Unit 11 - acids, bases, and salts

Question 1

What is an acid

Answer 1

An acid is a molecule or ion capable of donating a proton( hydrogen ion). And gives salt and water for product when it react with bases

Question 2

Is the solution that has pH number of 7 an alkaline or acid

Answer 2

Neither, it’s neutral

Question 3

What kind of ion do all the acid contain

Answer 3

Hydrogen ion

Question 4

Difference between strong and weak acid

Answer 4

In solution of strong acids, all the molecules dissociate into ions. However, in solution of weak acids, only some molecules dissociate. Also, strong acid has higher concentration of hydrogen ions.

Question 5

‘Weak acid conduct electricity better than strong acid’

is this statement correct

Answer 5

no, strong acid has better conductivity.

Question 6

What kind of ion do all the alkaline contain

Answer 6

Solutions of alkalis contain hydroxide ions

Question 7

Ammonia solution has a pH of 11.1, sodium hydroxide has pH of 13 . Which alkali will show higher conductivity, and why

Answer 7

Sodium hydroxide, alkali with higher pH , contain more ions

Question 8

Give three typical acid reactions ( metals, bases, carbonates)

Answer 8

With metal- acid + metal gives salt + hydrogen
With bases- acid + bases gives salt + water
With carbonates- acid + carbonate gives salt + water + carbon dioxide

Question 9

What is neutralisation

Answer 9

A reaction between acid and base that they give water and salt

Question 10

Is neutralisation a redox reaction, give reasons

Answer 10

It’s not because no electrons are transferred.

Question 11

Is the reaction between metal and acid redox reaction, why

Answer 11

It is because electrons are transferred

Question 12

Why does neutralisation gives water as a product

Answer 12

Hydrogen ion in acid and hydroixde ion in base combine together to form water molecules

Question 13

Acids are proton ____, and bases are proton ____.

Answer 13

Donors, acceptors

Question 14

Explain how magnesium oxide neutralises HCl acid

Answer 14

The acid dontaes proton to the oxide ions, then it beomces water molecules. The magnesium ions join the chloride ions in solution.

Question 15

What are oxides

Answer 15

Compound that contains oxygen and another element

Question 16

Are metal oxide basic or acidic

Answer 16

basic

Question 17

Are non-metal oxide basic or acidic

Answer 17

acidic

Question 18

What is an amphoteric oxide

Answer 18

the oxide that will react with both acids and alkalis

Question 19

Do neutral oxides react with acid or bases

Answer 19

Neither of them

Question 20

Describe the process of making salt and obtaining it in a detail, starting with a metal

Answer 20

Add the metal to the dilute acid in a beaker. It starts to dissolve, bubbling( hydrogen) stops when all the acid is used up. Remove excess metal by filtering then heat the remaining solution until the solution is saturated. Leave this to cool. Then you will obtain crystals

Question 21

Describe the process of making salt and obtaining it in a detail, starting with an insoluble base

Answer 21

Add the base to dilute acid, add more until no more will dissolve. Remove the excess base by filtering. Heat the remaining solution until it is saturated then leave it to cool. Obtain the crystal.

Question 22

How the phenolphthalein works

Answer 22

It is an indicator that is pink in alkaline solution but colourless in neutral and acidic solution

Question 23

Describe the process of making salt and obtaining it in a detail, starting with bases

Answer 23

Put the basic solution into a flask and add two drops of phenolphthalein add the acid from a burette, little at a time. Swirl the flask carefully, to help the acid and alkali to mix. When the indicator turns colourless( when the alkali has all been used up), find how much acid you added. Then repeat the experiment without indicator, same volume of basic solution and acid. Heat the solution from the flask to evaporate some of water then leave it cool. Obtain the crystal.

Question 24

State soluble salts

Answer 24

All sodium, potassium, and ammonium salts
all nitrates
chloride except silver and lead chloride
sulfates except calcium, barium and lead sulfate.

Question 25

State insoluble salts

Answer 25

Silver and lead chloride
calcium, barium, and lead sulfate
all other carbonates except sodium ,potassium and ammonium carbonates

Question 26

What are spectator ions

Answer 26

The ions that do not take part in the reaction but present in the reaction

Question 27

Describe how to make insoluble salt by precipitation

Answer 27

To precipitate an insoluble salt, mix a solution that contains its positive ions with one that contains its negative ion.

Question 28

How methyl orange works

Answer 28

It is an indicator that is red in acidic solution and yellow in basic and neutral solution