Calculating pH with H+ or H3O+

Moderators: Chem_Mod, Chem_Admin

Ayesha Aslam-Mir 3C
Posts: 112
Joined: Wed Sep 30, 2020 9:43 pm

Calculating pH with H+ or H3O+

Postby Ayesha Aslam-Mir 3C » Sat Dec 05, 2020 3:05 pm

Is it possible for an acidic solution to have a different number of moles of H+ and H3O+? (like if there aren't enough H+ for H20?) Or is this not possible in acidic compounds in aqueous solution.

If so, which would you use to calculate the pH of the solution?

SavannahScriven_1F
Posts: 98
Joined: Wed Sep 30, 2020 9:37 pm

Re: Calculating pH with H+ or H3O+

Postby SavannahScriven_1F » Sat Dec 05, 2020 3:27 pm

I would assume the H+ concentrations and H3O+ concentrations are always equal. I think Lavelle said H+ and H3O+ mean the exact same thing, but some chemists prefer to write H3O+ because it is more descriptive of what is going on in the solution.

Chem_Mod
Posts: 19542
Joined: Thu Aug 04, 2011 1:53 pm
Has upvoted: 882 times

Re: Calculating pH with H+ or H3O+

Postby Chem_Mod » Sat Dec 05, 2020 3:27 pm

In this case, H+ and H3O+ are synonymous. Ideally, the correct notation is H3O+, which is used to calculate the pH using the negative log rule.

Andre Fabian 1F
Posts: 101
Joined: Wed Sep 30, 2020 10:03 pm
Been upvoted: 2 times

Re: Calculating pH with H+ or H3O+

Postby Andre Fabian 1F » Sat Dec 05, 2020 4:07 pm

In Dr. Lavelle's lectures he stated that H+ and H3O+ for the purposes in this class can be used interchangeably, but he mentioned that in later chemistry classes, in chemical equations we should write it out as HA + H20 = A +H30.

In addition, pH can be calculated as pH = -log10[H+]


Hope this helps!
Andre


Return to “Calculating pH or pOH for Strong & Weak Acids & Bases”

Who is online

Users browsing this forum: No registered users and 1 guest