C5 Flashcards
In the table of ions what os the forst column
+1
Simple ions( group 1 ): Na+, Li+, K+, H+
Polyatomic ions: NH4+ ( ammonium )
Innthe table of ions what is in column 2
+2
Simple ions: Mg2+, Ca2+, Cu2+, Zn2+
In the table of ions what is in column 3
3+
Simple ions: Al3+
In the table of ions what is in collumn 4
1- Simple ions ( group 7 ): Cl-, Br-, I-
Polyatomic: NO3- ( nitrate )
In the table of ions what is in collumn 5
2-
Simple ions: O2-
Polyatomic: SO4 2- ( sulphate ), CO3 2- (carbonate )
What has happened to the metals in many of these ores?
They have been chemically bonded to other elements in compounds. Many have been oxidised to form their oxides.
Give an example of oxidation..
Iron + oxygen -> iron (III) oxide
What must you do to extract metals from their oxide form?
You must reduce them (oxygen is removed).
What is the reactivity series?
This is a list of metals in order of their reactivity, the most reactive are at the top and least reactive are at the bottom.
What can you use to help find the reactivity of metals?
Water or dilute acid
What happens when you react the metals with water?
The most reactive will give off a slight fizz, then a slow reaction, slight reaction with steam and finally the least reactive won’t react with water
How to find which metals are most reactive with dilute acid?
Most reactive: Explosion Fizz, giving of Hydrogen gas + salt React slowly No reaction - least reactive
How can you find if hydrogen gas is given of from an equation?
You can use the squeaky pop test with a lighted splint
What are Ores?
These are rocks from which you can extract the metals found in the periodic table from.
What happens in a displacement reaction?
A more reactive metal will displace a less reactive metal from its aqueous solution
When would nothing happen in a displacement reaction?
When the more reactive metal is already in solution
What can copper and hydrogen be used for in displacement reactions?
They can be used for seeing what metals are more and less reactive than them for the reactivity series
What does OILRIG mean?
Oxidation is loss (of electrons), reduction is gain (of electrons)
What is an ionic equation?
This is only showing the atoms that gained or lost electrons with another reactant
What is a half equation?
This is where you only show what happened in terms of electrons to each reactant
Why do we extract metal from ores?
Because there’s enough metal inside to make it economic to do so.
Why is gold and some other metals found in its native state?
Because it is so unreactive it didn’t even react with anything to make the ore.
How does carbon help extract metal from ores?
Anything less reactive than carbon can be extracted through a displacement reaction with it.
How are metals more reactive than carbon extracted?
Electrolysis (we don’t need to know this yet)
What is a metal + acid turn into?
Metal + acid -> salt + hydrogen
What salts are formed from HCl?
Chloride salts (Cl-)
What salts are formed from H2SO4?
Sulphates (SO4 ^2- ions)
What salts are formed from Nitric acid (HNO3)?
Nitrates (NO3 ^- ions)
Metal + water =
Metal hydroxide + hydrogen
Metal + oxygen =
Metal + oxygen = metal oxide ( if reactive enough )
Metal + acid
Metal + acid = salt + hydrogen ( if reactive enough )
Metal + water
Metal + water = metal hydroxide + hydrogen ( if reactive enough )
Metal oxide + acid
Metal oxide + acid = salt + water
Metal hydroxide + acid
Metal hydrixide + acid = salt + water
Metal carbonate + acid
Metal carbonate + acid = salt + water + carbonate
Ammonia + acid
Ammonia + acid = ammonium salt
Base + acid
Base + acid = salt + water
Alkali + acid
Alkali + acid = salt + water
How is an alkali different to a base
An alkali is a base that is soluble in water
What is a base
A base is a metal that neutralises acid to form salt and water
What colour of universal indicator is strong acid
Red ( 0 - 1)
What colour of universal indicator is strong alkali
Purple ( 13 - 14)
What is the definition of an acid
A substance that produces H+ ( aq) ( hydrogen ) ions when added to water
What do alkalis prodice when you add them to water
They produce OH- ( aq) ions ( hydroxide ) when added to water
What is the chemical equation for what happens to HCl ( hydrochloric ackd )when it is added to water
HCl ( g)= H+ ( aq ) + Cl- ( aq )
What is the chemical equation for what happens to sodium hydroxide when it is added to water
NaOH ( s) = Na+ ( aq ) + OH- ( aq )
What do strong acids do when they are added to water
They ionise COMPLETELY e.g HCl ( g)= H+ ( aq ) + Cl- ( aq ) - all ions have been spit up, reaction is not reversible
What do weak acids do when they are added to water
They only ionise PARTIALLY e.g CH3COOH = CH3COO- ( aq) + H+(aq) - only the hydrogen acid has ionised, the reaction can be reversible ( arrows going both ways )
What can pH stand for
Power of hydrogen, this relates that the more acidic the substance is, the more powerul hydrogen is in the compound
What happens when the concentration of the H+ ion is reduced by a factor of 10
The pH value goes up a unit ( indicating is has got less acidic )
Recite the chart of how the pH value changes with the concentration of hydrogen
Concentration of H+ ions ( mol/dm^3): 1x10^-1 : 1 - pH value 1x10^-2 : 2 - pH value 1x10^-3 : 3 - pH value 1x10^-4 : 4 - pH value etc
What is the rule for H+ ions and the change in pH
As the concentration of H+ ions decreases, the pH value increases ( get less acidic )
One way to remember reactivity series
Peggy: potassium Sue: sodium Cooks: calcium Meat: magnesium At: aluminium Cool: carbon Zoos: zinc In: iron Tropical: tin London: lead Hence: hydrogen Causing: copper Severe: silver Gut: gold Pain: platinum
C5 required practical method: making a copper salt
1) measuring cylinder, measure 20cm^3 or acid into beaker
2) stand beaker on tripod and gauze and warm gently until almost boiling, turn off Bunsen burner
3) add half spatula of copper(II) oxide powder into acid and stir using glass rod
4) continue adding copper oxide until no more dissolves. When copper oxide disappears the solution is clear blue
5) allow apparatus to cool completely and then filter mixture and discard residue
6) pour filtrate into evaporating basin and use water bath ( 250 cm^3 beaker with boiling water ) in tripod and gauze. Stop heating when crystals start to form
