7. All about water Flashcards Preview

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Flashcards in 7. All about water Deck (21)
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1
Q

What type of bonding exists in water?

A

Covalent molecular

2
Q

What is the molecular formula of water?

A

H 2 O

3
Q

What shape is the water molecule?

A

Angular

4
Q

What is meant by a polar molecule?

A

A molecule which has a separation of charge within it

5
Q

Why is water a polar molecule?

A
6
Q

What types of substances dissolve in water?

A
  • ionic compounds
  • polar molecules
7
Q

What is an electrostatic attraction?

A

An attraction between 2 opposite (+ve and -ve) charges,

8
Q

What is the attraction between water molecules?

A

An electrostatic attraction between the as shown by dashed line in diagram

9
Q

How do some water molecules get ionised?

A

The electrostatic attraction between molecules can cause one to break into 2 ions

10
Q

Why does water conduct if it is covalent molecular substance?

A

Because some water molecules break into ions which are free to move in solution.

11
Q

Why is pure water a poor conductor?

A

Beacuse the concenmtration of ions in solution is always very small

Around 1 in 500 million are ionised at any one time

12
Q

What are the 2 ions that water breaks into?

A
13
Q

What is the alkaline ion?

A

Hydroxyl (OH- (aq) ) ion

14
Q

What is the acid ion?

A

Hydrogen (H+ (aq) ) ion

15
Q

Why does water have a pH of 7?

A

Because it ionises to produce equal numbers of H+ (aq) and OH- (aq) ions.

16
Q

What is an “acidic oxide”

A

A NON-METAL oxide that is soluble in water

17
Q

What is an “basic oxide”

A

A METAL oxide that is soluble in water

18
Q

What is a pollutant?

A

A harmful substance released into the environment

19
Q

What is acid rain?

A

Rain which falls with a pH of below 5.6

20
Q

How do pollutants contribute to acid rain?

A
21
Q

What are the 2 main pollutants that cause acid rain?

A

Sulphur dioxide

Nitrogen oxides