Video Transcript
What is the name of the salt represented in the following diagram? (A) Sodium carbonate, (B) sodium phosphate, (C) potassium acetate, (D) potassium oxide, or (E) potassium carbonate.
The diagram given represents a salt which is an ionic compound made up of cations and anions. The question is asking us to identify the correct name of the salt shown in the diagram. To determine the name of a salt, we take first the name of the cation, which is the positively charged ion, and then we take the name of the anion, which is the negatively charged ion. The name of a cation is the same as the name of the element from which it is formed, while the name of an anion takes the root of the element name from which it is formed and adds I-D-E as the ending. So, let’s identify the names of the ions from the diagram to determine the name of this salt.
The positive charge shown here tells us that this is the cation present in the salt. This chemical symbol of K one plus represents the potassium ion. So, the name of this salt begins with the cation name potassium. Next, let’s determine the name of the anion. The negative charge shown here tells us that this portion of the diagram is the anion. This anion is a polyatomic ion, which means it is a unit of covalently bonded atoms that have a charge overall and together behave as a single ion.
This polyatomic ion has a carbon covalently bonded to three hydrogens and another carbon. This carbon is bonded to two oxygen atoms and overall has a charge of one minus. This gives us the condensed formula of CH3COO one minus. Or we might also write the chemical formula of this poly atomic ion as C2H3O2 one minus. This polyatomic anion is called the acetate ion. And because it is not a single element, we do not need to change the ending of this anion name.
It is worth noting that in names of salts, polyatomic ions keep their name exactly as is whether they are cations or anions. So, the name of this salt overall is the name of the cation and anion together, which gives us potassium acetate. So, the name of the salt represented in the following diagram is answer choice (C) potassium acetate.
