Acids and BasesAcids and Bases

Unit 10 – Honor’sUnit 10 – Honor’s

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Acid Base Salt Water

pH below 7

Sour taste

Reacts withmetals andbases

electrolyte

pH above 7

Bitter taste

Reacts withfats andoils and acids

electrolyte

Electrolyte

pH near 7

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pH is a measure of the pH is a measure of the amount of hydronium amount of hydronium ion. ion. pH = -log[concentration HpH = -log[concentration H++]]

[10[10-1-1M HCl] ; pH = 1M HCl] ; pH = 1[10[10-2-2M HCl] ; pH = 2M HCl] ; pH = 2[10[10-3-3M HCl] ; pH = 3M HCl] ; pH = 3[10[10-4-4M HCl] ; pH = 4M HCl] ; pH = 4[10[10-5-5M HCl] ; pH = 5M HCl] ; pH = 5[10[10-6-6M HCl] ; pH = 6M HCl] ; pH = 6[10[10-7-7M HCl] ; pH = 7M HCl] ; pH = 7

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pOH is a measure of pOH is a measure of the amount of the amount of hydroxide ion. hydroxide ion. pOH = -log[concentration OHpOH = -log[concentration OH--]]

[10[10-1-1M NaOH] ; pOH = 1M NaOH] ; pOH = 1[10[10-2-2M NaOH] ; pOH = 2M NaOH] ; pOH = 2[10[10-3-3M NaOH] ; pOH = 3M NaOH] ; pOH = 3[10[10-4-4M NaOH] ; pOH = 4M NaOH] ; pOH = 4[10[10-5-5M NaOH] ; pOH = 5M NaOH] ; pOH = 5[10[10-6-6M NaOH] ; pOH = 6M NaOH] ; pOH = 6[10[10-7-7M NaOH] ; pOH = 7M NaOH] ; pOH = 7

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pH and pOHpH and pOH

These are log rhythmic scales!Each number is a power of 10

10-1 = 0.110-2 = 0.0110-3 = 0.00110-4 = 0.000110-5 = 0.0000110-6 = 0.000001

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pH is how much acid.pH is how much acid.What is pOH?What is pOH?

pOH is how muchbase, the more basethe lower the pOH

Since pH = -log[H+]less is more!The smaller the pH,the less negative is theexponent.Smaller pOH = smallerNegative exponent!

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Naming Acids.Naming Acids.Binary Acids:

ex: HCl, HBr, HSe Hydro _________ ic acid

Oxyacidsex: H2SO4, H3PO4, HNO3

______________ ic acid

Or

ex: H2SO3, H3PO3, HNO2

______________ ous acid

chlorbromselen

sulfurphosphornitr

sulfurphosphornitr

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How can you tell if you How can you tell if you have an acid?have an acid?

The first symbol The first symbol in the formula in the formula are H … are H … Hydronium ion is Hydronium ion is in acids.in acids.

ClH

S O HOH

O

O

HCl =Hydrochloric acid

H2SO4 =sulfuric acid

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How can you tell if you How can you tell if you have a base?have a base?

The last two The last two symbols in the symbols in the formula are OH formula are OH … Hydroxides are … Hydroxides are bases.bases.

Na O H

Ca O HOHNaOH = sodium hydroxide Ca(OH)2 = calciumhydroxide

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What is Kw?What is Kw?

Kw is an Kw is an equilibrium equilibrium expression for the expression for the dissociation of dissociation of water.water.

[H[H33OO++][OH][OH--] = 10] = 10-14-14

[ H[ H33OO+ + ][ OH][ OH- - ] = 10] = 10-14-14

In a solution of 0.01M HCl, all the HCl In a solution of 0.01M HCl, all the HCl dissociates, [Hdissociates, [H++] = 0.01M. What is the ] = 0.01M. What is the concentration of OHconcentration of OH--??

0.01M 1010-14-14

0.01M[OH-] = 10-12 M