chem pathway

Question 1

describe what is meant by simple distillation

Answer 1

Simple distillation separates liquids based on their boiling points by heating, vaporizing the lower-boiling component, and condensing it for collection.

Question 2

describe how simple distillation works

Answer 2

• Heat the mixture to its boiling point.
• The component with the lower boiling point vaporizes first.
• The vapor is then cooled and condensed back into liquid form.
• The purified liquid is collected in a separate container.

Question 3

I can describe how fractional distillation can be used to separate a mixture of liquids

Answer 3

Fractional distillation separates a mixture of liquids by repeatedly vaporizing and condensing to isolate components based on their differing boiling points.

Question 4

Positive ions are usually created when…

Answer 4

…an atom or molecule loses electrons.

Question 5

what are Positive ions also called

Answer 5

Positive ions are also called cations.

Question 6

Negative ions are usually created when…

Answer 6

…an atom or molecule gains electrons.

Question 7

What is another name for negative ions?

Answer 7

Anions

Question 8

Ions can be made up of:

Answer 8

1 atom (e.g. F-).
Combinations of atoms with an overall charge (e.g. SO42-).

Question 9

noble gasses (3)

Answer 9

• Noble gases already have a full outer shell.
• Noble gases are unreactive
• don’t normally form ionic bonds with other elements.

Question 10

what does the group number in the periodic table tell you.

Answer 10

the number of electrons in an atom’s outer electron shell.

Question 11

Cation

Answer 11

Positively charged ion formed by losing electrons.

Question 12

Positively charged ion formed by losing electrons.

Answer 12

Cation

Question 13

Anion

Answer 13

Negatively charged ion formed by gaining electrons.

Question 14

Negatively charged ion formed by gaining electrons.

Answer 14

Anion

Question 15

Materials with ionic bonds usually:

Answer 15

• have high melting pint
• only conduct electricity when molten/dissolved

Question 16

how can we show the transfer of electrons, and the ions formed

Answer 16

using dot-and-cross diagrams.

Question 17

when does an ionic compound form

Answer 17

forms when million of metal atoms transfer their outer electrons to millions of non metals at the same time. This resulting oppositely charged ions are held together in ionic lattices.

Question 18

what are ionic lattice

Answer 18

giant structures that are held together by strong electrostatic forces between the
+ and - ions

Question 19

electrostatic forces

Answer 19

the electrostatic forces are called ionic bond and they extend in all directions

Question 20

What type of forces hold ionic lattices together?

Answer 20

electrostatic forces

Question 21

What is the empirical formula of sodium oxide?

Answer 21

Establish what ions are formed by each component of the ionic compound.
- Na atom → Na+ ion.
- O atom → O2- ion.

Calculate the simplest ratio of these 2 ions that results in a net charge of zero.
- Na+ : O2- = 2 : 1.

Convert this ratio into a formula.
- Na2O.

Question 22

If an ionic compound contained Mg2+ and O2- ions, what would the empirical formula be?

Answer 22

MgO

Question 23

how is diamond a giant covalent structure?

Answer 23

Every carbon atom in diamond is bonded to 4 other carbon atoms by strong covalent bonds.

Question 24

how is diamond hard?
and because this what is it used for?

Answer 24

There are lots of strong covalent bonds in diamond. This makes it very hard.
Because diamond is hard, it is used as a cutting tool to cut other materials.

Question 25

does diamond conduct electricity? and why?

Answer 25

Diamond is NOT an electrical conductor because there are no delocalised electrons in the diamond structure.