and pentyl-. The resulting octane molecule has four methyl- substituents at the 2, 3, 4, and 5 positions.
Example Question #7 : Naming Compounds
Which of the molecules above does not match its molecular formula?
While it is tempting to think that butane and isobutane, because of their structural differences would have different numbers of of hydrogens, they are in fact constitutional isomers, and have the same molecular formula. Both butane and isobutane have four carbons and ten hydrogens, although butane's carbons and hydrogen's are arranged
and isobutane's are arranged
A good rule of thumb for the formulas of simple hydrocarbons is:
Example Question #8 : Naming Compounds
Which of the following is a correct name for the compound, ?
I: Potassium bicarbonate
II: Potassium percabonate
III: Potassium hydrogen carbonate
I and III
II and III
I and III
Because the ion, , is correctly referred to as both bicarbonate and hydrogen carbonate, the correct names for the compound in question are both potassium bicarbonate and potassium hydrogen carbonate.
Example Question #9 : Naming Compounds
Which of these is not the IUPAC name for the indicated molecule?
Because the polyatomic ion from which the acid, , is derived is perchlorate, , the resulting acid is named perchloric acid. The naming protocol is to use the -ic suffix for acids derived from polyatomic ions ending in -ate, while using the -ous suffix for acids derived from polyatomic ions ending in -ite.
Example Question #21 : Compounds
What is the name of the compound with the chemical formula ?
All of the incorrect options have prefixes or suffixes associated with polyatomic ions "hypo," "per," "ite," and "ate". Since is not an ion (it does not have a charge), it must just be a covalent compound. Therefore, use the prefixes reserved for covalent compounds to name it.