# Mixing of Strong acid and Weak acid

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1. Feb 2, 2017

### Jay the EE

Hi! I wanna clarify what will happen if you mix two acids. One is stronger and One is less stronger. What will be the pH level result? for example if the acid is the juice from lemon which is at 2.0 be mix with orange ph level of 3.0, will it be greater than less than 2.0? or will it be 2.5?

Kindly site some references of the basis of the answers :D badly needed it for my research. Im not a chemistry student. so if you can explain it in a simple way then its better. Thanks guys!

PS: if you have list of ph level charts all of fruits and vegetables. I find contradicting tables found on google. I am currently basing my data on the FDA files

2. Feb 2, 2017

### Staff: Mentor

There is not enough information to answer the question, as it depends on relative strengths of the acids, their concentrations and volumes mixed. In general the pH of the mixture will be somewhere between original pH values.

I strongly suggest you read about the equilibrium calculations, acid dissociation constant and related things, this is the only reasonable approach to solving this type of problems. It is not difficult if you have some basic math skills.

There is no such thing as a definitive list of "pH of a fruits and vegetables". Fruits are not identical. One apple can be sour, the other can be sweet, and the pH difference can be quite large. At best you can get ranges of pH.

3. Feb 2, 2017

### Jay the EE

Thanks for the info about the pH level thing.

is there a theory that could say that in general the mixture will be between the original ph values? is there a book or a reliable online source you can share?

What im really trying to do is to for example, extract the juice of tomatoes and lime, then combine then. I just need to know or atleast assume the result based on theory. Im having a hard time looking for references :( i badly needed them for my research proposal. Need a theory to back up the idea of being able to mix acid with another acid.

Anyway, will the nernst equation be helpful with my problem?

4. Feb 2, 2017

### Jay the EE

to be honest the idea for the research i am currently doing is using the wasted fruits and veggies as electrochemical energy source and set it up like galvanic cell to generate voltage. I need to learn the possibility of adding acids to acids and the resulting ph level since voltage will be dependent with the ph level.

5. Feb 2, 2017

### Staff: Mentor

Any General Chemistry book is a reference - even if they won't have this particular answer ready.

When it comes to calculating pH (which is what the problem really is about) you can try to read http://www.chembuddy.com/?left=pH-calculation&right=toc

You can't find a reference for this particular problem as nobody bothers with such things. You are asking for a reference saying that 123*456=56088, instead of a reference explaining how the multiplication works.

No, Nernst equation deals with redox systems, not acid/base reactions.

I really, really suggest you start with back chemistry, GenChem101 is what you need.

6. Feb 2, 2017

### Staff: Mentor

pH itself can't be a source of energy.

Drying and burning would work much better.

7. Feb 2, 2017

### Jay the EE

oh yeah but i read on some sites and research that the more acidic the better it will serve as an electrolyte for the battery cell set up.

So if i try to heat up the extracted juice, would it be yielding better results?

8. Feb 2, 2017

### Staff: Mentor

This question is so open and so ambiguous it doesn't make any sense.

There are no shortcuts. If you want to deal with systems with a serious chemistry behind, you need to know the chemistry well enough.