Let's tackle this question together. I've divided my answer into two parts, if you want the quick answer skip the first part.
In the English language we have several words to refer to the reason why an action happened/happens. there are also a couple of words and structures to refer to the purpose of an action, Let's review them together:
REASON: because, as a result of, on account of, due to, as, since,etc.
PURPOSE: so (that), So as to, (in order) to, etc.
Let's look at some examples:
Charles went home so that he would see his family.
Charles stayed up late in order to finish the project.
In these examples, the bold portion of the sentence shows the purpose of his action.
Charles went home since his mom wanted him home for Christmas
Charles worked late because his boss called a meeting
In the examples above, the bold part shows the reason why he did those actions.
Cause: His mom wanted him home
Effect: he went home.
In a nutshell,
purpose: the reason for why something is done
reason: the cause/justification for an action or event.
Consider a dam. The purpose of the dam was to retain water for irrigation. The reason the dam broke was because the water got too high.
“Reason” concerns cause and effect. “Purpose “ deals with conscious intent. Therefore, So that doesn't mean as a result of
Now, with that out of the way, let's see if we can use and instead of so that.
consider these examples:
eat this cake and you will regret it!
Visit Spain and you will enjoy the beautiful scenery.
Call him and he will deliver the package to your door.
in all of these examples, the italic portion is telling us about the result of the action.
DO A, *B* will happen.
there's a great deal of certainty with each one, as if with the completion of A, B will most definitely take place.
Keep in mind, a sentence like:
Touch this cake so that you will regret it!
Doesn't make much sense, you wouldn't normally tell someone to do something with the purpose of making them regret it! So, in this instance we can't replace and with so that. Compare it with this:
eat your vegetables so that you'll have a strong body.
The sentence above is perfectly valid.
Therefore, we realize that and and so that are not always interchange.
in the other two examples, you could replace and with so that. Although keep in mind the meaning changes slightly:
Visit Spain so that you can enjoy the beautiful scenery. (visit Spain with the intention of enjoying the beautiful scenery - the purpose for your visit is/should be enjoying the beautiful scenery)
Visit Spain and you will enjoy the beautiful scenery (really strong, if you visit Spain you will without a doubt enjoy the scenery)
use and when you want to say if action A is done, Action B will most definitely take place or have certain result.
use so that (and by extension in order to) to talk about the purpose of an action.
use because (and by extension, other words I mentioned in the first part of my answer) to talk about the reason, cause or justification of an action.