Hey Dr.Bob, I asked two days ago a question about a titration lab I had that you answered, but I still have one more question about that lab.
Here's the lab summary:
For my chemistry of solutions class, we had a titration lab where we titrated NaOH into an HCl + H2O mix. This was a preparatory titration for the next one consisting of the hydrolysis of ethyl acetate into acetic acid with H+ ions as a catalyst (in our case the HCl).
So now after I found the number of moles of NaOH and HCl (which is the same) from that solution, I had to find the mass of HCl in the 5mL HCl solution and the mass of 5mL HCl solution, which you helped me out with, but now I'm asked to find the mass of H2O in 5mL HCl solution.
For this, will I proceed like this?
Because of the equation:
HCl + NaOH --> NaCL + H2O
we know that we have 1M of each.
after using up 15mL of NaOH to neutralize the 5 mL HCl, I know that I have: 1M * 0.015L = 0.015mol * 40g/mol = 0.6mol.
moles of NaOH = 0.6mol = moles of HCl
so will the moles of water be 1-0.6 = 0.4? From there I do * 18g/mol = 7.2 g
Thanks a lot for your continuous help Dr.Bob! It's really appreciated!
4 answers
If I remember you had a density of HCl solution and the mass of that solution was mass = volume x density = 5 mL x density in g/mL = ? g. You can estimate the mass H2O by (mass soln - mass HCl) in the soln.
The problem is that I don't have the solutions total mass.
Would it actually be from the 0.015 above * 40g/mol = 0.6g. - 0.5475g (HCl)?
mass HCl in the 5.00 mL. That = mols HCl (which you obtained from M x L) x molar mass HCl = grams HCl. Then mass H2O = 5.25 - grams HCl = mass H2O.