Neutralizing a basic reaction with HCl

[reising1]

Homework Statement

I am reacting methyl salicylate with sodium hydroxide to produce salicylic acid. However, first it is important to add acid to neutralize the very basic solution.

My question is, when determining the amount of HCl to add, do I need to take into consideration the methyl salicylate? Or am I just basing it off of the amount of sodium hydroxide I add?

Homework Equations

The Attempt at a Solution

 

[mrmiller1]

Can you simply add the HCl drop-wise until your pH probe or paper yields a neutral result?

 

[reising1]

No, I am supposed to calculate the number before coming to lab.

 

[Borek]

Think what reactions take place and what substances are present in the mix when you start adding acid. This is just a simple stoichiometry.

The only tricky part is whether you want to just neutralize, or to acidify to protonate salicylic acid. That depends on the procedure you are going to follow.

 

[reising1]

So if I am just trying to neutralize, and if I have 120 mmoles of NaOH, then I would need 120 mmoles of HCl to neutralize, right?

 

[Borek]

IFF you have 120 mmoles of NaOH - yes.

 

[NascentOxygen]

Is this any different to just starting with a saline solution? Perhaps with 2 or 3 drops of acid or alkali added to tilt the pH one way or the other?

 

[Borek]

First, you won't get pH high enough. Second, write reaction equation.