Acids Bases And Ph

Question 1

Bronsted Lowry‘s model for acids and bases

Answer 1

Bronsted Lowry‘s acid is a proton donor

Bronsted Lowry‘s base is a proton acceptor

Question 2

Monobasic acid

Answer 2

Has one hydrogen ion per molecule that can be replaced by metal ions or ammonium during neutralisation

Question 3

Dibasic acid

Answer 3

Has two hydrogen ions per molecule that can be replaced

Question 4

Tribasic

Answer 4

Three hydrogen ions can be replaced per molecule by metal ions or ammonium ions to form a salt

Question 5

Conjugate acid-base pairs

Answer 5

They contain two species that can be interconverted by transfer of a proton

Question 6

Conjugate acid

Answer 6

The acid that donates a proton to a base

Question 7

Conjugate base

Answer 7

Base that accepts A proton from an acid

Question 8

What condition is required for dissociation to take place

Answer 8

The presence of water

Question 9

H30+ is also known as

Answer 9

The hydronium ion

Question 10

pH definition and mathematical expression

Answer 10

pH is a measure of the concentration of H+ ions in solution

pH= -log[H+(aq)]

Question 11

A small value of pH suggests there is a ….. concentration of H+ ions

Answer 11

Large
So it is quite acidic

Question 12

On the base 10 logarithmic scale , a change in pH by one unit is equivalent to

Answer 12

A 10x change in the concentration of hydrogen ions

Question 13

Mathematic expression for the concentration of hydrogen ions(the formulae ) from the ph

Answer 13

[H+(aq)]= 10^-pH

Question 14

For a strong monobasic acid , what is the ratio of moles of the acid to the hydrogen ions and what does this suggest

Answer 14

1:1
It suggests that the concentration of the acid and hydrogen ions are the same

Question 15

Acid dissociation constant symbol

Answer 15

K little a(Ka)

Question 16

The further right the position of equilibrium of in weak acid

Answer 16

The stronger the weak acid

Question 17

Formulae of pKa

Answer 17

pKa= -logKa

Question 18

Formulae for Ka using pKa

Answer 18

Ka = 10^-pKa

Question 19

Are acids with a Ka value or pKa value weak or strong

Answer 19

They are weak

Question 20

What are the two approximations for weak acids

Answer 20

The concentration of hydrogen ions is the same as the concentration of the conjugate base
[H+]= [A-]

The concentration of the acid at equilibrium is equal to the concentration of the acid at the start

Question 21

What does Kw stand for

Answer 21

The ionic product of water

Question 22

Formulae for Kw

Answer 22

Kw = [H+][OH-]

Question 23

Is Kw temperature dependent?
What is Kw at 298K or 25degrees

Answer 23

Yes

1*10^-14mol^2dm^-6

Question 24

Water is neutral , what does this imply during dissociation of water

Answer 24

It implies that
[H+]= [OH-]

Question 25

What happens to the ph value of the neutral point when temperature changes and why

Answer 25

It changes as well
Because Kw is temperature dependent

Question 26

Approximation for strong monobasic acids

Answer 26

[HA]= [H+]

Question 27

Formular to find new concentrations of acid

Answer 27

Original concentration * (volume of reagent/total volume)

Question 28

The larger the Ka value, the ……. The weak acid

Answer 28

Stronger

Question 29

The smaller the pKa value, the…. The weak acid

Answer 29

Stronger

Question 30

Pure water is neutral at any temperature , true or false

Answer 30

True

Question 31

Two requirements to calculate the ph of a strong base

Answer 31

The concentration of the base
The ionic product of water