Topics 3-4

Question 1

What kind of bonds do covalent substances form

Answer 1

Strong covalent bonds to make small molecules of two or more atoms

Question 2

What forces of attractions are between metals with simple molecular structure (covalent substances)

Answer 2

Weak forces

Question 3

Name five factors of simple molecular covalent substances

Answer 3

Weak forces of attraction lead to low melting and boiling points (easily parted)
Gas or liquids at room temp
Don’t conduct electricity (no ions)
Distinguished by physical state ‘mushy’

Question 4

Name three examples of weak inter-molecular forces

Answer 4

Hydrogen
Oxygen
Water

Question 5

Name five characteristics of giant molecular structures

Answer 5

1) ionic lattices with no charged ions
2) atoms bonded by strong covalent bonds
3) high melting and boiling points
4) don’t conduct electricity-even when molten (except graphite)
5) insoluble in water

Question 6

Give two examples of giant molecular structures

Answer 6

Diamonds

Graphite

Question 7

Name properties of diamonds

Answer 7

Each carbon atom forms 4 covalent bonds in rigid covalent structure
Which makes them really hard-excellent cutting tool
Doesn’t conduct electricity as no free electrons

Question 8

What three properties can you identify bonding in a substance by

Answer 8

Ionic lattice
Giant molecular
Simple molecular

Question 9

Name properties of graphite

Answer 9

Each carbon atom forms 3 covalent bonds
Each sheet of carbon slides over each other freely (useful lubricant)
Layers held together loosely (rub of on paper)-pencil
3 of 4 outer electrons used=lots if spare electrons
Good conductor of electricity-used in electrodes

Question 10

Some liquids are ……. And some are …….

Answer 10

Immiscible

Miscible

Question 11

What are I miscible liquids separated by

Answer 11

Separating funnel
Shake and denser liquid will sink to bottom less dense forms a layer on top
Separating funnel and tap, tap drains denser liquid into beaker
E.g oil and water

Question 12

How to separate miscible liquids

Answer 12

Fractional distillation
Must have different boiling points to condense at different temperatures and collect separately
E.g liquid air

Question 13

What can chromatography paper be used for

Answer 13

Identify different substances in a formula

Uses the facts that different substances wash through wet filter paper at different rates

Question 14

What is Rf

Answer 14

Ratio between distance travelled by solvent by the dissolved substance and the distance traveled by solvent

Question 15

What is the calculation for working out Rf

Answer 15

Distance traveled by substance / distance traveled by solvent

Question 16

What is the results of chromatography analysis called

Answer 16

Chromatogram

Question 17

Name two properties of metals

Answer 17

Conduct electricity

Malleable

Question 18

Name three properties of transition metals

Answer 18

High melting points
Form colourful compounds (hair dyes, gemstones, pottery glazes)
Everyday uses

Question 19

Describe the structure of metals and their properties

Answer 19

all have same basic bondings
Regular arrangement of atoms held together by metallic bonds-giving giant structure (positive ions and free electrons
And outer electrons become delocalised
“Sea” of delocalised electrons throughout metal
Good conductors of electricity
High boiling and melting points
Insoluble layers of atoms slide over each other allowing metals to be bent and shaped (malleable)

Question 20

What group are alkali metals

Answer 20

Group one

Question 21

Name 4 characteristics of alkali metals

Answer 21

One electron in outer shell
Very reactive
Soft
Low melting points
React vigorously in water

Question 22

When lithium sodium or potassium are put in water what do they produce

Answer 22

Alkaline solution (blue purple universal indicator)

Question 23

Why are alkali metals more reactive as they go down

Answer 23

Because the outer negatively charged electrons are further away from the positively charged protons in the nucleus therefore they get rid of them easier

Question 24

How can we see that metals are more reactive as you go down

Answer 24

By putting them in water and time how long it takes for the element to completely disappear

Question 25

What do alkali metals react with water to produce

Answer 25

Hydrogen gas

Plus metal hydroxide