Unit 5- Acids & Bases Flashcards Preview

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Flashcards in Unit 5- Acids & Bases Deck (13):
1

Arrthenius theory of acids and bases

1887
Covers the dissociation of acids and bases in water.
What happens when you put an acid or a base into water?
Acids produce hydrogen ions H+
Bases produce hydroxide ions OH-

2

Bronsted-Lowry Theory

1923
And acid-base reaction consists of the transfer of a proton from an acid to a base
-an acid is a substance from which a proton can be removed
-a base is a substance that can remove a proton from an acid

3

Conjugate pair

A pair of chemical species, which differ by only one proton

4

Conjugate acid

The chemical species with the extra proton

5

Conjugate base

The chemical species that lacks the extra proton

6

Polyprotic acids

are specific acids that are capable of losing more than a single proton per molecule in acid-base reactions. (In other words, acids that have more than one ionizable H + atom per molecule)

7

Strong acids/bases

Strength= the degree of ionization or dissociation of the acid or base in an aqeous solution
-strong acids are those that have a Ka greater than 1
-favours products
-shown with forward arrow only
-Strong acids are completely dissociated
-The Ka of these strong acids is very high
-Strong bases ionize completely into hydroxide ions and a conjugate acid

8

Weak acid/base

If the acid is less than 100% dissociated it is termed a weak acid. They are partially ionized or dissociated & therefor form few ions
Ka values for weak acids are small
SEE CHART to figure out if sting or weak. Acids go from strong to weak and bases weak to strong
Shown with double sided arrows

9

Amphiprotic/ amphoteric acids

Amphiprotic- a substance that can both donate or accept a proton
- all amphiprotic substances contain a hydrogen atom
-it acts either as an acid or a base
Amphoteric-a substance that acts like an acid or base
-they are amphiprotic
Ex: H2O becomes H3O+ or OH-
HSO4- becomes H2SO4 or (SO4)2-

10

Indicators

A pH indicator is a halochromic chemical compound added in small amounts to a solution so the pH of the solution can be determined visually.

11

Neutralization

a chemical reaction in which an acid and a base react quantitatively with each other

12

Titration

the slow addition of one solution of a known concentration (called a titrant) to a known volume of another solution of unknown concentration until the reaction reaches neutralization, which is often indicated by a color change. The solution called the titrant must satisfy the necessary requirements to be a primary or secondary standard. In a broad sense, titration is a technique to determine the concentration of an unknown solution.

13

Equivalency/end point

An endpoint is indicated by some form of indicator at the end of a titration. An equivalence point is when the moles of a standard solution (titrant) equal the moles of a solution of unknown concentration