Acids

Question 1

What state are Metal Carbonates normally?

Answer 1

Solid

Question 2

What are three soluble metal carbonates?

Answer 2

-Na2CO3
-K2CO3
-(NH4)2CO3
(all aq)

Question 3

What is an acid?

Answer 3

Acids release H+ ions in aqueous solution so they are defined as a proton (H+) donor

Question 4

What do alkalis release in an aqueous solution?

Answer 4

OH-

Question 5

What element do all acids contain?

Answer 5

Hydrogen

Question 6

What are the important acids?

Answer 6

-HCl
-HNO3 (nitric)
-H2SO4 (sulphuric)
-CH3COOH (ethanoic acid)

Question 7

What are 2 common alkalis?

Answer 7

NH3
Metal hydroxides and carbonates

Question 8

What are strong acids?

Answer 8

-Proton donors that completely dissociate in aqueous solution
(HCl)

Question 9

What are weak acids?

Answer 9

Proton donors that partially dissociate in aqueous solution (giving and equilibrium mixture)

Question 10

What happens when you put weak acids in solution?

Answer 10

-Only a small percentage of the acid molecules dissociate

Question 11

What are examples of strong acids?

Answer 11

-HCl
-H2SO4
-HNO3

Question 12

What is a base?

Answer 12

-Bases neutralise acids to form salts
-Defined as a proton acceptor

Question 13

What are examples of bases?

Answer 13

-Metal Hydroxides- Mg(OH)2
-Metal Carbonates- Na2CO3
-NH3

Question 14

Why is CuO a base?

Answer 14

It is insoluble in water

Question 15

What is an alkali?

Answer 15

A base that dissolve in water releasing hydroxide ions

Question 16

Why is ammonia is classed as an alkali?

Answer 16

When it is added or water, ammonium ion and hydroxide ions are formed

Question 17

What are the most common alkalis?

Answer 17

-NaOH
-KOH
-NH3

Question 18

What are all group 1 metal hydroxides?

Answer 18

Soluble in water and can form alkalis

Question 19

What is neutralisation?

Answer 19

When an acid reacts with a base to form a salt and water

Question 20

What happens during a neutralisation reaction?

Answer 20

The H+ ions from the acid are replaced by metal ammonium ions

Question 21

What does an acid + alkali and an acid + metal oxide make?

Answer 21

Salt + water

Question 22

What does an acid + (metal) carbonate make?

Answer 22

Salt + water + carbon dioxide

Question 23

What does an acid + ammonia make?

Answer 23

Ammonium salt

Question 24

What does a metal + acid make?

Answer 24

salt + hydrogen

Question 25

Why will there be effervescence when an acid + (metal) carbonate react?

Answer 25

CO2 has evolved and the solid CO2 will dissolve

Question 26

What are the observations for the acid base reactions: -acid + solid carbonate -acid + solid metal oxide -acid + reactive metal

Answer 26

-Fizzing -Solid disappears -Colourless solution forms

Question 27

what are the observations for the acid base reactions: -acid + aqueous carbonate -acid+ aqueous metal hydroxide

Answer 27

-No fizzing -No solid disappears (N/A) -Colourless Solution forms

Question 28

What can titrations be used to do?

Answer 28

-Find conc of a solution -Identify unknown compounds -Determine percentage purity

Question 29

What are standard solutions?

Answer 29

Solutions is known concentrations

Question 30

What can we do in a titration?

Answer 30

accurately measure the volume of one solution that reacts exactly with another solution

Question 31

How do you prepare a 250cm3 standard solution? (starting from a solid)

Answer 31

-weigh by diff the mass of is acid into a beaker using a mass balance -add enough distilled water to beaker to dissolve the solid -transfer solution into a volumetric flask using a funnel -rinse and transfer any residue down beaker and funnel into the volumetric flask -Add distilled water up to the graduation line in the flask -As you approach the graduation line add the water drop-wise using a pipette and ensure the bottom on the meniscus lines up with exactly with the mark -Stopper the flask and mix by inversion

Question 32

What should the results of a tritiation be?

Answer 32

-Accurate -Repeatable

Question 33

When is the a titration technique used good/consistent?

Answer 33

If the results are concordant or close

Question 34

What happens if salt solutions are left to evaporate at room temp?

Answer 34

-The hydrated salts are formed

Question 35

What does a hydrated salt have?

Answer 35

-The metal ion, the counter ion and water of crystallisation

Question 36

How is a hydrated salt quantified?

Answer 36

by heating until the mass remains constant when solid is cooled

Question 37

What is an example of a hydrated salt?

Answer 37

hydrated copper (ii) sulfate

Question 38

What is the metal ion in hydrated copper (ii) sulfate?

Answer 38

Cu2+

Question 39

what is the counter ion in hydrated copper (ii) sulfate?

Answer 39

SO42-

Question 40

What is the formulae for hydrated copper (ii) sulfate?

Answer 40

CuSO4•5H2O

Question 41

What is an anhydrous salt?

Answer 41

-CuSO4

Question 42

What is the water of crystallisation?

Answer 42

5H2O

Question 43

What is the hydrated salt?

Answer 43

CuSO4•5H2O (blue)