ACIDS AND BASES LAB    I.M.S. SCIENCE    Name: __________________________

                                                                                 Period: ______ Date:`___________

Compounds dissolved in water are called solutions.  Solutions have characteristics that we are going to investigate.  Solutions are neutral, an acid or a base.  In this exercise we are going to test some solutions to see if they are neutral, acid or base. Ions are atoms with electron imbalances. Electrolytes are solutions which conduct electric current. Crystals are made up of orderly assemblage of positive and negative ions.

Acids- positive ion is hydrogen (H+) hydronium                  Bases- negative ion is hydroxide (OH-)

Citric, acetic, lactic-RAS                                                                      alkai, caustic-BBB

Materials: Tray, plastic well tray, ph indicator paper, ph meter,cabbage water, medicine, toothpicks, household solutions, and this handout. * Internet site(s)

            SOUR                                                     BITTER

              Acid                        neutral                       Base

0    1     2     3     4     5     6      7       8    9    10    11    12    13     14

Blue Litmus turns red in an acid.                  Red litmus turns blue( green) in a base.

Cabbage water turns red in an acid. Cabbage water turns blue( green)  in an base.

The litmus (Cabbage water) will not change if the solution is neutral.

* Litmus is a plant dye that changes color in the presence of acids or bases.

Salts form when either acids or bases are neutralized.

Procedure:

1.      On the plastic tray place a drop of the solutions into the numbered wells.

2.      Test the solutions with ph indicator paper.  Record your results on your data table.

3.      Test your solutions with cabbage water by putting a drop or two of cabbage water into each of the solutions and mix. Record your results on the data table.

4.      Compare your results with that of another lab group. * Internet site(s) Explore Ph panel

5.      Retest any solutions you did not agree on with a large difference.    

Acids, Bases and Salts

Electrolytes- solutions which conduct electric current

Ions- are atoms or groups of atoms that have lost or gained electrons.

Na + Cl - ======= Na+Cl- { an ionic compound}

Crystals- are made up of an orderly assemblage of positive and negative ions.

ionized- substances  break up in water solution to form ions.

            ( non-electroytes- do not ionize )

Acid, bases and salts are electrolytes.

Acids- Sour- red ( litmus )

Bases- bitter-blue ( litmus )

( litmus )- IS A PLANT DYE THAT HAS THE PROPERTY OF CHANGING COLOR WHEN IT COMES IN CONTACT WITH ACIDS ( INDICATOR )

Salts- salt & water forms when either acids or bases are neutralized.

Neutralization:   HCL + NaOH ====  NaCl  + HOH

ACIDS:      R-A-S

- TURNS ( litmus BLUE) - RED

- CITRIC, ACETIC, AND LACTIC ( SOUR)

- H2O       +     HCL ====    H2O         *     H +  +     CL-

                                          HYDRONIUM ION ( ACID)

ADD ACID TO WATER!!!!!!!!!

BASE:       B-B-B

-     OH - HYDROXIDE

- NaOH             ====       NA+         +     OH -

- 2NaCL           +  H2O  ====      2NaOH       +     H2   + CL2

- ALKAI- STRONG BASE

- BITTER- CAUSTIC

- TURNS ( litmus RED ) - BLUE