Acids and base

Question 1

HCl

Answer 1

Acid

Question 2

H2SO4

Answer 2

Acid

Question 3

HNO3

Answer 3

Acid

Question 4

CH3COOH

Answer 4

acid

Question 5

KOH

Answer 5

Base

Question 6

NaOH

Answer 6

Base

Question 7

Ba(OH)2

Answer 7

Base

Question 8

What is the general equation for a neutralisation reaction?

Answer 8

Acid+ base —>salt + water

Question 9

When an acid + metal react what do they form?

Answer 9

Salt+ hydrogen

Question 10

When an acid and metal oxide react what do they form?

Answer 10

Salt + water

Question 11

When an acid and metal carbonate react, what do they form?

Answer 11

Salt + carbon dioxide + water

Question 12

What is the Arrhenius model?

Answer 12

Acids and bases are defined based on how they dissolve in water.

Question 13

Arrhenius acids?

Answer 13

Dissociate to give
H+ ions

Question 14

Arrhenius bases?

Answer 14

Dissociate to give
OH- ions

Question 15

What is the brondsted Lowry model?

Answer 15

Acids and bases are defined based on how they react

Question 16

Bronsted Lowry acid?

Answer 16

Proton donator

Question 17

Bronsted Lowry base?

Answer 17

Proton acceptor

Question 18

Define acidity?

Answer 18

Concentration of H+ ions

Question 19

How do you find pH?

Answer 19

pH= -log10[H+]

Question 20

How do you find concentration of H+ ions form pH?

Answer 20

[H+]=10^-pH

Question 21

What does water dissociate into?

Answer 21

H2O=H+ + OH-

Question 22

What is the equilibrium constant for water dissociation?

Answer 22

Kw
(Ionic product of water)

Question 23

What unit does Kw have?

Answer 23

Mol2 dm-6

Question 24

How does temperature affect pH?

Answer 24

The ionisation of water is endothermic. So increasing the temperature shifts the equilibrium to the right. This increases the concentration of H+ ions and so decreases the pH.

Question 25

Explain how Kw increases as temperature increases?

Answer 25

The ionisation of water is endothermic p so increasing temperature shifts the equilibrium to the right. This increases the concentration of H+ and OH- ions, which increases Kw.

Question 26

How does the low solubility of some group 2 hydroxide affect pH?

Answer 26

Some group 2 has low hydroxides have low solubility as a result salts don’t fully dissolve and leading to a pH value which isn’t always as high as expected.

Question 27

Why is water always neutral?

Answer 27

As the concretatuon of OH- and H+ ions are equal

Question 28

When weak acids dissociate what do they form?

Answer 28

Dynamic equilibrium

Question 29

What is the equilibrium constant for this reaction?

Answer 29

Ka (Acid dissociation constant

Question 30

What is the unit for Ka?

Answer 30

Mol dm-3

Question 31

The larger the Ka for an acid….

Answer 31

The stronger the acid

Question 32

To make it easier to compare Ka values what is used

Answer 32

pKa value is used

Question 33

How do you find pKa?

Answer 33

pKa =-log(Ka)

Question 34

How do you find Ka from pKa?

Answer 34

10-pKa

Question 35

The smaller the pKa value..

Answer 35

The stronger the acid is

Question 36

What is an monoprotic acid?

Answer 36

Produces 1 proton.

Question 37

Examples of monoprotic acids

Answer 37

HCl HNO3 CH3COOH

Question 38

What is a diprotic acid?

Answer 38

Produces 2 protons

Question 39

Examples of diprotic acids

Answer 39

H2SO4

Question 40

What is a triprotic acid?

Answer 40

Produces 3 protons

Question 41

Which proton dissociates strongly?

Answer 41

1st proton

Question 42

Which proton dissociates weakly ?

Answer 42

2nd and 3rd

Question 43

How do you find pH after a neutralisation reactions?

Answer 43

Find which reactant is in excess. Calculate the amount of the excess reactant once the reaction is complete. Use your answer to step 2 alongside the volume to find concentration of [H+]or [OH-]. Find pH.

Question 49

What is a buffer solution?

Answer 49

A buffer solution resists changes in pH when small amounts of acid or base are added.

Question 50

What do buffer solutions contain?

Answer 50

Must containHA and A- The concentration of HA and A- must be high.

Question 51

How to make a buffer solution?

Answer 51

Mixing a weak acid with the salt of its conjugate base. Or partially neutralising a weak acid with a strong base.

Question 52

Equation of a buffer solution.

Answer 52

HA= H+ + A-

Question 53

What happens when small amounts of acid or base are added to the buffer?

Answer 53

The equilibrium position shifts to maintain the concentration of H+.

Question 53

Adding acid to a buffer solution

Answer 53

Adding HCl increases the concentration of H+ ions which makes the equilibrium shift to the left. This decreases the concentration of H+

Question 54

Adding a bases to a buffer solution.

Answer 54

Add NaOH. OH- + H+—>H2O this decreases the concentration of H+ ions so the equilibrium shifts to the right. D increase the concentration of H+