Acids and Bases and Chemical Reactions

What are some properties of acids? Taste sour (not in the lab though … ) Conduct electricity Turns litmus red All begin with H + pH less than 7

What is this litmus stuff? It is a paper coated with a lichen used to indicate acids or bases. If its an acid it will turn red If its a base it will turn blue

What are some real life acids? Carbonic and Phosphoric acid- soda Lactic acid- yogurt Citric Acid- orange juice

What are some properties of bases? Taste bitter Feel slippery Turn litmus paper blue Conduct electricity pH more than 7

What are some real life bases? Bleach Ammonia Soap Antacid

What is an important base to just know? Ammonia, NH 3

What is an indicator? Something that changes color to tell you if you have an acid or a base.

Hydrangeas…a natural indicator Change from pink to blue in different pH soils.

HLc

What is pH? It is the negative logarithm of the hydrogen ion concentration. Measures the concentration of hydrogen ions

What is the pH scale? A way of determining acids or bases numerically.

What is the range for a base? pH greater than 7 The farther away it gets from 7 the stronger the base So 14 is a strong base 7.1 is a weake base

What is the range for an acid? pH less than 7 Farther away it gets from 7 the stronger the acid so 0 is a strong acid 6.9 is a weak acid

What is the pH of a neutral solution? 7

What is pOH? The concentration of Hydroxide (OH) Find pOH The negative logarithm of the OH- concentration.

What do pH + pOH equal? pH + pOH =14

How do you solve for pH? -log [H+]= pH Or pH +pOH=14

Example: Find the pH for the following: M HCl -log(0.0125) = = pH Acid or Base? Its an acid pH is less than 7 The pOH is 7.7 pH + pOH = 14 pH = 14so pH = 6.3 Acid or Base?Its an acid pH is less than 7

More Examples The [H+] ion concentration is 3.4x10 -4 Acid or Base? - log (3.4 x ) = (this is the pH) Acid The pOH is Acid or Base? pH + pOH = 14 pH = 14so pH = 2.46 Acid

The hydrogen ion concentration is 2.5 x M. What is the pH? -log(2.5 x ) = 4.60 pH = 4.60

The pOH is 5.7. What is the pH? pH + pOH = = 8.3

Is the hydroxide ion concentration of 1 x M an acid, base, or neutral? -log (1 x ) = 4 This is the pOH Must find pH to determine if acid, base, neutral pH + pOH = = 10pH = 10 So it’s a base

-ide Acids (also called binary acids) Contains HYDROGEN and an anion that ends in –ide (from the periodic table) Hydro no O HF H 2 S

Naming Rules Write HYDRO Add the ROOT OF THE NAME of the element. Add -IC to the end. Write the word ACID.

What are the weird ones? C, P, and S Hydrocarbonic Acid Hydrophosphoric Acid Hydrosulfuric Acid

Your Turn HF Hydrofluoric acid Hydronitric acid H 3 N

Polyatomic Acids Contains Hydrogen and a Polyatomic Ion. H 2 CO 3 HC 2 H 3 O 2

Naming Rules Identify the POLYATOMIC ion present. Change – ate to – IC. Change – ite to – OUS. Write the word ACID.

Use your chart on the back of your periodic table!!

What are the weird ones? P and S Sulfuric AcidH 2 SO 4 Sulfurous AcidH 2 SO 3 Phosphoric AcidH 3 PO 4 Phosphorous AcidH 3 PO 3

Examples HC 2 H 3 O 2 (C 2 H 3 O 2 - ) acetate  ic acetic acid Chloric Acidic  ate Chlorate (ClO 3 - )pair it with H + Swap n drop HClO 3 HClO2(ClO2 - ) Chlorite  ous Chlorous acid

A way to remember them maybe? I ate the acid. It was ic. Don’t bite ous. Neither of these has hydro.

How are bases named? Just like we have always named compounds. Swap n Drop!! Bases usually have OH - Hydroxide CO 3 -2 Carbonate HCO 3 - Bicarbonate

Examples Sodium Hydroxide Na + OH - NaOH Ammonium Hydroxide NH 4 + OH - NH 4 OH Mg(OH)2 Mg +2 OH - Magnesium Hydroxide

What happens when you put an acid and a base together? They neutralize

What does neutralize mean? It is no longer acidic or basic. Your pH is 7

What do they make? An acid and base make a salt and water. They are now neutral

What is a salt? An ionic compound that was the result of an acid/base neutralization reaction.

What is a hydrogen ion? H + Just a proton

It is only a proton because Hydrogen has 1 proton and 1 electron. The + charge means you lost an electron. All that is left is a proton in the nucleus.

What is hydroxide? OH -

What do they do? Help to determine if something is acidic or basic.

What is a neutral solution? One that has equal amounts of H + and OH -

How did Arrhenius define an acid? Something that contains H + (will be written first)

How did he define a base? Something that contains OH - Written second, its an anion.

How would Arrhenius define the following? HCl NaOH Ca(OH) 2 H 2 SO 4 HClO 3 NH 3

Oops … What happened? Arrhenius is wrong. Ammonia is a strong base, but according to his theory, it would be neither.

What is the next acid/base guy? Bronsted-Lowry acids and bases

What did they say? They tried to fix the definition of acids and bases. In a solution, the H + travels to either accept or donate.

What is a B-L acid? Something that donates H + ions

What is a B-L base? A B-L base is a H + acceptor.

How does this make NH 3 a base? It can accept H + so it is now a base. NH 3 is a BASE in water. NH 3 accepts H + to make NH 4 Water is itself an ACID. Water donates H + to make OH -

What is a conjugate acid? It is what is produced when a base accepts H +. Conjugates are PRODUCTS!!

What is a conjugate base? It is what is produced when an acid donates H + Conjugates are PRODUCTS!!

What? Bases make conjugate acids Acids make conjugate bases ****Each pair is made up of the same elements Only difference is a H+

Conjugate Pairs They differ in a HYDROGEN ion

Examples H 2 O + NH 4 +  NH 3 + H 3 O + HCOOH + CN -  HCOO - + HCN NH CO 3 -2  HCO NH 3 H 2 PO OH -  HPO H 2 O

What is a polyprotic acid? An acid that contains more than one H

What kinds are there? Monoprotic 1 H Diprotic 2 H Triprotic 3 H

What is an example? H 2 S H 3 PO 4 H 2 SO 4

What is special about water?? It can act as either an acid or base

What is that called? Amphoteric