Acids, Bases, & Salts (1)
-
Upload
sandip-ajmire -
Category
Documents
-
view
266 -
download
1
Transcript of Acids, Bases, & Salts (1)
-
7/27/2019 Acids, Bases, & Salts (1)
1/30
Acids, Bases, & Salts
-
7/27/2019 Acids, Bases, & Salts (1)
2/30
What is an ACID?pH less than 7
Neutralizes bases
Forms H + ions in solution
Corrosive-reacts with most
metals to form hydrogen gas Good conductors of electricity
-
7/27/2019 Acids, Bases, & Salts (1)
3/30
Acids Generate Ions
HNO3 + H2O H3O+ + NO3
-
7/27/2019 Acids, Bases, & Salts (1)
4/30
Weak vs. Strong Acids
Weak Acids do not ionize completely:
Acetic, Boric, Nitrous, Phosphoric,
Sulfurous
Strong Acids ionize completely:
Hydrochloric, Nitric; Sulfuric, Hydriodic
-
7/27/2019 Acids, Bases, & Salts (1)
5/30
Common Acids
HCl- hydrochloric- stomach acid
H2SO4- sulfuric acid - car batteries
HNO3
nitric acid - explosives
HC2H3O2- acetic acid - vinegar
H2CO3-carbonic acidsodas
H3PO4- phosphoric acid -flavorings
http://agitator.dynip.com/agitator/Generator/interstate.jpghttp://www.funset.com/images/pepsi.gifhttp://users.erols.com/interlac/homehy/vinegar.jpg -
7/27/2019 Acids, Bases, & Salts (1)
6/30
http://www.thebird.org/store/clean/internal/acidsam.gif -
7/27/2019 Acids, Bases, & Salts (1)
7/30
What is a BASE?
pH greater than 7
Feels slippery
Dissolves fats and oils
Usually forms OH-ions in
solutionNeutralizes acids
-
7/27/2019 Acids, Bases, & Salts (1)
8/30
Weak vs. Strong Bases
Weak Bases: ammonia; potassium
carbonate, sodium carbonate
Strong Bases: sodium hydroxide; sodium
phosphate; barium hydroxide; calcium
hydroxide
-
7/27/2019 Acids, Bases, & Salts (1)
9/30
Common Bases
NaOH- sodium hydroxide (LYE) soaps, drain cleaner
Mg (OH)2 - magnesium hydroxide-antacids
Al(OH)3-aluminum hydroxide-antacids, deodorants
NH4OH-ammonium hydroxide- ammonia
http://images.google.com/imgres?imgurl=www.speedstick.com/images/deodorants/products.jpg&imgrefurl=http://www.speedstick.com/deodorants.html&h=279&w=325&prev=/images%3Fq%3Ddeodorants%26svnum%3D10%26hl%3Den%26lr%3D%26ie%3DUTF-8%26oe%3DUTF-8http://www.epa.gov/grtlakes/seahome/housewaste/images/hhwp18.gifhttp://www.cnn.com/HEALTH/9708/15/nfm.heartburn.hiding/antacids.jpghttp://images.google.com/imgres?imgurl=www.redbushtea.com/soap/images/soap.jpg&imgrefurl=http://www.redbushtea.com/soap/soap.html&h=203&w=257&prev=/images%3Fq%3Dsoap%26svnum%3D10%26hl%3Den%26lr%3D%26ie%3DUTF-8%26oe%3DUTF-8%26sa%3DG -
7/27/2019 Acids, Bases, & Salts (1)
10/30
Types of Acids and Bases
In the 1800s chemical concepts were based on the
reactions of aqueous solutions.
Svante Arrhenius developed a concept of acidsand bases relevant to reactions in H2O.
Arrhenius acidproduces hydrogen ions in water. Arrhenius baseproduce hydroxide ions in water.
-
7/27/2019 Acids, Bases, & Salts (1)
11/30
A broader ,more modern concept of acids and
bases was developed later.
Bronsted-Lowry acid- donates a hydrogen ion
in a reaction.
BronstedLowry baseaccepts a hydrogen
in a reaction.
-
7/27/2019 Acids, Bases, & Salts (1)
12/30
Conjugate acid- compound formed when an
base gains a hydrogen ion.
Conjugate basecompound formed when
an acid loses a hydrogen ion.
-
7/27/2019 Acids, Bases, & Salts (1)
13/30
pH Scale
http://bcn.boulder.co.us/basin/data/COBWQ/info/pH.gif -
7/27/2019 Acids, Bases, & Salts (1)
14/30
pH of Common Substances
Timberlake, Chemistry 7th Edition, page 335
http://d/chemistry%20file/Acids,%20Bases,%20&%20Salts.ppt -
7/27/2019 Acids, Bases, & Salts (1)
15/30
Reactions with indicators
Indicator Acid
color
Neutral
color
Base
color
Phenolphthalein Colorless Faint pink Dark pink
Bromthymol
blue
Yellow Green Blue
Litmus Red ----- Blue
-
7/27/2019 Acids, Bases, & Salts (1)
16/30
pH paper
pH paper changes
color to indicate a
specific pH value.
http://images.google.com/imgres?imgurl=http://www.chem.ucla.edu/~gchemlab/ph-paper.jpg&imgrefurl=http://www.chem.ucla.edu/~gchemlab/lab_hardware_web.htm&h=315&w=375&sz=11&hl=en&start=2&tbnid=M6BvJEJBykPVhM:&tbnh=102&tbnw=122&prev=/images%3Fq%3DpH%2Bpaper%26gbv%3D2%26hl%3Den%26safe%3Dactive%26sa%3DG -
7/27/2019 Acids, Bases, & Salts (1)
17/30
Buffers
A buffer is a solution that resists changes in
pH when small amounts of acids and bases
are added.
-
7/27/2019 Acids, Bases, & Salts (1)
18/30
Situations in which pH is controlled
Heartburn
Planting vegetables and flowers
Fish Tanks and Ponds
Blood
Swimming pools
-
7/27/2019 Acids, Bases, & Salts (1)
19/30
Acids and Bases in Solution
HCl + H20 H3O + + Cl-(more hydronium ions, more acidic)
NaOH in water Na+ + OH-
(more hydroxide ions, more basic) NaOH + HCl NaCl + HOH
Acid + Base yields type of salt and water
NH3 + H20 NH4+ + OH-ammonia gas + water yields ammonium and
hydroxide ions
-
7/27/2019 Acids, Bases, & Salts (1)
20/30
Acid Rain
Pollution in the air (sulfur dioxide, carbon
dioxide, nitrogen dioxide) combines with
water to form various acids..
-
7/27/2019 Acids, Bases, & Salts (1)
21/30
Rapid changes in pH can kill fish
and other organisms in lakes and
streams.
Soil pH is affected and can kill
plants and create sinkholes
-
7/27/2019 Acids, Bases, & Salts (1)
22/30
http://www.plugged-in.org/images/parthenon2.jpghttp://llv2.terc.edu/acidrain/content_students/session02/session02_01/images/s02_page02a_pic.jpg -
7/27/2019 Acids, Bases, & Salts (1)
23/30
-
7/27/2019 Acids, Bases, & Salts (1)
24/30
-
7/27/2019 Acids, Bases, & Salts (1)
25/30
What is a SALT? A salt is a neutral substance produced from the
reaction of an acid and a base.
Composed of the negative ion of an acid and the
positive ion of a base. One of the products of a Neutralization Reaction
Examples: KCl, MgSO4, Na3PO4
http://www.genhealth.com/salt.jpghttp://www.bonaire-travelguide.com/sights/photos/salt-index.jpghttp://www.vermontsoap.com/images/bathsalts.jpg -
7/27/2019 Acids, Bases, & Salts (1)
26/30
Neutralization Reaction
A neutralization reaction is the reaction of
an acid with a base to produce salt and
water. Example
H2SO4 + NaOH NaHSO4 + H2O
-
7/27/2019 Acids, Bases, & Salts (1)
27/30
Digestion and pH
Digestion-process by which foods are broken down
into simpler substances.
Mechanical digestion-physical process in which food
is torn apart (mouth)
Chemical digestion- chemical reactions in which large
molecules are broken down into smaller molecules.
(stomach and small intestines)
http://images.google.com/imgres?imgurl=whyfiles.org/124space_station/images/astronaut_eating.jpg&imgrefurl=http://whyfiles.org/124space_station/4.html&h=200&w=151&prev=/images%3Fq%3Dmouth%2Beating%26svnum%3D10%26hl%3Den%26lr%3D%26ie%3DUTF-8%26oe%3DUTF-8http://images.google.com/imgres?imgurl=www.mathersweb.com/grandkids/Eating.jpg&imgrefurl=http://www.mathersweb.com/grandkids/lexi15months.html&h=237&w=243&prev=/images%3Fq%3Dmouth%2Beating%26svnum%3D10%26hl%3Den%26lr%3D%26ie%3DUTF-8%26oe%3DUTF-8http://images.google.com/imgres?imgurl=whyfiles.org/124space_station/images/astronaut_eating.jpg&imgrefurl=http://whyfiles.org/124space_station/4.html&h=200&w=151&prev=/images%3Fq%3Dmouth%2Beating%26svnum%3D10%26hl%3Den%26lr%3D%26ie%3DUTF-8%26oe%3DUTF-8 -
7/27/2019 Acids, Bases, & Salts (1)
28/30
pH in the Digestive System
Mouth-pH around 7. Saliva contains amylase, an
enzyme which begins to break carbohydrates into
sugars. Stomach- pH around 2. Proteins are broken down
into amino acids by the enzyme pepsin.
Small intestine-pH around 8. Most digestion ends.
Small molecules move to bloodstream toward
cells that use them
-
7/27/2019 Acids, Bases, & Salts (1)
29/30
mouth
esophagus
stomach
small intestine
large intestine
Digestive system
http://fairmanstudios.com/images/digestive_sys.jpg -
7/27/2019 Acids, Bases, & Salts (1)
30/30
Acids, Bases, and Salts
The End