Acids and bases

Question 1

What can acids be neutralised by?

Answer 1

Metal hydroxides (alkalis)
Metal oxides
Metal carbonates

Question 2

What is always produced during neutralisation?

Answer 2

A salt and water and a metal carbonate produces CO2(g) as well

Question 3

What is a salt formed from?

Answer 3

Positive ion of the base and the negative ion of the acid

E.g.
SODIUM hydroxide + hydroCHLORIC acid —> sodium chloride + water

Question 4

What can a titration be used for?

Answer 4

Calculate experimentally the concentration of an acid or alkali. At the end point the number of moles of the H+ ions must equal the number of moles of the OH- ions.

Number of acid moles = number of alkali moles

Question 5

q
What do some acids / alkalis have more than one of?

Therefore…

Answer 5

H+/OH- ions

PVC acid = PVC alkali

P =number of H+ or OH- ions

Question 6

Titrations are repeated until what…

Answer 6

Two results are concordant -they are within 0.2cm3 of eachother- an average of these Is then calculated to get the average titre

Question 7

Chemical formula for hydrochloric acid?

Answer 7

HCl

Question 8

Chemical formula for sulfuric acid?

Answer 8

H2SO4

Question 9

Chemical formula for nitric acid?

Answer 9

HNO3

Question 10

How can we check if a solution is an acid or alkali?

Answer 10

use universal indicator -universal indicator changes the colour of the solution depending wether or no it is an act or an alkali -

Question 11

What pH range does acids have?

Answer 11

1-6
red/orange

Question 12

pH of neutral

Answer 12

7
pale green

Question 13

pH range of alkalis

Answer 13

8-14

green/blue

Question 14

Definition of pH

Answer 14

pH is a number which indicates how acidic or alkaline a substance is

Question 15

Strongest acid and alkaline pH

Answer 15

Acid:1
Alkaline:14

Question 16

How are some common acids made

Answer 16

Some common acids are made by dissolving non metal oxides in water

Question 17

What acids when dissolved in water in the atmosphere cause acid rain

Answer 17

Carbon oxide
Sulfur
Nitrogen

Question 18

How are alkalis formed

Answer 18

by dissolving soluble metal oxides

Question 19

What is the ionic formula of hydrochloric acid

Answer 19

H+(aq)+Cl-(aq)

Question 20

What is the ionic formula of sulphuric acid

Answer 20

2H+(aq) + S42-(aq)

Question 21

What is the ionic formula of nitric acid

Answer 21

H+(aq)+NO3-(aq)

Question 22

What will happen if water is added to an acid

Answer 22

the pH will increase

Question 23

What will happen if water is added to an alkaline

Answer 23

the pH will decrease

Question 24

What is special about acidic solutions

Answer 24

all acidic solutions are ionic and thus they can conduct electricity when they dissolve in water

Question 25

What do all acids contain

Answer 25

H+ ions

Question 26

Give an example of what happens when the acid HCl (aq) dissolves in water

Answer 26

HCl(aq) —> H+(aq) + Cl-(aq)

Question 27

What is a reduction reaction

Answer 27

the gain of electrons (electrons will be on left side of arrow)

Question 28

What is an oxidation reaction

Answer 28

loss of electrons (electrons on the right side of the arrow)

Question 29

What is pH dependent on

Answer 29

pH is dependent on the concentration of hydrogen ions in the solution

Question 30

What does water do

Answer 30

water naturally slightly dissociates (dissociates means breaking up) into an equal amount of hydrogen (H+) and hydroxide ions (OH-)

Question 31

Equation for the disassociation of water

Answer 31

H2O—> H+ + OH-

Question 32

Why does water dilute an acid

Answer 32

it increases the OH- to H+ ratio

Question 33

Why does water dilute an alkaline

Answer 33

It increases the H+ to OH- ratio

Question 34

Tell me what do acids have more of

Answer 34

acids are solutions containing a greater concentration of Hydrogen ions than hydroxide ions

Question 35

Tell me what do alkaline have more of

Answer 35

alkaline are solutions containing a greater concentration of hydroxide ions than hydrogen ions

Question 36

Tell me what does water have

Answer 36

water is a neutral solution containing an equal concentration of hydrogen and hydroxide ions

Question 37

Properties of acids

Answer 37

all acids can be corrosive if they are concentrated enough meaning when they react with something they will break that substance up the higher the concentration the more corrosive the acid is

Question 38

What are the affects of acid rain on buildings

Answer 38

corrodes stone on buildings such as limestone and marble tarnishes glass, rubber and steel destroys brickwork and statues

Question 39

What are the affects of acid rain on fish

Answer 39

it suffocates the fish acid kills fish eggs due to the protecting skin being destroyed by acid the young fail to live

Question 40

What are the affects of acid rain on iron structures

Answer 40

iron structures are corroded and the rate of reaction of rusting increases weakening the structures

Question 41

What are the affects of acid rain on trees

Answer 41

soil becomes infertile and sparse lack of timber three quarters of forests die as they are harmed by acid in the ozone leafs fall off and weaken trees trees get stunted interrupts photosynthesis

Question 42

What are the main sources of acid rain?

Answer 42

power plants combusting coal and oil omits the gas cars, trucks and buses decaying vegetation volcanic eruptions as they release sulphur

Question 43

What is neutralisation

Answer 43

this is when one adds a base to an acid this means that the amount of hydrogen ions decreases until the number of hydrogen ions is the same as in water

Question 44

What are the three bases

Answer 44

metal hydroxides (alkalis) metal oxides (alkalis) carbonates

Question 45

Show a neutralisation reaction formula

Answer 45

H+(aq) + OH-(aq) —->H2O(l)

Question 46

What is produced in a neutralisation reaction

Answer 46

When an acid is neutralised by an alkaline salt and water are formed and when neutralised by a carbonate salt and water and CO2 are formed

Question 47

How do we work out what salts are produced in a neutralisation reaction?

Answer 47

use first work of the alkali and then use the following for labelling acids Hydrochloric acid - chloride sulphuric acid - sulphate nitric acid - nitrate phosphoric acid - phosphate

Question 48

What are spectator ions

Answer 48

ions that are on both sides of the equation

Question 49

what can an alkaline be used for

Answer 49

It is possible to use an alkaline to help work out the exact concentration of an acid this procedure is called. titration an is a more accurate experiment than the one you have just carried out

Question 50

what does a reaction between a metal oxide and an acid produce

Answer 50

salt and water

Question 51

what does a reaction between a metal hydroxide and an acid produce

Answer 51

salt and water

Question 52

what does a reaction between a metal carbonate and an acid produce

Answer 52

salt, water and carbon dioxide

Question 53

what are the spectator ions in this equation - N+Cl+Na+OH-->Na+Cl+H2O

Answer 53

Na+Cl

Question 54

what is a standard solution (titration)

Answer 54

a solution of accurately known concentration.

Question 55

what is an indicator used for (titration)

Answer 55

to show when the end point of the reaction has been reached.

Question 56

when are titre volumed deemed concordant

Answer 56

when the measurements are between 2cm^3.