Topic 4- Chemical Changes Flashcards Preview

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Flashcards in Topic 4- Chemical Changes Deck (22):
1

What is a ph scale?

It measures of how acidic or alkaline a solution is.

The pH of an acid or alkali is a measure of the concentration of H+ ions in the solution.

2

What is a indicator?

It is a dye that changes colour depending in whether it's above or below a certain Ph.

3

What is an acid?

A acid is a substance that forms aqueous solutions with an Ph of less than 7, acid forms H+ ions in water.

4

What is a base?

A base is a substance with a pH greater than 7.

5

What is an alkali?

It is a base that dissolves in water to form a solution with a pH greater than 7. Alkalis forms OH- ions in water.

6

What is a reaction between acid and bases called?

Neutralisation

H+ + OH- = H2O

7

How can you calculate the concentration of acids or alkali?

Titration

8

What do acids produce in water?

Protons

9

What do strong acids do in water?

They completely ionise in water, all acid particles dissociate to release H+ ions.

Positions of equilibrium:
HCI->H+ + Cl-

10

What do weak acids do in solution?

They do not fully ionise in solution. Only a small proportion of acid particles dissociate to release H+ ions.

Position of Equilibrium:
CH3COOH<=> H+ + CH3COO-

11

What do concentration measure?

It measures how much acid there is in a certain volume of a water.

12

What are examples of base?

Metal Oxides & Metal Hydroxides& Metal Carbonates

13

Acid + Metal Oxide

Salt + Water

14

Acid + Metal Hydroxide

Salt + Water

15

Acid + Metal Carbonates

Salt + Water + Carbon Dioxide

16

The order of the reactive series:

Potassium
Sodium
Lithium
Calcium
Magnesium
Carbon
Zinc
Iron
Hydrogen
Copper

17

Acid + Metal

Salt + Hydrogen

18

Metal + Water

Metal Hydroxide + Hydrogen

19

Gain of Oxygen

Oxidation

20

Loss of Oxygen

Reduction

21

Ηow would metals above Carbon would be extracted?

Electrolysis

22

How would metals below carbon would be extracted?

By reduction using carbon.