Production And Uses Of Substances In Relation To Properties

Question 1

How do you work out percentage yield?

Answer 1

Actual amount/possible amount*100

Question 2

What did Dmitri Mendeleev do?

Answer 2

Arranged elements in atomic number (proton number)

Put elements with same properties together under each other

Look at patterns

Question 3

Ionisation energy

What happens across a period?

Answer 3

Proton number increases therefore
Electronegativity increase therefore
Energy to remove an electron (work function) increases

Question 4

What does work function mean?

Answer 4

The energy needed to give to an electron to remove it from the element

Question 5

Ionisation energy- What happens down a group?

Answer 5

A new energy level is added therefore
Outer electrons are further away and more shielding therefore
Require less energy to remove an electron

Question 6

What happens to ionsation energy across a period?

Answer 6

Across a period more electronegativity so more work function

Question 7

What happens to atomic radius in periodic table?

Answer 7

Decreases with more protons but

increases with energy levels added

Question 8

What happens to ionic radius in periodic table?

Answer 8

Same as atomic radius but
Cations are behind by one element
Anions are ahead one element

Question 9

What happens to electronegativity in periodic table?

Answer 9

Add protons increases but

Gain shells decreases

Question 10

What is electron affinity

Answer 10

It’s like electronegativity

Question 11

What happens with M.P and B.P across periods in metals and why?

Answer 11

All metals have low electronegativity therefore electrons can dissociate from nucleus

Web of electrons/metallic bonds

Left to right it increases, cause increasing electronegativity, cause more protons

The web of bonds become stronger so more energy to break them

Question 12

What happens with M.P and B.P across periods in metalloids (in the middle) and why?

Answer 12

Boron and carbon had high M.P and B.P due to large lattice structures

Lots of Colavent bonds with a hint of metallic

Question 13

What happens with M.P and B.P across periods in the left side/gases and why?

Answer 13

Increasing electronegativity, tighter electron clouds which makes molecules smaller

This weakens London dispersion forces as they have to get closer to have an interaction between molecules

Question 14

What does ductile mean?

Answer 14

Being able to turn it into a thin wire

Question 15

What does the graph for ionisation energy look like?

Answer 15

It increases across periods and then decreases down a group so the graph goes up and then down and then up again across the period

Question 16

What happens to melting and boiling point in metals across a periodic table?

Answer 16

Across a period it increases as electronegativity increases

Question 17

Why do metalloids have high m.p and b.p

Answer 17

Metalloids have high m.p and b.p because of the strong bonds they form with other atoms

Carbon makes giant structures

Colavent bonds with a hint of metallic bonding

Question 18

Why do non-metals have low m.p and b.p?

Answer 18

They make small molecules because Van Der Waals forces are weak

Question 19

What is electron affinity?

Answer 19

The ability of nucleus to grab a passing electron e.g electronegativity

Question 20

What happens to reactivity across groups

Answer 20

The first groups have high reactivity because it has low electronegativity

Transition metals have middle electronegativity so it can’t gain or lose an electron easily

Right groups (3 to 7) increases as high electronegativity

Noble gases (group 8) full outer shell so doesn’t react

Question 21

What is the reaction formula of metal with water?

Answer 21

Metal + water —⟩ hydroxide + hydrogen

E.g
2Li + 2H2O —⟩ 2Li2O

Question 22

What is the reaction formula of metal with oxygen?

Answer 22

Metal + oxygen —⟩ metal oxide

4 Li + O2 —⟩ 2Li2O

Question 23

What is the reaction formula of metal with acid?

Answer 23

Metal + acid —⟩ metal salt + hydrogen
2Li + 2HCl. —⟩ 2LiCl + H2
Sulfate —⟩ Li sulfate+ H

Question 24

What does salt mean?

Answer 24

Ionic bonding between metal and non metal

Question 25

What is the reaction formula of metalloid with water?

Answer 25

Metalloid + water —⟩ no reaction

Question 26

What is the reaction formula of metalloid with oxygen?

Answer 26

Metalloid + oxygen —⟩ metalloid dioxide

Carbon + oxygen —⟩ carbon dioxide

Question 27

What is the reaction formula of metalloid with hydrochloric acid

Answer 27

Metalloid + hydrochloric acid —⟩ metalloid chloride + hydrogen

Carbon + hydrochloric acid —⟩ carbon chloride + hydrogen

Weak reaction

Carbon chloride decomposes as carbon doesn’t give or take electrons easily

Question 28

What do non metals do with oxygen?

Answer 28

Make small molecules e.g NO2

Gases are held together by Van den Waals forces

Question 29

What happens to reactivity down group 1 and why?

Answer 29

As you go down group 1 the electronegativity decreases as more energy levels are added,
so it’s easier for the atom to lose an electron
Therefore reactivity increases

Question 30

What are the factors that reduce yield?

Answer 30

Incomplete reactions

Wasted chemicals

Hydration

Extraction

Side reactions

Question 31

What does OIL RIG mean?

Answer 31

Oxidation
Is
Loss

Reduction
Is
Gain …. Of electrons

Question 32

What is the oxidation state of all elements?

Answer 32

Zero, as the number of protons and electrons are the same

Question 33

What is redox?

Answer 33

Where a reaction has both oxidation and reduction take place

Question 34

What happens to ionic radius of cations across periods?

Answer 34

It decreases, it gets smaller but one element ahead of normal atomic radius

Question 35

What does amphoteric mean?

Answer 35

A substance that can act as both an acid and a base

Question 36

What are allotropes?

Answer 36

Allotropes refer to when an element forms different physical forms
e.g. graphite and diamond are allotropes of carbon

Question 37

What is a half equation?

Answer 37

An equation that shows the loss or gain of electrons during a reaction

Question 38

What does oxidation number mean

Answer 38

the number of electrons an element has lost or gain

this number can be positive or negative depending on how many electrons, the element has lost or gained

Question 39

What are oxidising agent?

Answer 39

Substances that take electrons from other atoms or ions

Halogens are oxidising agents

Question 40

Why are transition metals unreactive?

Answer 40

the electronegativity in metals is too weak to steal electrons from other atoms

and is too strong for the electrons to be lost to other elements

Question 41

Why do metals have different oxidation states?

Answer 41

Metals have 4s and 3d electrons

Unpaired electrons can be removed easily therefore different oxidation states

Question 42

Why can Manganese have oxidation states between +2 and +7

Answer 42

Because Mn can lose electrons in 4s and 3d orbitals and sub-shells

The electrons that are further away from nucleus and unpaired are easily loss

This means Mn can lose multiple electrons

Question 43

What happens when you dissolve a metal oxide?

Answer 43

You get a alkaline solution and metal hydroxide

Question 44

What happens when you dissolve a non-metal oxide?

Answer 44

You get a acid solution

Question 45

Why do metals tarnish?

Answer 45

Metals react with oxygen in the air and form metal oxide

Question 46

A piece of sodium is place into water

What would you observe?

Answer 46

The sodium would react with the water quite aggressively, it would fizz in the water

It would make a alkaline solution