U4 L21: Neutralization Reactions
6/1
• DQ: What happens when acids and bases are
mixed?
•ChemCat: Excess stomach acid, HCl, can cause extreme discomfort
and pain. Milk of magnesia, Mg(OH)2, is often taken to reduce stomach
acid.
a. What products do you think are produced when Mg(OH)2 and HCl
are mixed?
b. What products do you think are produced when HNO3 and HCl are
mixed?
You will be able to:
•
•
write a chemical equation for an acid-base neutralization
reaction
describe how the pH changes when acids and bases are
mixed
Short Lab Procedure
1) Add 10 drops of HCl solution to a watchglass.
2) Add 2 drops of universal indicator solution.
3) Slowly add NaOH solution drop by drop. Record all color changes
observed and how many drops it took to get there until the
solution is blue.
4) Now add HCl drop by drop until the solution is pink.
5) Add some baking soda to the watchglass and observe.
6) Wash off the watchglass in the sink.
What happens during a neutralization reaction?
Discussion Notes
•A neutralization reaction between an acid and a strong base in
aqueous solution produces an ionic compound (salt) and water.
•A neutralization reaction can be described as a double exchange
reaction in which the two compounds exchange cations.
Wrap Up
•What happens when acids and bases are mixed?
– A neutralization reaction between a strong acid and a
strong base produces an ionic salt and water.
– When strong acids and bases are mixed, the pH of the
product approaches 7 at 25 °C.