Acids And Bases

Question 1

Ph table

Answer 1

Acids
<7 and 1 is most acidic
H+&raquo_space; OH-
Red litmus paper stays red and turns blue litmus paper red

Neutral
=7
H+=OH-
Red litmus paper stays red and blue litmus paper stays blue

Basic
>7 and 14 is the most basic
H+«OH-
Red litmus paper turns blue and blue litmus stays blue

Question 2

Conjugate acids and bases

Answer 2

Definition
The Bronsted-Lowry definition of acids and bases
To show that a compound is acidic or basic, we write its reaction with water
An Acid donates protons to water to form hydronium ions (H3O+)
A Base accepts protons from water to form hydroxide ions (OH-)
NH3 + H2O ↔ OH- + NH4+
Base = Proton Acceptor
HCl + H2O ↔ H3O+ + Cl-
Acid = Proton donor
Conjugate Acid Base pairs
For every acid there is a conjugate base. For example: if H2O is the acid then OH- is the conjugate base
Similarly for every base there is a conjugate acid. If OH- is the base and H2O is the conjugate acid.
NH3 + H2O ↔ OH- + NH4+
HCl + H2O ↔ H3O+ + Cl-

Question 3

Amphiprotic substances

Answer 3

Amphiprotic Substances
→ some substances can both accept and donate protons depending on what they are reacting with, they are called amphiprotic substances.
HCO3- + H2O ↔ H3O+ + CO3-2
HCO3- + H2O ↔ OH- + H2CO3
water is another important amphiprotic substance.

Question 4

Strong acids

Answer 4

STRONG ACIDS

→ are fully dissociated

have a high K value (Ka) - so lots of products, H3O+

Equilibrium lies to the right - so lots of products

Strong acids have:

→ good conductivity

(as high [ions])

→ Low PH

(as high [H3O+])

→ Fast reaction rate

(as high [H3O+])

Examples of Strong acids

→ HCl

→ H2SO4

→ HNO3

Question 5

Weak acids

Answer 5

Weak acids

→ are partially dissociated

have a low K value (Ka) - so [low] of products, H3O+

Equilibrium lies to the left - so lots of reactants

Weak acids have:

→ Poor conductivity

(as low [ions])

→ Higher PH (still?)

(as lower [H3O+])

→ Slow reaction rate

(as low [H3O+])

Examples of weak acids

→ CH3COOH

→ HCOOH

→ HF

Question 6

Strong bases

Answer 6

Strong Bases

→ are ionic and therefore fully dissociated

have a high K value (Kb) - so lots of products, OH-

Equilibrium lies to the right - so lots of products

Strong bases have:

→ Good Conductivity

(as high [ions])

→ high pH

(as high [OH-])

→ Fast reaction rate

(as high [OH-])

Examples of Strong bases

→ NaOH

→ KOH

→ Any metal hydroxide

Question 7

Weak bases

Answer 7

2. Weak bases→ have partially reacted with waterhave a low K value (Kb) - so [low] of products, OH-Equilibrium lies to the left - so lots of reactantsWeak bases have:→ Poor conductivity(as low [ions])→ Lower PH (still?)(as lower [OH-])→ Slow reaction rate(as low [OH-])Examples of weak bases→ NH3→ Amines→ HBr