Bonding, acids, bases and salts Flashcards
What are ions?
charged particles
How are ions formed?
when atoms loose or gain electrons
What are negative ions called?
anions
What are positive ions called?
cations
How do positive ions form?
when atoms lose electrons
how do negative ions form?
when atoms gain electrons
What is ionic bonding between?
a metal and non - metal
Describe the attraction in ionic bonding?
oppositely charged ions are strongly attracted to each other by electrostatic attractions
What are ionic compounds?
made up of a positively charged part and a negatively charged part
What is the overall charge of an ionic compound?
zero
What type of drawing can be used to illustrate ionic compounds?
dot and cross
What do compounds with ionic bonding always have?
giant ionic structures
Describe the arrangement of ionic structures?
closely packed 3D lattice arrangement
What is the attraction in an ionic structure?
electrostatic attraction between oppositely charged ions is very strong
What are the physical qualities of ionic compounds?
high melting + high boiling points, not electrical conductors in solid state but if melt or dissolve in water they can conduct
What is a covalent bond?
a shared pair of electrons
What is the attraction in a covalent bond?
electrostatic attraction between the negatively charged shared electrons and the positively charged nuclei of the atoms involved
Explain simple molecular substances?
- strong covalent bonds
- weak intermolecular forces of attraction
- low melting and boiling points
- gas and liquid at room temp
Explain melting + boiling points in simple molecular substances?
- melt + boil points increase as relative molecular mass increases due to increase strength in forces
How are giant covalent structures bonded to each other?
strong covalent bonds
Melt + boil points of giant covalent structures?
very high melt + boil points
What are diamond and graphite made of?
carbon atoms
Do giant covalent conduct electricity?
no
Are giant covalent structures soluble in water?
no - insoluble
Explain the qualities of diamond?
- network of carbon atoms that each form 4 covalent bonds
- high melting points, strong bonds
- rigid lattice structure, very hard
- doesnt conduct electricity, no free electrons
Explain qualities of graphite?
- each carbon atom only forms three covalent bonds, creating layers of carbon atoms
- layers held together by weak intermolecular structures making it soft and slippery
- high melting point
- one delocalised electron that can move, non-metal which conducts electricity
What is C60 fullerene?
simple molecular substance
Explain C60 fullerene ?
- hollow sphere made of 60 carbon atoms
- made of large covalent molecules
- intermolecular forces which can slide over each other , soft material
- one delocalised electron that cant move between molecules, poor conductor of electricity
acid + metal =?
salt + hydrogen
How do you make a salt + hydrogen?
acid + metal
What is one way to fund out how reactive a metal is?
reaction of metal with dilute acid
the more reactive the metal…?
the faster the reaction will go
Describe a practical for the differences in reactivity of metals?
- set up three boiling tubes and fill with equal amounts of dilute hydrochloric acid/ sulfuric acid
- place pieces of zinc, magnesium, iron in separate test tubes
- speed of reaction indicated by rate of bubbles of hydrogen given off
- test for hydrogen, magnesium should give off most
metal + water =?
metal hydroxide + hydrogen
What will metals like magnesium zinc and iron react with?
steam
What won’t copper react with?
water or stream
Explain experiment for magnesium, zinc or iron with water?
- place mineral wool soaked in water at bottom of tube
- place test-tube on side and add metal further down
- heat wool to produce steam
- hydrogen given off
What does the PH scale go from?
0-14
What is a neutral substance on PH scale?
7
What is an acid on the PH scale?
0-6
What is an alkali on the PH scale?
8-14
what is an indicator?
a dye that changes colour depending on the PH
What are the 4 indicators?
litmus paper, universal indicator, phenolphthalein, methyl orange
Explain litmus paper?
- tests for acid or alkali,
- red for acid
- purple for nuetral
- blue in alkali
Explain phenolphthalein?
- colourless in acid
- pink in alkali
Explain methyl orange?
- red in acid
- yellow in alkali
What is an acid?
a source of hydrogen ions, they are protein donors that have a PH of less then 7
What is a base?
a substance that can neutralise an acid, they are proton accepts.
- alkalis are soluble bases
WHat is an alkali?
- source of hydroxide ions, pH greater then 7.
What is the reaction between an acid and base called?
neutralisation
neutralisation equation in terms oh hydrogen?
H + OH -> H20
What are the products ( type) formed in neutralisation?
nuetral
When do salts form?
when acid reacts with base
acid + base ->
salt + water
Acid + metal oxide ->
salt + water
acid + metal hydroxide = ?
salt + water
Acid + ammonia = ?
ammonium salt
acid + metal/ metal carbonate =?
salt
acid + metal carbonate =
salt + water + carbon dioxide
What are the two types of salts?
insoluble or soluble
If a percipitate is formed what is the salt?
insoluble
If a solution if formed what is the salt?
soluble
Name all soluble salts?
- sodium
- potassium
- ammonium
- chlorides ( not silver or lead)
- sulfates ( not lead barium and calcium)
Name all the insoluble salts?
- silver chloride
- lead chloride
- lead sulphate
- barium sulphate
- calcium sulphate
- carbonates ( not sodium potassium and ammonium)
hydroxides (not sodium, potassium and calcium)
Are sodium, potassium and ammonium soluble or insoluble?
soluble
Are nitrates soluble or insoluble?
soluble
Are common chlorides soluble or insoluble?
soluble
What common chlorides are insoluble?
silver chloride and lead
What common sulfates are insoluble?
lead, barium and calcium
Are sulfates insoluble or soluble?
soluble
Are carbonates soluble or insoluble?
insoluble
Which carbonates are soluble?
sodium, potassium and ammonium
are hydroxides soluble or insoluble?
insoluble
Which hydroxides are soluble?
sodium, potassium, calcium
How to you make a soluble salt (simple)?
reacting an acid that contains one of the ions you want in the salt with an insoluble base that contains other ion you want
Explain how to make a soluble salt?
- heat acid in water bath to speed reaction ( do in fume cupboard)
- add base to acid to produce soluble salt
- filter off the excess solid to get solution containing only salt + water
- heat solution slightly to evaporate some water
- leave to cool and allow salt to crystallise
- filter off solid salt and allow to dry