[waefwaef]

Hey guys so I really need help on what molarity and what volume of HCl and NaOH to use to correctly test the neutralizing strength of acids. Im hoping to do 15-20 trials in total, each consuming 200mg(can be lower or higher) or so of crushed antacid tablets.

Given this, how much acid and what concentration would be ideal to titrate NaOH into HCl mixed with the antacid to measure the moles neutralized by the antacid? I'm really at a dilemma here because there is really only so much materials in our classroom. Currently I have 500mL of 0.1M HCl, but I diluted it with tap water and it may be too weak. I also need to standardize it(see below). The problem is of course if the HCl is too concentrated, I need too much NaOH to neutralize it, and if ita not concentrated enough then the tablet may push the pH of the solution past 7 by itself. Can anyone please give me any pointers? Thanks so much.

Also I need to standardize the NaOH with about 0.1M oxalic acid, and Im not sure how much I need to dilute it to measure the molarity of NaOH without wasting too much resources. Thank you guys again.

Also if it would help, the antacids Im using are Magnesium Carbonate+Alginic acid, Calcium Carbonate, Magnesium hydroxide and magnesium carbonate+calcium carbonate.

I tried working out how much I need by myself: http://i.imgur.com/dBMXCM3.jpg
These are my calculations for the estimated amounts of HCl and NaOH i need to experiment with 500mg of the tablet 20 times. However, Im not sure if these calculations are correct and if my teacher even has 400mg of naoh(he has lots of HCl, but NaOH is lacking), so is there some way I can reduce the amount I need to use? If I reduce the mass of the tablet used, it may be too hard to measure. Would reducing it to 250mg be too little? Please help I really need to get this sorted out soon.

[Borek]

Compare http://www.titrations.info/titrant-and-sample-volume

Just after skimming your work:

1. Never use tap water for analytical work. Distilled or equivalent (DI, RO) is the only way to go.
2. Mg(OH)₂ doesn't produce HCl, it requires HCl for the neutralization.
3. Where did you got the 0.4M (0.5M) concentration of HCl from?