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WorksheetsC4 Chemical changes - Higher
Total questions: 62
Worksheet time: 31mins
What is the reactivity series?
A list of metals ordered by their solubility
A list of non metals ordered by their reactivity
A list of elements ordered by their reactivity
A list of atoms ordered by their reactivity
How can metals be placed in order of their reactivity?
Add the metals to water or acid and see which ones react the most (by how much fizzing there is)
Add the metals to oil and see which ones burn the most
Add the metals to acid and see which ones make salt and water
Add the metals to water and leave until they rust
What is the name for a reaction where oxygen is removed from a compound?
Replacement
Displacement
Oxidation
Reduction
Explain why zinc can be extracted from zinc oxide with carbon but magnesium cannot be extracted from magnesium oxide with carbon
Carbon is more reactive than Magnesium
Magnesium is more reactive than carbon
Zinc is more reactive than carbon
Carbon is less reactive than zinc
Explain why gold and silver can be found naturally in the Earth's crust
It is shiny
It is expensive
It is rare
It is very unreactive
What process is used to extract metals more reactive than carbon?
Electrolysis
Displacement
Photosynthesis
Chromatography
Define an ore
What is used to row a boat with
A rock
A material containing enough metal in it for it to be economically worthwhile to extract the metal.
Define a displacement reaction
A reversible reaction
A reaction in which a more reactive element takes the place of a less reactive element in one of its compounds or in solution
A reaction which relies on heat
When metals are rearranged into different places.
Define oxidation in the context of loss and gain of electrons
Oxidation is the loss of electrons
Oxidation is the gain of electrons
Oxidation is the loss of oxygen
Oxidation is the reduction of oxygen
Define reduction in the context of loss and gain of electrons
Reduction is the gain of electrons
Reduction is the loss of electrons
Reduction is the gain of oxygen
Reduction is the oxidation of electrons
Which two half equations show the reaction below:
Al³⁺ + Fe → Fe³⁺ + Al
Al³⁺ - 3e⁻ → Al, Fe → Fe³⁺ - 3e-
Al³⁺ + 3e⁻ → Al, Fe → Fe³⁺ - 3e-
Al³⁺ - 3e⁻ → Al, Fe → Fe³⁺ + 3e-
Al³⁺ + 3e⁻ → Al, Fe → Fe³⁺ + 3e-
Define acid in terms of pH
A substance with a pH of more than 7
A substance with a pH of less than 7
A substance with a pH of 7
A substance with a pH between 1 and 14
Define acids in terms of ions
A substance which releases H⁺ ions in solution
A substance which releases OH- ions in solution
A substance which releases SO4- ions in solution
A substance which releases NO3- ions in solution
What does (aq) stand for?
aqua
aqueous
aqa exam board
aqueduct
State the acid with the formula H2SO4
Sulfuric acid
Hydrogen sulphide acid
Hydrogen sulfuric acid
Sulfur oxide acid
Which ions does HCl acid form in solution?
H⁺ and Cl⁻
2H⁺ and SO₄²⁻
H⁺ and NO₃⁻
2H⁺ and Cl⁻
What is a neutral solution?
A solution with a pH of 1
A solution with a pH of 14
A solution with a pH of 17
A solution with a pH of 7
How do you measure pH?
With a quadrat
With sodium hydroxide solution
With an indicator or pH probe.
With a meter ruler
What is a base?
The bottom of an object
A metal oxide, hydroxide or carbonate that will react with an acid. E.g. copper oxide
A metal
A non-metal
What is an alkali?
A soluble base
An insoluble base
Which ions are always present in a solution of an alkali?
NO3⁻
SO42⁻
H+
OH⁻
What type of salts are formed by the three main acids?
Hydrochloric acid produces chlorates, sulphuric acid = sulphates, nitric acid = nitrates
Hydrochloric acid produces chlorides, sulphuric acid = sulphates, nitric acid = nitrates
Hydrochloric acid produces chlorides, sulphuric acid = sulphides, nitric acid = nitrides
What is a neutralisation reaction?
A reaction involving a gas that results in a neutral solution
A reaction involving an acid that results in a neutral solution
A reaction involving a metal that results in a neutral solution
A reaction involving a non metal that results in a neutral solution
Which ions always react together in a neutralisation reactions between acids and alkalis?
H⁺ and OH⁻
OH⁺ and H⁻
NO3- and OH⁻
Na+ and Cl-
Show the equation showing the reaction between H⁺ and OH⁻ ions
H- + OH+ → H₂O
H⁺ - OH⁻ → H₂O
H⁺ + OH⁻ → H₂O
H⁺ + OH⁻ → H₂OH
metal + acid →
→ salt + hydrogen
→ salt + carbon dioxide
→ metal + hydrogen
→ metal + oxygen
metal hydroxide + acid →
→ salt + water
→ salt + hydrogen
→ salt + water + carbon dioxide
→ salt + oxygen
metal oxide + acid →
→ salt + hydrogen
→ salt + water
→ salt + water + carbon dioxide
→ salt + oxygen
metal carbonate + acid →
→ salt + water
→ salt + hydrogen
→ salt + water + carbon dioxide
→ salt + oxygen
How do you make a soluble salt from an acid?
React the acid with oxygen
React the acid with hydrogen
React the acid with water
React the acid with a base
If a salt is in solution, how do you extract it as a solid?
Evaporate off the water.
Filter the solution.
Use chromatography.
Dissolve the salt in a solvent.
What is a strong acid?
An acid which partially splits up into its ions in water.
An acid with a high concentration
An acid which completely splits up into its ions in water.
An acid with a high pH
What is a weak acid?
An acid which has a low pH
An acid where all the molecules completely ionise.
An acid which has a low concentration
An acid which will have some molecules which do not split up into their ions, partially ionise.
What is a dilute acid?
An acid which completely splits up into its ions in water.
An acid which partially splits up into its ions in water.
An acid where there are fewer acid particles in the water.
An acid where there are lots of acid particles in the water.
What is a concentrated acid?
An acid where there are lots of acid particles in the water.
An acid where there are fewer acid particles in the water.
An acid which completely splits up into its ions in water.
An acid which partially splits up into its ions in water.
Which ions are in NaCl (s)?
Na⁺ and H⁻
H⁺ and Cl⁻
Na⁺ and Cl⁻
Na⁺ Cl⁻ H+ and OH-
Which ions are in CaCO₃ (s)?
Cu²⁺ and CO₃²⁻
H⁺ and Cl⁻
Ca²⁺ and CO₃²⁻
Ca²⁺ CO₃²⁻ H+ and OH-
What is the formula of calcium chloride?
CaCl₂
CaCl
CACL
Ca2Cl
What is the formula of sodium sulphate?
S₂SO₄
NaSO
S₂SO₄
Na₂SO₄
Is this process oxidation or reduction? Al → Al³⁺ + 3e⁻
oxidation
reduction
Is this process oxidation or reduction? Na⁺ + e⁻ → Na
Oxidation
Reduction
What is electrolysis?
delocalised electrons carrying the charge
Separation of solid and liquid
Using electricity to break down a substance
The decomposition of ionic compounds using carbon.
What happens to an ionic substance when it is melted or dissolved in water?
The ions become free to move around
The electrons become free to move around
What is the name for the positive electrode?
cathode
anode
aliode
lynode
What is the name for the negative anode?
cathode
anode
aliode
lynode
Which electrode do the positive ions move to?
cathode
anode
aliode
lynode
Which electrode do the negative ions move to?
cathode
anode
aliode
lynode
At which electrode would Zn²+(aq) turn into Zn(s)?
cathode
anode
aliode
lynode
At which electrode would Cl⁻(aq) turn into Cl₂(g)?
cathode
anode
aliode
lynode
Balance the equation: Al³⁺ + e⁻ → Al
Al³⁺ + e⁻ → 3Al
Al³⁺ + 2e⁻ → Al
Al³⁺ + e⁻ → Al
Al³⁺ + 3e⁻ → Al
Balance the equation: Cl⁻ → Cl₂ + e⁻
Cl⁻ → Cl₂ + 2e⁻
2Cl⁻ → Cl₂ + 2e⁻
Cl⁻ → Cl₂ + e⁻
2Cl⁻ → Cl₂ + e⁻
Balance the equation: O²⁻ → O₂ + e⁻
2O²⁻ → 2O₂ + 4e⁻
2O²⁻ → O₂ + e⁻
2O²⁻ → O₂ + 4e⁻
O²⁻ → O₂ + 4e⁻
What will be the products for the electrolysis of molten iron bromide?
Iron and iodine
Iron and chlorine
Iron and bromine
Iron and fluorine
What will be the products for the electrolysis of molten zinc oxide?
Zinc and sulfur
Zinc and oxygen
Zinc and hydrogen
Zinc and chlorine
For the extraction of which metals is electrolysis needed?
metalloids
less reactive metals, e.g silver, gold, platinum
mid reactivity metals, e.g zinc, iron, tin
ones more reactive than carbon, e.g. aluminium
What is a disadvantage of using electrolysis to extract metals?
The metals are too reactive.
Operation of the process requires skilled scientists.
Requires a large amount of energy to melt the compounds and to produce the necessary electricity.
The equipment is too expensive to maintain.
Why is aluminium oxide mixed with cryolite when extracting aluminium?
To lower the melting point
To increase the rate of reaction
To react with impurities
To provide energy.
What is produced at the anode and cathode in the electrolysis of aluminium oxide?
Aluminium at the cathode and carbon dioxide at the anode
Aluminium at the cathode and hydrogen at the anode
Zinc at the cathode and oxygen at the anode
Aluminium at the cathode and oxygen at the anode
Why does the anode need to be replaced in the electrolysis of aluminium oxide?
The oxygen reacts with the carbon electrode to produce carbon dioxide so the blocks reduce in size.
The anode blocks become coated and no longer conduct.
The anode blocks dry out over time.
To keep the anode blocks fresh.
In the electrolysis of sodium chloride solution, what are the products?
Sodium and hydrogen gas
Sodium and chlorine gas
Chlorine gas and hydrogen gas
Oxygen gas and hydrogen gas
Why is sodium not produced in the electrolysis of sodium chloride solution?
Hydrogen is more reactive than sodium so hydrogen is produced instead.
It is more reactive than hydrogen so hydrogen is produced instead.
What is produced at the anode in electrolysis of solutions?
Oxygen gas
Hydroxide (OH-) because it is the least reactive ion
Always a halogen
Either a halogen or oxygen (when there is no halogen present)
