Victor S. answered • 04/04/19
Coaching students to understand chemistry more easily since 2007
When given a formula like this, an important question to ask is, what phase of matter is it?
That is, what state of matter is it?
Is this a solid? Or is it in solution?
Was it written as KCl (aq)? Remember what the (aq) means.
If the compound is in solution, then what would you actually find in the solution?
Would you find KCl molecules bonded together, floating among water molecules?
Or is KCl soluble in water?
If it is soluble, then what would happen to the potassium (K) and chlorine (Cl)?
Following solubility rules, we know that KCl is soluble.
Good, so this means that KCl would dissolve into K+ and Cl- ions. These are written as potassium ion and chloride ion.
What are ions? These are atoms with positive or negative charges.
Therefore, KCl is an ionic compound, also called a salt. This is not to be mistaken for table salt, NaCl.
To answer these kinds of questions, you need to know if the compound is ionic, not covalent, and if it is soluble in solution. :)
