Page 126 - Microsoft Word - LessonPlan-Overview.doc
P. 126
are also part of the game. (protons). This is a type of double
Oxidation numbers are used to displacement reaction that occurs,
help keep track of everything, and oddly enough, between an acid and
you’ll find information on how to do a base. The reaction between
this in your high school level hydrobromic acid (HBr) and sodium
textbook download. hydroxide (NaOH) is an example of
an acid-base reaction:
Decomposition: This type of
HBr + NaOH --> NaBr + H 2O
reaction breaks a complicated
molecule into simpler ones (AB Neutralization Reaction
A + B). When you leave a bottle of (Hydrolysis) When acids and
hydrogen peroxide on the counter, bases react with each other, they
it decomposes into water (H 2O) sometimes form a salt and water.
and oxygen (O 2).
Now I want to be clear about this:
2H 2O O 2 + 2H 2 ‘Salt’ doesn’t mean table salt
(NaCl), but rather an ionic
Displacement: There are several
compound formed from acid-base
different types of displacement
combinations. Salts are held
reactions, including single, double,
together by electrical charges
and acid-base.
(that’s what makes it an ionic
An example of a single
bond), as they are formed between
substitution reaction (A + BC +
cations (positive ions, like Na ) and
AC + B) occurs when zinc anions (negative ions, like Cl ).
-
combines with hydrochloric acid.
The salt can either stay in the
The zinc replaces the hydrogen:
solution as ions, or ‘fall out’ of the
Zn + 2 HCl ZnCl 2 + H 2
solution like a snow globe (called
A double displacement
precipitate). When the acids and
(metathesis) reaction has two
bases combine to form salt and
compounds exchanging bonds to
water, it’s called a neutralization
form new compounds (AB + CD --
reaction.
> AD + CB). Antacids like calcium
Salts can be any color of the
hydroxide (CaOH) combine with
rainbow, from the deep orange of
stomach acid (HCl) to form calcium
potassium dichromate to the vivid
chloride salt (CaCl 2) and water
purple of potassium permanganate
(H 2O).
to the inky black of manganese
CaOH + HCl CaCl 2 + H 2O
dioxide. Did you know that MSG
An acid-base reaction deals with (monosodium glutamate) is a salt?
reactions that involve hydrogen Most salts are not consumable, as
© 2010 Supercharged Science www.ScienceLearningSpace.com
528
