Acids, Bases + Salts

Question 0

Reacting acids with metals

Answer 0

Metals above hydrogen (has to be more reactive to displace the hydrogen) in the Reactivity Series react with dilute acids to produce salts and hydrogen gas. The more reactive the metal, the more rigorous the reaction

Acid + Metal –> Salt + Hydrogen

Question 1

Reacting acids with alkalis and bases

Answer 1

Metal hydroxides and oxides react with acids to produce a salt and water. Soluble bases are called alkalis. This is known as a neutralisation reaction.

Acid + Alkali/Base –> Salt + Water

Question 2

Reacting acids with carbonates

Answer 2

Carbonates react with acids to produce carbon dioxide, a salt and water

Acid + Carbonate –> Salt + Carbon Dioxide + Water

Question 3

Naming salts

Answer 3

When naming a salt, the first part of the name comes from the metal ion present. The second part comes from the parent acid.

Question 4

Parent acids --> salts 
Hydrochloric
Sulphuric
Nitric
Phosphoric

Answer 4

Chlorides
Sulphates
Nitrates
Phosphates

Question 5

Solubility rules 
Nitrates
Sulphates
Chlorides
Hydroxides
Carbonates

Answer 5

Nitrates - all nitrates are soluble
Sulphates - all sulphates are soluble except lead and barium
Chlorides - all chlorides (and other halides) are soluble except lead and silver
Hydroxides - all hydroxides are insoluble except potassium, sodium and ammonium
Carbonates - all carbonates are insoluble except potassium, sodium and ammonium

Question 6

Insoluble hydrochloric compounds

Answer 6

Lead chloride

Silver chloride

Question 7

Insoluble sulphuric compounds

Answer 7

Barium sulphate
Lead sulphate
Calcium sulphate is only slightly soluble

Question 8

Insoluble carbonic compounds

Answer 8

Potassium carbonate
Sodium carbonate
Ammonia carbonate

Question 9

Insoluble hydroxide compounds

Answer 9

Potassium hydroxide
Sodium hydroxide
Ammonia hyrdoxide

Question 10

State symbol and when to use a solid

Answer 10

S

Insoluble salts

Question 11

State symbol and when to use liquid

Answer 11

L

Usually water

Question 12

State symbol and when to use gas

Answer 12

H

H2 CO2 O2

Question 13

State symbol and when to use aqueous (dissolved in water)

Answer 13

Aq

When starting with an aqueous solution (acids, alkalis), if a soluble salt is produced, it will be dissolved in water

Question 14

How to write a chemical equation

Answer 14

1) write a word equation (or if confident go straight to symbol equation)
2) write the symbol equation using the rules for writing formulae
3) balance your symbol equation
4) consider the state of each substance and put it after the formula in brackets

Question 15

Formulae for acids:
Hydrochloric
Sulphuric
Phosphoric
Nitric

Answer 15

H = HCl
S = H2SO4
P = H3PO4
N = HNO3

Question 16

Remember:

• acids and alkalis (soluble metal oxides/hydroxides) are …
• if a soluble salt is produced it will be …
• if an insoluble salt is produced it will be …
• carbonates, bases and metals are …
• oxides are always …

Answer 16

Aqueous 
Aqueous
Solid
Solids
Solid

Question 17

Why are acid base/alkali reactions called neutralisation reactions?

Answer 17

When oxide ions combine with hydrogen ions water is made. The presence of hydrogen ions is what makes acid, acidic, removing the hydrogen ions, the acid has been neutralised (mix of high and low phs)

Question 18

Define an acid

Answer 18

An acid is a proton (hydrogen ion) donor

Question 19

What do acids contain to make them acidic

Answer 19

Hydrogen ions

Question 20

Define a base

Answer 20

A base is a proton (hydrogen ion) accepter

Question 21

What do bases/alkalis contain to make them alkali

Answer 21

Hydroxide ions

Question 22

Equation to show the production of water when an acid and base react

Answer 22

H+ (aq) + OH- (aq) –> H2O (l)

Question 24

More OH =

More H =

Answer 24

Alkaline

Acidic

Question 25

Ionic charges for group 1,2,3,(5),6,7

Answer 25

+1,+2,+3,-3,-2,-1

Question 26

Ionic charges for ammonium, nitrate, hydroxide, hydrogencarbonate, carbonate, sulphate

Answer 26

NH4 +, NO3 -, OH -, HCO3 -, CO3 2-, SO4 2-

Question 27

what happens when a magnesium ribbon is put into sulphuric/hydrochloric acid

Answer 27

fizzes, magnesium dissolves, exothermic reaction

Question 28

what happens when a magnesium ribbon is put into sulphuric/hydrochloric acid, test tube held over to collect gas, then a lighted splint put near the top of the tube

Answer 28

hydrogen is present thus makes a squeaky load pop, however sulphuric acid produces more hydrogen

Question 29

what happens when copper turnings are put into a tube of sulphuric acid

Answer 29

nothing as its below hydrogen in the reactivity series

Question 30

investigate the reaction of copper oxide with sulphuric acid

Answer 30

- copper oxide reacts with the acid and buzzes turning blue, once more has been added and all reacted with the acid, it goes black and stays black - it is then filtered to remove copper oxide residue - the filtrate is copper sulphate and water - the residue is excess copper oxide

Question 31

investigate the reaction of calcium carbonate with sulphuric acid

Answer 31

- the mixture fizzes and bubbles up, becoming cloudy, this then slows down and becomes clear again - this reaction stops occurring when the acid becomes saturated - the filtrate is calcium chloride and water - the residue is excess calcium carbonate - when left to dry the water will evaporate and form crystals of calcium chloride

Question 32

blue litmus paper turns

Answer 32

red when an acid is present

Question 33

red litmus paper turns

Answer 33

blue when a base is present

Question 34

methyl orange indicator turns

Answer 34

- yellow when an alkaline is present - orange when the substance is neutral - red when an acid is present

Question 35

phenolphthalein indicator turns

Answer 35

- pink when a base is present | - colourless when an acid is present

Question 36

method for making soluble salts

Answer 36

1) Add an excess of the solid reactant to the acid 2) Filter the mixture 3) Heat the mixture until it's warm 4) Leave in a cool dry place

Question 37

why not heat a mixture for making soluble salts until its dry

Answer 37

heating for dryness would produce an anhydrous salt

Question 38

when does the acid need to be heated when making soluble salts

Answer 38

if using any solid except magnesium/carbonate

Question 39

method for making sodium, potassium and ammonium salts

Answer 39

1) Add a measured volume of alkaline solution to a flask using a pipette (or measuring cylinder) 2) Add a named indicator 3) Add acid from a burette 4) Until a correctly stated colour change 5) Note the volume of acid added 6) Mix the same volumes of acid and alkaline solution without the indicator

Question 40

what is an insoluble salt

Answer 40

Need to mix together solution of soluble salts, the dissolved ions meet in solution to form a precipitate of the insoluble salt. The other ions are classes as spectator ions.

Question 41

How to write an ionic equation

Answer 41

1) Write out the word equation 2) Write out the symbol equation with state symbols and balancing 3) Identify ions that make insoluble salt, remove spectator ions from this 4) Write out ionic equation with state symbols, balancing and charges

Question 42

why can't we use an indicator to measure in an insoluble salt experiment

Answer 42

salts are neutral from the start to the end

Question 43

method for making insoluble salts

Answer 43

1) Insoluble salts can be made by mixing together two soluble salts 2) When a soluble salt dissolves, the ions separate from each other and move about between the water molecules 3) When two ions meet in the solution, they will just move apart again, unless in doing so, they are forming an insoluble salt. In this case they stay bonded and come out of solution as a precipitate 4) Salts are made up of a cation/positive ion ( a metal ion or the ammonium ion) and an anion/negative ion ( a non-metal ion) 5) To make an insoluble salt you need to choose two soluble salts that contain the desired positive and negative ions to form your insoluble salt 6) Remember that all nitrates are soluble and all potassium, ammonium and sodium salts are soluble