[ThePeople]

I am going to perform a neutralization. Im going to simulate stomach acid by adding 0.1M HCl so the pH in my created stomach acid/gastric acid is 1.

My lab is about acid reflux, NH3 will be my antacid. The molarity of my NH3 will probably 0.1 (not sure yet, i have not been given the substances yet)

My questions are:

1. HCl is aqeous so that means i should just arbitarely pour in perhpas 10 dl into an E-Colv/bowl? Will that work as a stomach acid?

2. What is regarded at the maximum of pH that a stomach should have? Should i stop adding Nh3 when the pH is at 2?

3. My pH calculator/meter will have to be "calibrated", how do I calibrate a pH calculator?

4. Is there anything else I should mention or include such as a pH-graph or perhaps mention moles etc? How do I make a pH-graph then?

Many thanks in advance,
ThePeople

P.S. I have looked up many of these things I've mentioned but I didn't understand them so well so please explain in the most simplistic way possible.

[Borek]

It is not clear to me what the experiment is, so I can't help you much - you need to post more information.

When it comes to pH meter calibration I can point you in the right direction:

http://www.ph-meter.info/pH-electrode-calibration

As you are going to measure low pHs, you may need a pH 1.00 calibrating solution.

[ThePeople]

It is not clear to me what the experiment is, so I can't help you much - you need to post more information.

When it comes to pH meter calibration I can point you in the right direction:

http://www.ph-meter.info/pH-electrode-calibration

As you are going to measure low pHs, you may need a pH 1.00 calibrating solution.

Basically I am going to create stomach acid but I am not so sure on how I do that. What i have is a bottle of 0.1M HCl(aq), is that already by itself equivalent to stomach acid?

Then I am going to neutralize it with a weak base(NH3). Here i am supposed to take notes. What should i take notes on? Amount of NH3 to raise pH by 1 or is it something else i should look for? I googled around a little and i saw pH graphs/titration curves, should i add them in my notes?

Should I expect salts to be formed? Because NH3 + HCl = NH4Cl

I just wanted to be prepared for whatever happens when I add NH3(aq) to HCl(aq) because this is my most important experiment and I need to be well prepared.

Thanks for your link on pH calibration.

Sincerely,
ThePeople

[Borek]

If memory serves me well pH of th gastric acid is around 2, so 0.1M solution seems to have too high concentration.

What is solubility of NH₄Cl?

From what you wrote it will be just a titration curve.

[ThePeople]

If memory serves me well pH of th gastric acid is around 2, so 0.1M solution seems to have too high concentration.

There is only 0.1M solution available and my teacher said it was okay.

What is solubility of NH₄Cl?

According to this youtube clip:
http://www.youtube.com/watch?v=J2G8qkdEVa8

NH4Cl will be a gas... Why? Is it dangerous? If I would use NH3 to ease the pain caused by acid reflux, how would the gas (NH4Cl) affect me? Badly or nothing?

Anyway, thank you for your help.

Sincerely,
ThePeople

[fledarmus]

You need to do more research on the compounds you are planning to use.

Ammonia (NH₃) is a gas, and is toxic. HCl is also a gas. Both are usually handled in water solution, but there will be some of each in the vapor phase over the solution. The white smoke that you see in the youtube clip is the solid ammonium chloride that forms when HCl reacts with ammonia in the air. It is actually a very fine dust.

Ammonium chloride (NH₄Cl) is a solid and not a gas. If you heat it up enough, it will not melt or boil, but will decompose back into ammonia and HCl gas.

Please read a lot more on these compounds before trying to handle them. In particular, the idea of drinking an ammonia solution as an antacid is scary.

You might want to look here http://en.wikipedia.org/wiki/Gastric_acid for the composition of stomach acid and the mechanism for its production and the body's own ways of neutralizing it. Perhaps that will explain why sodium bicarbonate or similar compounds are usually used as antacids.

[Borek]

Note that solutions used in the clip are probably much more concentrated than the solutions you will be using.