Chapter 10 and 11 - Acid bases salts Flashcards
Define acids
substance that produces hydrogen ions when dissolved in water
Examples of common acids
hydrochloric acid (HCl)
sulfuric acid (H2SO4)
nitric acid (HNO3)
Ethanoic acid (CH3COOH)
What is the only organic acid
Ethanoic acid (CH3COOH)
State three strong acids
= hydrochloric
- sulfuric
- nitric
State one weak acid
ethanoic acid
4 properties of acids
- sour
- has a Ph lesser than 7
- can conduct electricity in aqueous state
- turns blue litmus red
What are four things acids reacts with
metal , alkali , carbonate, basic oxide
What is the special product of reaction between acid and metal
hydrogen
What is the special product of reaction between acids and carbonate salt
carbon dioxide
Three uses of acids
rest removal , food preservation , manufacture fertilisers
Definition of alkali
substances that produces hydroxide ions, when dissolved in water
Define bases
oxides/hydroxides of metals usually insoluble
Relation between base and alkali
alkalis are soluble bases, because bases are normally not soluble
Common bases
not SPCA hydroxide, metal oxides
NOT :
sodium hydroxide
potassium hydroxide
calcium hydroxide
ammonium hydroxide
Common alkali
SPCA hydroxide
sodium hydroxide
potassium hydroxide
calcium hydroxide
ammonium hydroxide
5 properties of alkalis
- bitter taste
- soapy feel
- Ph greater than 7
- turns red litmus paper blue
- can conduct electricity in aqueous state
What is the special product of the reaction between alkali and ammonium salt
ammonia
3 uses of alkalis
dissolve grease, medication for gastric pains , manufacture toothpaste
Definition of neutralisation
reaction where acid reacts with base to form salt and water
ionic equation for neutralisation reaction
H+(aq) + OH-(aq) = H2O(l)
What proofs a neutralisation reaction
water being produced
What type of energy reaction is neutralisation
exothermic
How neutralise a highly acidic soil
add CaO or Ca(OH)2
- calcium oxide (lime)
- calcium hydroxide (slaked lime )
How to neutralise a slightly acidic soil
add CaCO3
calcium carbonate / limestone
When there is too much hydrochloric acid in the stomach there is indigestion how to neutralise
add Mg(OH)2 or Na3CO3
magnesium hydroxide or sodium carbonate
What are 4 things that can be added to soil to neutralise
quicklime
slake lime
limestone
ammonium fertilisers
Can quicklime (CaO) be added in excess why
no because it is soluble in water and make the soil too alkaline
Can slaked lime be added in excess why
no because it is soluble in water and make the soil too alkaline
Can limestone be added in excess why
yes, it is insoluble in water so the excess powder can be seen whitely in the soil and does not affect the Ph of the soil
Can ammonium fertiliser be added with calcium hydroxide why
no if washed into the lakes it promotes algae growth and affects aquatic life
What PH scale causes a litmus paper to turn red
0-6
What PH scale turns the litmus paper blue
8-14
Colour of UI if ph is 1
red
Colour of IS if ph is 1-2
orange
Colour of UI if ph is 4-6
yellow
Colour of UI if ph is 7
green
Colour of UI if ph is 8-10
blue
Colour of UI If ph is between 11-12
indigo
Colour of UI if ph is 13-14
violet
Two neutral substances
water and sodium chloride
Definition of acidic oxides
- oxides of non metals so it is acidic
- reacts with bases to form salt and water
Definition of basic oxides
- oxides of metals so its alkaline
- reacts with acid to form salt and water
Definition of amphoteric oxides
- oxide thar has both alkaline and acidic properties
- reacts with acids or alkalis to form salt and water
Definition of neutral oxides
- oxides that are neither acidic not alkaline properties, so they are neutral
- does not react with acids or alkalis
What two types of oxides are metal oxides
amphoteric oxide and basic oxides
What two types of oxides are non metal oxides
neutral and acidic oxides
Which type of metal oxide contains more oxides
basic oxides
What are the three special metal oxides and what group are they
ZAP - zinc oxide, aluminium oxide and lead oxide (Pb) an they are from amphoteric oxides
Which type of non metal oxide contains most of the oxides
acidic oxides
Which type of non metal oxide contains most of the oxides
acidic oxides
What are the three differing non metal oxides and what group do they belong to
CHiNA - carbon monoxide water and nitrogen monoxide and they belong to the neutral oxides
If the salt Is insoluble what type of preparation method should I use
precipitation method
If the salt is soluble what type of reaction method should I use
acid reaction or titration
What are the special needs of reactant in the precipitation methods
Two soluble salts must be used and after double displacement it must give the salt required in the question. The order product should be soluble - just for checking
What’s are two tips for the titration method
Use SPAN
-sodium slats
- potassium salts
- ammonium salts
- metal nitrate salt (any metals)
What are the special requirements for titration method
The reactant must be aqueous and must form a aqueous version of what is asked in the question
How many different acid reactions are there
4
What two reactions is better to use for acids reactions
where the other reactant is a hydroxide or carbonate
For a reaction between sodium sulfate and barium nitrate to form barium surface and sodium nitrate what is the method and what are teh 5 steps to prepare it
PPT METHOD
- add excess sodium sulfate to barium nitrate in a beaker
-Stir until no more PPT is formed
- filter mixture to collect PPT
- was residue with cold distilled water to remove impurities
- press crystals between sheets of filter paper to dry
For a reaction between sulphuric acid and copper oxide to form copper sulfate and water what is the method used and exalting the 7 steps to do it
ACID REACTIONS METHOD
- add copper 2 oxide to sulfuric acid in a beaker
- stir to dissolve copper 2 oxide
- continue to add more copper 2 oxide and stir until no more copper 2 oxide can dissolve
- filter off excess copper 2 oxide
- heat filtrate to saturation
- allow to cool and crystals of copper 2 sulfate will form
- press crystals between sheets of filter paper to dry
Why is it not good to use reaction between acid and metal for doing acid reaction method
some metals do not react with acids like the least reactive ones (reactivity series )
For a reaction between sulphuric acid and sodium hydroxide to form sodium sulfate and water what is the method used and explain the 8 steps .
TITRATION METHOD
- pipette 25.0 cm3 of sodium hydroxide into conical flask
- add a few drops of indicator into the flask
- add drop wise of sulfuric acid from beretta into flask
- when there is a colour change of indicator firstly observed, note volume of sulfuric acid used
-repeat experiment with exact volume of sodium hydroxide and sulfuric acid without adding indicator
- heat solution formed to saturation
- allow to cool and crystals of sodium sulfate will form
- press crystals between sheets of filter paper to dry
Define acid
Substance that produces hydrogen ions when dissolved in water
State the ion that causes acidity
Hydrogen ions (H+)
Name the properties of acids
Sour taste
Ph lesser than 7
Turns blur litmus red
Can conduct electricity in aqueous state
Why is aqueous HCL acidic
When HCL dissolves In water ionisation occurs and HCL ionises into H+ ions and Cl- ions plus water ionises into H+ and OH- ions therefore more H+ ions more acidic
Why is dry HCL gas Nutrel
HCL is covalently bonded so electrons are shared between molecules so no ionisation so no H+ ions or OH- ions so it’s not acidic or alkaline or neutral
How to test between two acids and determine the stronger one
Add equal mass of Zn (same mass and concentration ) and measure the amount of gas produced in the first minute, the acid that produced more hydrogen gas is the more powerful acid
State the ion that causes alkalinity
OH-
Name properties of bases
Butter taste
Soapy feel
Ph higher than 7
Turns red litmus blue
Can conduct electricity in aqueous state
What is the ionic equation for neutralisation
H+ (aq) + OH- (ap) = H2O (l)
Why is calcium hydroxide added to soil
To neutralise acidity in soil that it caused by acid rain so that crops can grow better
Why does most bread dough containing baking powder rise when heated
Acidic baking powder ionises when in contact with moisture to form H+ ions
H+ ions then reacts with sodium hydrocarbonate to produce CO2
CO2 causes Bread to rise when heated
How to determine the end point of titration
Neutralisation is an endothermic process so can use max temperature recorded to determine end point
Why does electrical conductivity decrease when neutralisation is taking place
Good electrical conductivity depends on no of ions during neutralisation the H+ ions and OH - ions are lesser so regions available to conduct electricity is lesser so electrical conductivity is lesser
How can aluminium oxide be removed
Using
- acid
- alkaline
- sandpaper
Why are group 4 and 5 oxides are less effective I’d neutralising acid
They are non metals that usually form acidic oxides and they cannot neutralise acidity
What is the UI colour when sodium oxide is add ( metal oxide )
Oxides of sodium dissolve on water to form alkaline solution therefore it turns the universal indicator violet
What is the UI colour when oxides of sulfur are added (non metal oxide )
Oxides of sulfur dissolve in water to form acidic solution therefore turns universal indicator red.
How to know when to use titration method
When the salt to be prepared if SPA or group 1 - sodium potassium and ammonium
How to know when to use acids reaction method
When the salt to be prepared is not SPA or group 1 - sodium potassium and ammonium
Tips to chose reactants in titration
SPA some girl
Some guy N
Tips to choose reactants in titration
- use acid or alkaline
- choose carbonate salt
Tips to chose reactants for scuds reaction method
- Acid plus base ( not SPCA - OH)
OR - acid plus carbide salt
