Chapter 4 - Acids and REDOX

Question 1

all acids contain what?

Answer 1

hydrogen in their formulae

Question 2

when dissolved in water, acids release ?

Answer 2

hydrogen ions as protons - H (^+)

Question 3

strong acid def

Answer 3

releases all hydrogen atoms into solution as H plus ions and COMPLETELY DISSOCIATES in aqueous solutuion

Question 4

weak acid def?

Answer 4

only releases a small proportion of its available H atoms into solution as H plus ions. PARTIALLY DISSOCIATES in aqueous sol

Question 5

weak acid have ?

Answer 5

a forwards/ backwards arrow (equilibrium sign) which indicates that the forwards reaction is incomplete

Question 6

most organic acids, like ethanoic acid are ____ acids

Answer 6

weak

Question 7

a base…

Answer 7

neutralises an acid to form a salt

Question 8

what is an alkali?

Answer 8

a base that dissolves in water realising hydroxide ions into the solution

Question 9

how do strong acids containing more than one H atom behave?

Answer 9

strong acid for only one H atom

next H acts as weak acid

Question 10

What is a titration?

Answer 10

a technique used to accurately measure the volume of one solution that reacts exactly with another solution

Question 11

what can titrations be used for?

Answer 11

• finding the conc of a solution
• identification of unknown chemicals
• finding the purity of a substance

Question 12

burette readings always have ___ decimal places

Answer 12

2 - with the last place being either 0 or 5

Question 13

concordant results

Answer 13

are within 0.1cm (^3) of each other

Question 14

acids are?

Answer 14

proton donors bc they donate H(+) ions to bases

Question 15

ammonia is a ?

Answer 15

weak base and forms a weakly alkaline solution when dissolved in water

Question 16

strength of acids - what is strength?

Answer 16

a measure of dissociation

Question 17

a strong acid easily gives up ?

Answer 17

protons, but a weak acid does not easily give up protons

Question 18

strong base definition

Answer 18

is fully ionic.

100% splits up into metal ions and hydroxide ions in solution

Question 19

weak base definition

Answer 19

doesn’t convert fully into hydroxide ions in solution

Question 20

in neutralisation, the h(+) ion is replaced by?

Answer 20

a metal ion or any other + ion

Question 21

interesting cases - acidic salts?

Answer 21

• formed from polyprotic acids

e. g. salts of sulphuric acid

Question 22

what is a polyprotic acid?

Answer 22

• an acid that dissociates more than once - it donates more than 1 proton

Question 23

interesting cases - ammonium salts?

Answer 23

• formed when acids are neutralised by aqueous ammonia

- salts formed contain the NH four (+) ion

Question 24

Explain how OH minus acts as a base?

Answer 24

the Oh minus ion accepts a proton

Question 25

explain why Kcl can be referred to as a salt?

Answer 25

the H plus ion in Hcl has been replaced by a metal ion

Question 26

Common acids and their uses?

Answer 26

Hcl - stomach acid Sulphuric acid - car batteries Nitric acid - fertiliser

Question 27

Bases are _____, _______, ________

Answer 27

Oxides, hydroxides and carbonates of metals

Question 28

When converting into ionic equations,

Answer 28

Discount unchanged ions as tgesd re spectator ions

Question 29

2 H[^+] + 2 OH [^-]

Answer 29

-> 2H (two) 0

Question 30

Solute definition

Answer 30

The solid that is being dissolved

Question 31

Solvent definition

Answer 31

The liquid that the solute is dissolved in

Question 32

Solution definition

Answer 32

A mixture of the solute and solvent

Question 33

How many sig figures?

Answer 33

Usually 3sf but look at data and use smallest amount as if bigger no. Of sig figs, you're saying your data is more accurate

Question 34

Scaling equation?

Answer 34

Moles × (volume scaling to / volume we have)

Question 35

oxidation can occur both in terms of ____ and ______

Answer 35

oxxygen, electrons

Question 36

oxidation (oxygen)?

Answer 36

gain of oxygen

Question 37

reduction (oxygen)?

Answer 37

loss of oxygen

Question 38

oxidation (electrons)?

Answer 38

loss of electrons

Question 39

reduction (electons)?

Answer 39

gain of electron s | OIL RIG

Question 40

roman numerals are used to?

Answer 40

represent the oxidation state pf an element | espec. important when element has more than 1 possible oxidation no.

Question 41

what can have more than one possible oxidation number?

Answer 41

- Transition elements - Oxyanions - end in ATE, composed of an element and oxygen - e.g. nitrate

Question 42

what is a redox reaction?

Answer 42

a reaction where both oxidation and reduction are occurring in the same reaction

Question 43

oxidation is an _____ in oxidation number

Answer 43

increase

Question 44

reduction is a _____ in oxidation number

Answer 44

decrease

Question 45

disproportionation reduction?

Answer 45

reactions where the same elements are both oxidised and reduced

Question 46

oxidation rules - elements?

Answer 46

oxdiation state of element = 0

Question 47

oxidation rules - monatomic ions?

Answer 47

have lost or gained electrons

Question 48

oxidation rules - hydrogen?

Answer 48

is +1 except in hydrides

Question 49

oxidation rules- bonds in a molecule between the same element?

Answer 49

IGNORE

Question 50

oxidation rules - oxygen?

Answer 50

-2 except in peroxides (a compound containing two oxygen atoms bonded together in its molecule or as the anion O22−) and if bonded to fluorine

Question 51

oxidation rules - which atom is negative?

Answer 51

the most electronegative (closest to fluorine)

Question 52

the sum of all ON =?

Answer 52

0