Acids and bases Flashcards
Neutral salt:
A neutral salt is a compound formed from the neutralization reaction between an acid and a base, where the resulting solution is neither acidic nor basic.
Definition of amphoteric oxides:
An amphoteric compound can react both as an acid and as a base. These compounds can either donate or accept protons (H⁺), or they can react with both acids and bases.
Acid
An acid is a substance that dissociates in water to produce H+ (aq) ions (or H3O+) as the only positive ions
H3O+
In aqueous solution, H+ ions bond to water molecues to form H3O+ ions, called hydronium ions.
when will acids show their properties
When dissolved in water`
Basicity
Number of ionisable hydrogen ions produced by a molecue of the acid
Concentration of acids
amount of acid dissolved per unit volume of water
Properties of acids
Sour taste
dissolve in water
turn blue litmus paper red
react with reactive metals
all acids are good conductors of electricty
able to change the colour of indicators
Non-reactive metals
Copper, silver, gold and platinum
Uses of sulfuric acid
making detergents, fertilisers and car batteries
Uses of hydrochloric acid
In leather processing and cleaning materials
Base
A substance that dissociates in water to produce OH- ions
Properties of alkalis
Alkalis have a bitter taste and soapy feel
They turn red litmus paper blue
They produce hydroxide ions when dissolved in water
all alkalis are good conductors of electricty
able to change the colour of indicators
When alkalis react with acids
They go through neutralisation and form salt and water only
Uses of ammonia solution
Window cleaning solutions and fertilisers
Uses of calcium oxide
In neutralising acidic soil
To make iron, concrete and sement
Uses of magnesium hydroxide
in toothpaste to neutralise acid on the teeth
In antacids to relieve gastric problems and indigestion
Uses of sodium hydroxide
Making soap and detergents
Industrial-cleaning detergents
Universal indicator
Acidic: Red
Neutral: Green
Alkaline: Purple
Methyl orange
Acidic: Red
Neutral: Orange
Alkaline: Yellow
Phenolphthalein
Acidic: Colourless
Neutral: Pale Pink
Alkaline: Pink
Examples of acidic oxide
oxides of non-metal, dissolve in water to form an acid
CO2
SO2 (Sulfur dioxide)
SO3 (Sulfur trioxide)
P4O10 (Phosphorus pentoxide
)
Properties of basic oxide
oxides of metals
most are insoluble in water, except for sodium oxide, potassium oxide (alkalis)
Solid at room temperature
Examples of amphoteric oxides
metallic oxides that react with both acids and bases to form salts and water
Al2O3
PbO
ZnO
Examples of neutral oxide
neither basic nor acidic and insoluble in water
H2O
CO (carbon monoxide)
NO (nitric oxide)
Arrhenius bases
NaOH
KOH
Ca(OH)2
NH3
Na2CO3
soluble salts
All nitrates are soluble
All halides (Cl-, Br- and I-) are soluble except Ag+ and Pb2+
All sulfates are soluble except Pb2+, Ba2+ and Ca2+
All sodium, potassium and ammonium salts are soluble
insoluble salts
All carbonates are insoluble except for Na+,K+ and NH4+
All oxides are insoluble except Na+ and K+
All hydroxides are insoluble except Na+ and K+. Ba2+ and Ca2+ are sparingly soluble
A white solid is seen around the stopper of a bottle containing sodium hydroxide solution. Which substance has reacted with sodium hydroxide to form the solid?
Carbon dioxide in the air (the solid is sodium carbonate)
metals below hydrogen in the reactivity series
Cu, Ag, Au(gold), pt (platinum), they will be extracted from their oxide
metals below carbon
Zn,Fe,Sn(tin),Pb
