Chapter 4: Acids and redox

Question 1

what is the main characteristic of an acid

Answer 1

acids donate H+(aq) in aqueous solution

Question 2

what does a strong acid do

Answer 2

strong acid dissociates fully there H+ ions

Question 3

what is a monoprotic acid

Answer 3

acid that breaks up and dissociates to form one proton

Question 4

what is a diprotic acid

Answer 4

acid that breaks up and dissociates to form two proton

Question 5

what is a tripotic acid

Answer 5

acid that breaks up and dissociates to form three protons

Question 6

what does concentrated and dilute refer to in acids

Answer 6

refers to how much acid there is in a set volume

Question 7

what is the pH scale in terms of mathematical formula

Answer 7

pH = -log[H+]

Question 8

what is a weak acid

Answer 8

acid that only partially dissociates in aqueous solution

Question 9

what is a Base

Answer 9

substance that neutralises an acid and accepts H+ ions to form water and salt

Question 10

what is an alkali

Answer 10

a base that dissolves to form OH-(aq) ions

Question 11

what is the general neutralisation formula

Answer 11

Acid + base –> Salt + Water + (Carbon Dioxide)

Question 12

what do titrations always need

Answer 12

Aqueous solution

Question 13

what is a spectator ion

Answer 13

it is an ion that during the reaction nothing happens to

Question 14

what does an ionic equation do

Answer 14

get rid of spectator ion and show what is actually happening during the reaction

Question 15

what is the first step for writing an ionic equation

Answer 15

write a ‘normal’ balanced equation

Question 16

what is the second step for writing an ionic equation

Answer 16

ionic compounds in aqueous solution will split into separate hydrated ions which react independently

Question 17

what is the third step for writing an ionic equation

Answer 17

look for the spectator ions and remove from the equation

Question 18

what are the two things you do to spot the spectator ions

Answer 18

are they in an aqueous solution
are they unchanged
if yes to both they are spectator ions

Question 19

what is the fourth step for writing an ionic equation

Answer 19

write out the remaining ionic equation with state symbols

Question 20

what is quantitative analysis

Answer 20

all about measuring amounts then analyse and evaluate date

Question 21

what is volumetric analysis

Answer 21

involves using volumes

Question 22

what is the percentage purity formula

Answer 22

(mass of pure substance / mass of impure sample) x 100

Question 23

what is a REDOX reaction

Answer 23

a reaction where both oxidisation and reduction happen

Question 24

what is an ionic half equation

Answer 24

where you split an ionic equation in half to show what is happening to each ion

Question 25

what is an Oxidising Agent

Answer 25

A chemical species that causes something else to be oxidised and is itself reduced

Question 26

what is a Reducing Agent

Answer 26

A chemical species that causes something else to be reduced and is itself oxidised

Question 27

what are Oxidation Numbers

Answer 27

Theoretical numbers of electrons involved in bonding of an atom to a separate element, whether ionic or covalent

Question 28

what is the element oxidation number

Answer 28

any element in its elemental form has an oxidation number of 0

Question 29

what is the simple ion oxidation number rule

Answer 29

in a simple ion the oxidation number is equal to the charge

Question 30

what does an increase in the oxidation number mean

Answer 30

the element is being oxidised

Question 31

what does a decrease in the oxidation number mean

Answer 31

the element is being reduced

Question 32

what is the compound oxidation number rule

Answer 32

in a compound the total oxidation number of each atom add up to 0

Question 33

what is the complex ion oxidation number rule

Answer 33

in a complex ion the oxidation numbers of all the atoms add up to the remaining charge

Question 34

what do Roman numerals in Chemistry represent

Answer 34

Roman numerals show the oxidation number where an element can have more than one oxidation state

Question 35

what are the three special cases for oxidation states

Answer 35

>Hydrogen in metal hydrides >Oxygen in peroxides >Halogens can vary

Question 36

explain how metal hydrides are special cases for oxidation states

Answer 36

Hydrogen has a negative oxidation number | e.g. NaH H has an oxidation state of -1

Question 37

explain how peroxides are special cases for oxidation states

Answer 37

Oxygen has an oxidation state of -1 | e.g. H2O2 Oxygen has an oxidation number of -1

Question 38

explain how halogens are special cases for oxidation states

Answer 38

Halogen can have varying oxidation state from usual -1 | e.g. HClO Cl has an oxidation state of +1

Question 39

what is disproportionation

Answer 39

where an element is both oxidised and reduced in the same reaction