1 / 5

Bases

Acids. and. Bases. Properties of acids and bases. Get 8 test tubes. Rinse all tubes well with water. Add acid to four tubes, base to the other four. Touch a drop of base to your finger. Record the feel in the chart (on the next slide). Wash your hands with water. Repeat for acid.

filbert
Download Presentation

Bases

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Acids and Bases

  2. Properties of acids and bases • Get 8 test tubes. Rinse all tubes well with water. Add acid to four tubes, base to the other four. • Touch a drop of base to your finger. Record the feel in the chart (on the next slide). Wash your hands with water. Repeat for acid. • Use a stirring rod, add base to the litmus and pH papers (for pH paper use a colour key to find a number). Record results. Repeat for acid. • Into the four base tubes add: a) two drops of phenolphthalein, b) 2 drops of bromothymol, c) a piece of Mg, d) a small scoop of baking soda. Record results. Repeat for acid. • Cleanup(wash tubes,pH/litmus paper in trash).

  3. Observations *Usually, but not always NaOH(aq) HCl(aq) Taste Feel (choose slippery or not slippery) pH (# from the key) Litmus (blue or red) Phenolphthalein Bromothymol Magnesium Baking soda

  4. pH • There are many ways to consider acids and bases. One of these is pH. • [H+] is critical in many chemical reactions. • A quick method of denoting [H+] is via pH. • The pH scale, similar to the Richter scale, describes a wide range of values • An earthquake of “6” is 10 as violent as a “5” • Thus, the pH scale condenses possible values of [H+] to a 14 point scale • Also, it is easier to say pH=7 vs. [H+]=1x10–7

  5. + + + H H O H O Cl Cl H H H • In this idea, the ionization of an acid by water is just one example of an acid-base reaction. The Bronsted-Lowry concept conjugate acid conjugate base acid base conjugate acid-base pairs • Acids and bases are identified based on whether they donate or accept H+.

More Related