How to tell acids and bases

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Priscilla Okaiteye
Posts: 61
Joined: Tue Nov 21, 2017 3:02 am

How to tell acids and bases

Postby Priscilla Okaiteye » Mon Jan 21, 2019 10:43 pm

Does anyone know a quick way to tell if a chemical is an acid or base without being given the formula?

emily gao 1C
Posts: 61
Joined: Fri Sep 28, 2018 12:29 am

Re: How to tell acids and bases

Postby emily gao 1C » Mon Jan 21, 2019 10:56 pm

I'm pretty sure they'll always give you the formula? or like acids are called acids: eg acetic acid, hydrochloric acid; bases are hydroxides eg: barium hydroxide

Christina Chang 1C
Posts: 34
Joined: Thu May 10, 2018 3:00 am

Re: How to tell acids and bases

Postby Christina Chang 1C » Mon Jan 21, 2019 10:57 pm

Generally, if there is an H it's an acid and if there is an OH then it's a base. I'm not quite sure if that's what you were trying to ask?

IsabelLight2H
Posts: 34
Joined: Wed Oct 03, 2018 12:15 am

Re: How to tell acids and bases

Postby IsabelLight2H » Mon Jan 21, 2019 11:33 pm

Typically, you just look at how it would react with water. Lot's of times if it has a negative charge, it's a base and a positive charge will be an acid.

Hannah Pham 1D
Posts: 62
Joined: Fri Sep 28, 2018 12:19 am

Re: How to tell acids and bases

Postby Hannah Pham 1D » Wed Jan 23, 2019 3:40 pm

In chem14a, we drew lewis dot structures, and through that, we saw if something was an acid or a base.

Felicia1E
Posts: 31
Joined: Fri Sep 28, 2018 12:22 am

Re: How to tell acids and bases

Postby Felicia1E » Wed Jan 23, 2019 4:14 pm

It also depends on which definition of acids and bases you are using. In this class I believe we mainly just use the Brønsted-Lowry definition of acids and bases, which follows:

A Brønsted-Lowry acid is anything that is a proton donor (when I say proton donor in this context it means an H+ ion, not to be confused with an actual proton).

A Brønsted-Lowry base is anything that accepts a proton (again, proton is used in the same sense).

There are also Arrhenius acids and bases, which are more specific than the Brønsted Lowry definition, and Lewis acids and bases, which encompasses a broader range of substances than both the Brønsted-Lowry and Arrhenius definitions.

Philipp_V_Dis1K
Posts: 32
Joined: Fri Sep 28, 2018 12:20 am

Re: How to tell acids and bases

Postby Philipp_V_Dis1K » Wed Jan 23, 2019 6:36 pm

Usually acids have an extra H on either the end or beginning of the chemical formula, and bases have an OH group.

Beatrice Petelo 1F
Posts: 62
Joined: Fri Sep 28, 2018 12:17 am

Re: How to tell acids and bases

Postby Beatrice Petelo 1F » Wed Jan 23, 2019 9:36 pm

Acids tend to have an H and bases OH

Also, the Bronsted-Lowry definition:
acid: proton (H+ ion) donor
base: proton acceptor

805087225
Posts: 30
Joined: Thu Jun 07, 2018 3:00 am

Re: How to tell acids and bases

Postby 805087225 » Thu Jan 24, 2019 9:50 am

Usually, the list of acids and bases remain a constant and we always know what they give us.
But if not, we have to figure out from the lewis structures after we draw them, or from the very formula, if it is given.


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