WHAT ARE THE PHYSICAL AND CHEMICAL BEHAVIOR OF ACIDS AND BASES? ACIDS: - Corrosive to metals( zinc,...

Post on 17-Jan-2016

212 views 0 download

Transcript of WHAT ARE THE PHYSICAL AND CHEMICAL BEHAVIOR OF ACIDS AND BASES? ACIDS: - Corrosive to metals( zinc,...

WHAT ARE THE PHYSICAL AND CHEMICAL BEHAVIOR OF ACIDS AND BASES?

ACIDS:- Corrosive to metals( zinc, aluminum, etc.)-When added to water it produces hydrogen ions (H+)-Turns litmus paper red-Tastes sour (lemons contain citric acid, for example)- produces CO2 gas when mixed with carbonate solns.- conducts electricity due to presence of ions.

Bases:- Feels soapy or slippery- Turns litmus paper blue- Tastes bitter (like soap) - Reacts with most cations to precipitate hydroxides- conducts electricity due to presence of ions.

HOW DO WE DIFFERENTIATE AN ACID FROM A BASE?

We differentiate an acid from a base by identifying which

substance possesses which property. If a substance tastes

sour, turns litmus paper to red, and ionizes when dissolved

in water it is an acid. If it tastes bitter, turns litmus paper to

blue, and gibes OH- when dissolved in water, it must be a

base. A substance with a pH of 7 is neutral.

HOW ARE THE STRENGTH OF ACIDS AND BASES BE IDENTIFIED?

A Strong base has a pH level nearer to 12 while a Weak base has a pH level nearer to 7.

Strong bases = LiOH, NaOH, CsOHWeak bases = ammonia

- There are two types of acids, the strong acids and the weak acids.

- If an acid is strong, its pH level is closer to 1, it is

completely ionized in water, and has a weak conjugate

base. A weak acid is closer to 7 and partially ionizes in

water to some extent lesser than 100%, and has a

stronger conjugate base.

Strong = HClO4, HCl, and HNO3

Weak = acetic acid, HF, and NH4+

HOW ARE ACIDS AND BASES QUANTIFIED(MEASURED)?

Acids are measured by using a pH (hydrogen potency)

indicator, such as Litmus paper. If a substance is within the

range 0-6, it is considered an acid. How closer it is to zero,

measure how weak it is and vice versa. A substance within

the range of 8-12, is considered basic, and the strenght

depends on how closer it to 7.

WHAT ARE PH INDICATORS?pH indicators are natural or synthetic

substances that change color in response to the nature of its chemical environment. They are used to provide information about the degree of acidity of a substance (pH). An example would be Litmus paper, a vegetable dye from Lichens that turns red in acidic solutions and blue in basic solutions.

WHAT ARE COMMON APPLICATIONS/USES OF ACIDS AND BASES? Acids

Vinegar – a household acid mostcommonly used for meal preparations and is also a cleaning agent. Also used in making homemade mayonnaise. Try now!

Citric Acid – used as a food additive, preservative, and aslo as a cleaning agent. Also used in making homemade mayonnaise. Try now!

Bases

Soap – (KOH) alkaline in nature and a very effective cleaning agent and mild antiseptic.

Baking Soda – primarily used for baking, and an effective cleaning agent.

CREDITS TO THE FOLLOWING SITES

http://www.visionlearning.com/library/module_viewer.php?mid=58

http://www.chemtutor.com/acid.htm

http://www.chem4kids.com/files/react_acidbase.html http://www.scienceclarified.com/everyday/Real-Life-Chemistry-Vol-2/Acid-Base-Reactions.html

http://chemistry.about.com/library/weekly/aa112201a.htm

http://101science.com/PH.html

http://www.erowid.org/archive/rhodium/chemistry/equipment/ph-indicator.html

http://www.hach.com/fmmimghach?/CODE:LG0045861|1//true

http://chemistry.about.com/gi/dynamic/offsite.htm?zi=1/XJ/Ya&sdn=chemistry&cdn=education&tm=198&gps=80_2885_1020_615&f=00&tt=14&bt=1&bts=1&zu=http%3A//www.chem.vt.edu/RVGS/ACT/notes/Notes_on_acids_and_bases.html

THANKS FOR LISTENING!

Good Luck to all! xD

pH means Hydrogen Potential ;)