Acids Bases and Salts

Question 1

What are

alkalis?

Answer 1

soluble bases

Question 2

What do you call substances which are both acids and bases?

Answer 2

amphoteric/amphiprotic

Question 3

How do acids react in solution?

Answer 3

they release hydrogen ions

(H+)

Question 4

How do alkalis act in solution?

Answer 4

they release hydroxide ions

(OH-)

Question 5

What are acids and bases in terms of protons?

Answer 5

acids - proton ‘donors’
bases - proton ‘acceptors’

Question 6

What is always formed when an acid and alkali react?

Answer 6

water

( H+ + OH- > H2O)

Question 7

What are

strong acids?

Answer 7

acids which completely dissociate in water

so the acid is completely reacted by the end of the reaction

Question 8

What are

weak acids?

Answer 8

acids which, when reacted, not all of the acid reacts and some of it remains as the original acid

Question 9

What are some examples of

strong acids?

Answer 9

hydrochloric acid (HCl)
nitric acid (HNO3)
sulfuric acid (H2SO4)

Question 10

What are some examples of

weak acids?

Answer 10

ethanoic acid (CH3COOH)

Question 11

What are the two general examples of bases?

Answer 11

metal oxide, metal hydroxide

Question 12

What products are formed when a metal and an acid are reacted?

Answer 12

salt + hydrogen

(MASH, metal + acid -> salt + hydrogen)

Question 13

What products are formed when a base and an acid are reacted together?

Answer 13

water + salt

(BAWS, base + acid -> water + salt)

Question 14

What products are formed when a metal carbonate and an acid are reacted?

Answer 14

water + carbon dioxide + salt

(CAWCS, metal carbonate + acid -> water + carbon dioxide + salt)

Question 15

What type of salt does hydrochloric acid form?

Answer 15

metal chloride

Question 16

What type of salt does sulfuric acid form?

Answer 16

metal sulfate

Question 17

What type of salt does nitric acid form?

Answer 17

metal nitrate

Question 18

What type of salt does ethanoic acid form?

Answer 18

metal ethanoate

Question 19

Define

salt.

(chemistry definition)

Answer 19

the chemical compound that results when cations and anions form an ionic bond

Question 20

What universal indicator colour would a pH range of < 2 produce?

Answer 20

red

Question 21

What universal indicator colour would a pH range of 2 - 4 produce?

Answer 21

orange

Question 22

What universal indicator colour would a pH range of 4 - 6 produce?

Answer 22

yellow

Question 23

What universal indicator colour would a pH range of 7 produce?

Answer 23

green

Question 24

What universal indicator colour would a pH range of 8 - 11 produce?

Answer 24

blue

Question 25

What universal indicator colour would a pH range of > 12 produce?

Answer 25

purple

Question 26

What is a more precise way of measuring pH than universal indicator?

Answer 26

a pH meter

Question 27

What are the soluble salts?

Answer 27

- containing Sodium - containing Nitrate - containing Ammonium - containing Potassium - containing Ethanoate - group I salts - group VII salts (except silver and lead) - containing sulfate (except lead and barium)

Question 28

What are the insoluble salts?

Answer 28

- containing anions (except SNAPE) - containing hydroxide (except SNAPE and barium)

Question 29

# How do you make soluble salts?

Answer 29

1. **React the metal**, metal oxide or metal carbonate **with the acid** until all of the acid has reacted (use an **excess** of metal and **heat**). 2. **Filter** the mixture to **remove the excess** solid metal, metal oxide or metal carbonate that remains. 3. **Concentrate** the **filtrate** by heating the solution. 4. Allow the solution to **cool** and **crystals** to **form**.

Question 30

# How do you perform an acid-alkali titration?

Answer 30

1. **Measure** out the **volume** of the first solution and place into a **conical flask**. 2. Add **2** drops of **indicator** to the conical flask. 3. **Measure** the **inital value** on the **burette** and record in the results table. 4. Add the second solution until the indicator **changes colour**. Add in drops toward the end point. **Measure** the **volume** on the **burette** and record in the results table. 5. Once you have **concordent results**, **repeat** the experiment **without indicator**. 6. **Evaporate** the water to leave your salt **crystals**.

Question 31

# Define concordent results. | (for a titration)

Answer 31

two (or more) readings within 0.20cm3

Question 32

# What is the basic method of making insoluble salts?

Answer 32

1. **Choose** two solutions of **soluble** salts. 2. **React** them together to form an **insoluble** salt. 3. **Filter** the mixture to **separate** the insoluble salt. 4. **Rinse** the solid with **distilled water**. 5. Allow to dry.