ACIDS AND REDOX

Question 1

WHAT IS AN ACID

Answer 1

A proton donor that releases H+ ions in aq solution

Question 2

WHAT IS A STRONG ACID

Answer 2

an acid that fully dissociates in aqueous solution

Question 3

WHAT IS A WEAK ACID

Answer 3

an acid that only partially dissociates in aqueous solution

Question 4

WHAT IS A BASE

Answer 4

a proton acceptor that release OH- ions in aq solution

Question 5

HOW IS A SALT FORMED

x3

Answer 5

a base and an acid
a metal and an acid
a metal and a non metal

Question 6

WHAT IS AN OXIDATION NUMBER

Answer 6

the number of electrons lost or gained to or by a different element

Question 7

WHAT IS REDUCTION

Answer 7

Decrease in oxidation number due to a gain of electrons

Question 8

WHAT IS OXIDATION

Answer 8

Increase in oxidation number due to a loss of electrons

Question 9

what is an alkali

Answer 9

a soluble base

Question 10

Example of a weak acid

Answer 10

ethanoic acid or other carboxylic acids
(CH3COOH)

Question 11

Example of strong acids and formula

Answer 11

Nitric acid (HNO3)
Sulphuric acid(H2SO4)
Hydrochloric acid(HCl)

Question 12

Example of strong bases and formula

Answer 12

sodium hydroxide (NaOH)
Potassium hydroxide(KOH)

Question 13

Example of a weak base

Answer 13

Ammonia(NH3)

Question 14

What is a polyprotic acid and examples of mono, di, tri protic acids

Answer 14

An acid that can donate one or more proton

mono - Nitric acid (HNO3)
di - sulphuric acid (H2SO4)
tri - phosphoric acid (H3PO4)

Question 15

example of formation of a salt from ammonia and an acid

Answer 15

2NH3(aq) + H2SO4(aq) –> (NH4)2 SO4(aq)

no water as by product

Question 16

example equation and ionic equation for metal + acid

Answer 16

Ca(s) + H2SO4(aq) –> CaSO4(aq) + H2(g)
Ca(s) + H+(aq) –> Ca2+(aq) + H2(g)

Question 17

Metal + acid –> ?

Answer 17

Salt + Hydrogen

Question 18

example equation and ionic equation for metal oxide + acid

Answer 18

MgO(s) + 2HCl(aq) –> MgCl2(aq) + H2O(l)
MgO(s) + 2H+(aq) –> Mg2+(aq) + H2O(l)

Question 19

Metal oxide + acid –> ?

Answer 19

Salt + water

Question 20

example equation and ionic for metal hydroxide + acid

Answer 20

2NaOH(aq) + H2SO4(aq) –> Na2SO4(aq) + 2H2O(l)
2OH-(aq) + 2H+(aq) –> 2H2O(l)

Question 21

metal hydroxide + acid –> ?

Answer 21

salt + water

Question 22

Example and ionic equation for metal carbonate + acid

Answer 22

Li2CO3(s) + 2HNO3(aq) –> 2LiNO3(aq) + CO2(g) + H2O(l)
Li2CO3(s) + 2H+(aq) –> 2Li+(aq) + CO2(g) + H2O(l)

Question 23

metal carbonate + acid –> ?

Answer 23

salt + carbon dioxide + water

Question 24

How to set up and perform a titration

Answer 24

Add standard solution(known concentration) of acid or alkali into a burette

add unknown concentration of alkali or acid into conical flask below burette with a few drops of an indicator

titrate into conical flask and swirl until solution changes colour as it has reached the end point

record the titre value to 2 decimal places

repeat titration until you obtain concordant values
( within 0.10cm3 of each other)

Question 25

How to prepare standard solution

Answer 25

Weigh the mass of solid precisely

transfer the solid into a beaker, rinsing weighing boat with deionised water

add deionised water and stir with glass rod until all solid has dissolved, then rinse glass rod into beaker with deionised H2O

transfer solution into volumetric flask and rinse beaker and funnel with deionised water

add deionised water to flask to reach graduation line

then mix solution by inverting flask multiple times

add this solution to burette for titration

Question 26

OILRIG

Answer 26

oxidation is loss reduction is gain

Question 27

What does a reducing agent do

Answer 27

it loses electrons and is in turn oxidised

Question 28

what does an oxidising agent do

Answer 28

it gains electrons and is recued

Question 29

standard oxidation states of :
- Uncombined elements
- ions
- group 1 elements
- group 2 elements
- Aluminium
- Hydrogen
- Chlorine
- Fluorine
- Oxygen

Answer 29

• always 0
• same as ion charge
• +1
• +2
• +3
• +1 (except in hydrides it is -1)
• -1 (except in compounds with F and O)
• -1
• -2 ( except with F or in peroxides it is -1)