Acids and Bases
Everyday you encounter a variety of different acids and bases. Below is a list of some common acids and bases
Milk Soap
carbonic acid (H2CO3)
calcium hydroxide (Ca(OH)s)
sodium hydroxide (NaOH)
hydrochloric acid (HCl)
Definitions (Arrhenius)
1)
Acid – a substance that produces _____________ in solution
e.g. hydrochloric acid, HCl(aq) dissolves in water to produce H+(aq) and Cl­(aq) ions
2)
Base – a substance that produces ______________ in solution
e.g. sodium hydroxide, NaOH(aq) dissolves in water to produce Na+(aq) and OH­(aq) ions
Properties of an Acid
Acids have many different properties. Chemists use these to determine the presence of an acid in a substance. Reactions with Metal Acids react with metals to produce bubbles of gas. HA + metal The gas produced when you react an acid with a metal is _________________.
During an experiment you can test for the presence of this gas by using a ______________ splint, which causes a _______________.
Reaction with Carbonates
Acids also react with metal carbonates to produce a different form of gas.
HA + metal carbonate The gas produced when you react an acid with a carbonate is __________________. You can test for the presences of this gas by using a ________________ splint, which causes the ___________________.
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More Properties of Acids
Electrical Conductivity
Many acids are ___________ conductors of electricity. In order for a solution of conduct electricity it must contain ___________. When an acid is diluted in water, the water molecules collide with the acid molecules which causes the formation of _________ (H+) and ______________. This process is called ________________.
ex. ­
+
HCl(aq) H (aq) + Cl (aq)
­
+
H (aq) + A (aq)
HA
(aq)
Reactions with Indicators
In this class we will be using three different acid­base indicators to test for acids.
Phenolphthalein litmus paper
bromothymol blue
When you put the indicator in the acid, the acid will change colour.
turns red in turns colourless in turns yellow in
Touch and Taste
If you were to spill and acid on an open wound on your skin it would _____________. Stronger acids could burn your skin. Acids taste sour (ex. lemons, grapefruit, spoiled milk). (NOTE: Never taste an acid in a chemistry lab!!)
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Property of Bases
Reactions with Metal and Carbonates
Unlike acids, bases do not react with metals and carbonates to produce a gas.
Electricity Conductor
Bases are ___________ conductors of electricity. Since many common bases are ionic compounds, when they dissolve in water their _____________ are released. ex.
NaOH
+
­
(s) Na (aq) + OH (aq) Reactions with Indicators
When you put an acid­base indicator in a base it will change colour
turns blue in
turns pink in turns blue in
Touch and Taste
Bases feel _____________ on your skin. Bases taste bitter (soap, Brussels sprouts). pH Scale
Chemists use a numerical scale to determine how acidic or basic a solution is. The _________________ ranges from 0 to 14. A solution with a pH of 7 is ________________, which means that it is not acidic nor basic (the concentration of hydrogen ions equals the concentration of hydroxide ions). ___________ has a pH of 7. A solution with a pH less than 7 is considered _____________, which means that there are more _____________ ions than _____________ ions. A solution with a pH greater than 7 is considered _______________, which means that it has more ______________ ions than _______________ ions. A solution with a pH closer to 0 is a _____________________.
A solution with a pH just below 7 is a ____________________.
A solution with a pH just above 7 is a _____________________.
A solution with a pH closer to 14 is a _____________________.
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