Chemistry Topic 4// Acids Bases/ Titrations/ Strong, Weak Acids/ Reactivity series/ Redox/ Electrolysis

Question 1

Define pH scale

Answer 1

A measure of how acidic or alkaline a solution is

Question 2

What is an indicator used for

Answer 2

A dye that changes colour depending on whether its above or below a certain pH.

Question 3

What is a wide range indicator

Answer 3

contains a mixture of dyes that gradually change colour over a broad range of pH

Question 4

Define acids

Answer 4

Substance that forms aqueous solution with pH less than 7 and forms H+ ions in water

Question 5

Define alkalis

Answer 5

Base that dissolves in water to form solution with pH more than 7 and forms OH- ions in water

Question 6

What is the word equation of neutralisation

Answer 6

acid + base = salt + water

Question 7

What does titration allow you to find

Answer 7

allows you to find out exactly what volume of acid is needed to neutralise a measured volume of alkali and then measure concentration of acid or alkalis

Question 8

What is a universal indicator

Answer 8

Made from a mixture of different indicators used to estimate pH of a solution because it can turn a variety of colours

Question 9

What is the best indicator to use for titration and why

Answer 9

Single indicator for sudden colour change

Question 10

Define strong acids and weak acids

Answer 10

Strong acid - Fully ionise in water
Weak acid - Do not fully ionise in water and is a reversible reaction

Question 11

what do Acid and metal oxides form

Answer 11

Acid + Metal Oxide =
Salt + water

Question 12

What does Acid and Metal Hydroxides form

Answer 12

Acid + Metal Hydroxide =
Salt + WaterW

Question 13

What does Acid and Metal carbonate form

Answer 13

Acid + Metal carbonate = sat + water + carbon dioxide

Question 14

List elements in reactivity series

Answer 14

Potassium
sodium
Lithium
Calcium
Magnesium
Carbon
Zinc
Iron
Hydrogen
Copper

Question 15

What does Acid and metals form

Answer 15

Acid + Metal = Salt + Hydrogen

Question 16

What does Metal and Water form

Answer 16

Metal Hydroxide + Hydrogen

Question 17

What is Oxidation

Answer 17

Gaining of oxygen and Loss of electrons

Question 18

What is Reduction

Answer 18

Loss of oxygen and Gain of electrons

Question 19

Explain how metals above and below carbon in reactivity series can be extracted from ore

Answer 19

Metals above carbon can be extracted from electrolysis which is expensive because reactive metals are rare to find
Metals below carbon in reactivity series can be extracted by reduction using carbon so there is a loss of oxygen and carbon is oxidised