Here we come to our second way of determining purity of a substance /identifying what that substance is.*
TLC is extremely helpful and can be much faster than other ways of determining whether or not your product is pure or whether other side products have formed/starting material is still present.
Here’s some fun resources you can use!
A lovely almost-but-not-quite exhaustive look at TLC. Check out those charts!
*What do you think the first way is?