For each of the following examples, decide whether it would be better to use the
term molecule or formula unit.
a. K2SO3 b. H2SO3 c. CCl4 d. NH4Cl
a and d; formula unit
a) formula units
b) molecules
c) molecules
d) formula units
To decide whether it would be more appropriate to use the term "molecule" or "formula unit" for each of the given examples, we need to consider the type of compound.
a. K2SO3: In this case, we have a compound composed of multiple elements (potassium and sulfur) and the presence of a subscript indicates that there are multiple atoms of each element. Since it is a covalent compound made up of multiple atoms sharing electrons, the more suitable term to use would be "molecule."
b. H2SO3: Similar to the previous example, we have a compound with multiple elements (hydrogen, sulfur, and oxygen) and multiple atoms of each element. Thus, it is also a covalent compound, and "molecule" would be the appropriate term.
c. CCl4: In this case, we have a compound consisting of carbon and chlorine atoms. However, the absence of subscripts indicates that there is only one atom of each element. Since it is a covalent compound composed of individual atoms bound by covalent bonds, we can still say that "molecule" is the more suitable term.
d. NH4Cl: Unlike the previous examples, this compound contains both an element (chlorine) and a polyatomic ion (ammonium, NH4+). The presence of the ion suggests that the compound is ionic in nature. Ionic compounds do not exist as discrete molecules but rather as a regular arrangement of ions in a crystal lattice. Therefore, the term "formula unit" would be more appropriate for NH4Cl.
In summary, for the given examples, the more suitable term to use would be "molecule" for a, b, and c, and "formula unit" for d.