Reactivity Series Flashcards
What is the trend in reactivity of the reactivity series?
As you go down, the reactivity decreases
What is the reactivity series in order?
Potassium
Sodium
Lithium
Calcium
Magnesium
Aluminium
Carbon
Zinc
Iron
Hydrogen
Copper
Silver
Gold
What gas is formed when reactive metals are added to dilute acids?
Hydrogen
How can you test for hydrogen gas?
Hold a lit splint in the gas and if hydrogen is present a squeaky pop will be heard
What is the chemical formula of hydrochloric acid?
HCl
What is the chemical formula of sulphuric acid?
H₂SO₄
How can one name salts produced from acids?
The first part of the name of the salt comes from the name of the metal.
The second part of the name of the salt comes from the acid used to make the salt
What is the chemical formula of nitric acid?
HNO₃
What would hydrochloric acid make when reacted with a metal?
Chloride
What would sulphuric acid make when reacted with a metal?
Sulphate
What would nitric acid make when reacted with a metal?
Nitrate
When conducting an experiment to determine the order of reactivity of a group of metals, what would the independent variable be?
Type of metal
When conducting an experiment to determine the order of reactivity of a group of metals, what would the dependent variable be?
Volume of hydrogen gas produced in a set variable for time or the temperature change (higher temp change results in more hydrogen gas produced)
When conducting an experiment to determine the order of reactivity of a group of metals, how could one measure the dependent variable?
By using a gas syringe (cm3) or a thermometer
When conducting an experiment to determine the order of reactivity of a group of metals, what would the control variables be?
Concentration of acid, volume of acid, mass of metal (g)
When conducting an experiment to determine the order of reactivity of a group of metals, what would the method be?
- Measure 20 cm3 of acid into the boiling tube
- Measure the temperature of the acid
- Add 5g of the metal powder
- Record the temperature and observations
Why doesn’t aluminium react with a dilute acid?
Aluminium has a protective oxide layer that prevents the acid from reaching the pure aluminium.
Why doesn’t copper react with a dilute acid?
Copper is too unreactive
What is a displacement reaction?
A reaction where a more reactive element replaces a less reactive element in a compound
What happens when magnesium metal is added to copper(II) sulfate solution?
Magnesium displaces copper; the blue solution turns colourless and reddish-brown copper forms
What happens when magnesium metal is added to zinc sulfate solution?
Magnesium displaces zinc; no colour change is seen
What happens when magnesium metal is added to iron(II) sulfate solution?
Magnesium displaces iron; the pale green solution fades and grey iron forms
What happens when zinc metal is added to copper(II) sulfate solution?
Zinc displaces copper; the blue solution turns colourless and reddish-brown copper forms
What happens when zinc metal is added to iron(II) sulfate solution?
Zinc displaces iron; the green solution fades and grey iron forms
What happens when zinc metal is added to magnesium sulfate solution?
No reaction occurs; zinc is less reactive than magnesium
What happens when iron metal is added to copper(II) sulfate solution?
Iron displaces copper; the blue solution turns green or colourless and reddish-brown copper forms
What happens when iron metal is added to zinc sulfate solution?
No reaction occurs; iron is less reactive than zinc
What happens when iron metal is added to magnesium sulfate solution?
No reaction occurs; iron is less reactive than magnesium
What happens when copper metal is added to magnesium sulfate, zinc sulfate or iron(II) sulfate?
No reaction occurs; copper is less reactive than all of them
Why is there no reaction between magnesium and magnesium sulphate?
Metals don’t displace each other
What is oxidation?
A reaction where oxygen is gained (electrons are lost)
What is reduction?
A reaction where oxygen is lost (electrons are gained)
What is a redox reaction?
A reaction where oxidation and reduction occur
What is observed when aluminium reacts with iron oxide?
A very bright light
Iron becomes molten
Lots of heat is given out
Large explosion
What is the name of the reaction where aluminium reacts with iron oxide?
The Thermite reaction
What is the thermite reaction used for?
Welding railway and tram tracks together
What is an exothermic reaction?
A reaction where heat is given out (surroundings gain thermal energy)
What is an endothermic reaction?
A reaction where heat is taken in (surroundings lose thermal energy)
Is the thermite reaction an endothermic or exothermic reaction?
Exothermic
Why is the thermite reaction a redox reaction?
The thermite reaction is a redox reaction because aluminium loses electrons (oxidation) and iron(III) oxide gains electrons (reduction)
What would happen is you heated iron metal with aluminium oxide
No reaction as aluminium is the more reactive metal and is already in a compound
A reducing agent causes another substance to be reduced. In the process what happens to it?
It is oxidised
An oxidising agent causes another substance to be oxidised. In the process what happens to it?
It is reduced
What is an ore?
A rock that contains a metal compound
What can be done to obtain a pure metal if the metal is more reactive than carbon
Electrolysis can be used
What happens to a nail in water?
Orange/brown rust forms.
What happens to a nail with a drying agent?
The water remains clear. No rust forms.
What happens to a nail in boiled water and oil?
The water remains clear. No rust forms. A layer disappears.
What happens to a nail wrapped in moist cotton?
The water remains clear. No rust forms. A layer disappears.
In an experiment to test for the presence of rust in iron, how would a drying agent affect rust?
Rust wouldn’t be present as the drying agent removes the water
In an experiment to test for the presence of rust in iron, how would boiled water and a top layer of oil affect rust?
No rust would be present as the boiled water doesn’t have oxygen and the oil would prevent oxygen from being re-dissolved into the water
When a more reactive metal is loosely wrapped around the iron, which will rust first?
The more reactive metal
What conditions are required for rusting?
Iron, water and oxygen
Why is rusting a problem?
It makes the iron brittle, so it is not durable
What methods can be used to prevent rusting?
Protection by physical barrier
Sacrificial protection
Galvanising
What is protection by physical barrier?
When something is applied to the iron to prevent oxygen and/or water accessing the iron
What substances can be used for protection by physical barrier?
Paint, oil, grease, plastic coating, tin planting or electroplanting
What is electroplanting?
Using electricity to place a thin coating of meal on the iron
What is an advantage of protection by physical barrier?
It is cheap
What is the main con of protection by a physical barrier?
If the coating isn’t maintained (e.g becomes scratched) the air and water will be able to get to the iron and cause rusting
What is sacrificial protection?
When a more reactive metal is loosely wrapped around the iron so that the metal corrodes and prevents the iron from rusting
What is an advantage of sacrificial protection?
It can be used on things like railways where a physical barrier would be scraped easily from the friction of the train
What is the main con of protection by sacrificial protection?
Over time the more reactive metal will be used up and if not replenished the iron will also rust
What is galvanising?
When iron gets a coating of zinc. The zinc uses protection by physical barrier to prevent the iron from gaining access to oxygen and air, but if the zinc is scratched it will use sacrificial protection as zinc is more reactive
What is the difference between corrosion and rusting?
Corrosion is when metals are worn out but rust is when iron wears out
What effect does salt used on roads in winter have on rusting in cars?
Salt speeds up the rusting process
Where could galvanising be used? (Give 2 answers)
Girders for bridges, car body panels
