Characteristics of Acids and Bases

(Short form lab write-up)

Purpose: To discover some of the essential properties of acids and bases and their reactions, and to characterize an Unknown.

 

Hypothesis: The Unknown selected is a strong/weak: acid/base

 

Data:

Acid or Base

BTB

Litmus

Phen

UI

Washing

Soda

Baking

Soda

Tums

Marble

CuSO4

NaOH (strong base)

 

 

 

 

 

 

 

 

 

NH3 (weak base)

 

 

 

 

 

 

 

 

 

CH3COOH

(weak acid)

 

 

 

 

 

 

 

 

 

HCl (strong acid)

 

 

 

 

 

 

 

 

 

Unknown #_____

 

 

 

 

 

 

 

 

 

 

Procedure:

1.      Use plastic soda straws to place a SMALL amount of each material to be tested on the plastic sheet.

 

2.      React 2-3 drops of each acid or base with each listed indicator or household substance on a plastic reaction surface.

 

3.      Record your observations.

 

Make sure no paper or marble chips get into the sink!

 

Analysis Questions:

  1. Which compounds are the acids?  How can you tell?  Which are bases?
  2. What do the acids and bases all have in common?
  3. How are the acids different from the bases?
  4. Did you notice any differences between the strong acid (HCl) and the weak acid (CH3COOH)?  What were they?
  5. Did you notice any differences between the strong base (NaOH) and the weak base (NH3)?  What were they?
  6. Which Unknown did you use?  Characterize the unknown solution sample.  Is it

a.       Acid or base.

b.      Strong or weak.

7.  The baking soda, washing soda, Tums and marble all react with acids in much the same way.  What do these materials all have in common chemically?  What is the net reaction for these materials reacting with acid?