C4.3

Question 1

Why can’t a solid ionic compound conduct electricity?

Answer 1

The ions cannot move.

They are fixed in the regular arrangement

Question 2

What happens when an ionic crystal melts?

Answer 2

Because the ions can now move around independently,the molten compound conducts electricity

Question 3

When an ionic crystals dissolves in water

Answer 3

It can now conduct electricity because its ions can move independently among the water molecules

Question 4

How do you work out the formulae of ionic compounds when given the charges on the ions

Answer 4

Swap them
E.g
Al3+ S2-
Al2S3

Question 5

How do you work out the charge on one job when given the formula of a salt and the charge on the other ion?

Answer 5

Total must equal 0.
E.g:-
MgO
If O= 2-
Mg- must be 2+
(Equals 0)

Question 6

What charge do group 1 elements tend to form and why?

Answer 6

Protons give it a 1+ charge.

More likely to lose electron (negative) so have more protons in nucleus than electrons outside.

Question 7

What charge do group 7 elements tend to form and why?

Answer 7

1- charge.

More likely to gain 1 electron than lose any,gains 1 electron so 1 negative charge…: forms a -

Question 8

Compounds of group 1 metals with group 7 elements are what?

Answer 8

Ionic

Question 9

What happens when an ionic crystal is heated

Answer 9

ions move so much that they can no longer stay in the regular arrangement.