how many mol is 29% hcl?

Question

I realize this is 1st sem chem stuff, but that was 20yrs in the rear view mirror, and I have to explain how to adjust the pH in the pool to my wife. I want to put a simple spreadsheet together for her so she knows how much acid to add to reduce the pH in an 8700 gallon pool. TIA

Cory

Answer 1

To solve this you need to know two things, the density of the acid and the molar mass of Hydrogen Chloride.
The molar mass of HCl is easy to find, it is 36.46 g/mol.

You could assume that 29% [by weight] HCl acid has the same denisty as water and get reasonable results, but because I just happen to have a CRC handbook of Chemistry and Physics handy, I looked it up for you.
Although it does not list a figure for 29% HCl, but it does list 28% and 30% HCl, so taking the average will give us a pretty good estimate.
29% HCl aqueous solution has a density of about 1.1442 g/mL.

Now, to find the concentration in terms of molarity of the acid, assume you have a sample of 100 grams.
If you have 100 grams of something that is 29% HCl, that meas you have 29 grams of HCl. 29 gams of HCl = .795 moles.
From the density of the solution, we know this 29 g of HCl is dissolved in 87.4 mL of solution.

Molarity is the number of moles of the solute in liters of solvent, so this would be,
Molarity = .795 moles / .0874
Molarity= about 9.1 Molar

Answer 2

Firstly, y use hydrochoric acid in a pool, the better is the hypocholride, NaOCl for that purpose,
29% by weight means 29 g of acid and 71 g of water,
the molecular weight of HCl is 36.5 g, so the number of moles is 29 divided by 36.5 the result is the number of moles of HCl in each 100 g of solution.

Answer 3

I FORGET THIS STUFF. YOU HAVE TO MAKE THE TRIANGLE. MAYBE USED AVOGADROS #. JUST BRING A SAMPL OF THE WATER INTO POOL PLACE FOR TESTING AND THEY'LL TELL YA WHAT TO ADD. THE TEST STRIPS WORK GOOD.

Answer 4

29% HCl is 0.795378249 moles

;)

Answer 5

I have a mole?