Exam questions Flashcards
Thermal decomposition define
Break down of substances chemically using heat
1 advantage of recycling iron
Conserve iron ore
Steel is made of…
Iron and carbo
Empirical formula
Ratio
Contact process conditions [3]
Temperature: 450c
Pressure: 2atm
Catalyst: Vanadium oxide
carbonate formula
CO3^-2
What is hydrogen oxygen fuel cell and what it does [2]
1) Hydrogen and oxygen react to form water
2) Turns chemical energy into electrical energy
pro & con of hydrogen oxygen fuel cell [2]
1) Does not produce pollutants
2) Requires energy to make hydrogen which comes from fossil fuels
Draw exothermic graph
Reactant higher than product
Negative enthalpy
Draw endothermic graph
Reactant lower than product
Positive enthalpy
Describe process of iron extraction [6]
HIGHER TIER!!
1) Hematite + coke + limestone
2) Air comes in and carbon + oxygen -> carbon dioxide (Release energy for iron oxide reduction
3) carbon dioxide + carbon -> carbon monoxide (Reducing agent)
4) Iron oxide + carbon monoxide -> Iron + carbon dioxide
5) Lime stone undergo thermal decomposition
6) Calcium oxide reacts with silicon dioxide to form slag
chemical equation for carbon monoxide formed in iron extraction
CO2 + C -> 2CO
chemical equation for iron displaced
Fe2O3 + 3CO → 2Fe + 3CO2
Lime stone thermal decomposition chemical equation
CaCO3 → CaO + CO2
Slag formation chemical equation
CaO + SiO2 → CaSiO3
What is and what does a catalytic converter do? [2]
1) Used in vehicles to remove oxides of nitrogen by converting it into nitrogen
2) The oxygen in oxides of nitrogen comes from the air in the car engine
Catalyst for ester
Sulfuric acid
First 4 alkanes
Ethane
Methane
Propane
Butane
1dm3 into cm3
1000dm3
Volume (dm3) formula
Moles x 24
Concentration formula
Mass/volume
Which compounds both contribute to acid rain
sulphur dioxide
oxides of nitrogen
Why is cryolite used in aluminium extraction
Dissolve aluminium oxide
Indicator for water
Cobalt (II) chloride
Bromine water test
In alkane it will be decoloured
Define solute
a substance that is dissolved in a solution
Define solvent
a substance that dissolves a solute, resulting in a solution.
Describe contact process [3]
`1) Sulfur reacts with air sulfur + oxygen → sulfur dioxide
2) Catalyst is used sulfur dioxide + oxygen rightwards (equilibrium) sulfur trioxide
3) Once sulfur trioxide is formed, it undergoes more processes to produce sulfuric acid
Main impurity in iron ore
Silicon (IV) oxide
Displacement reaction
When a more reactive metal displaces another
Reactivity series
Please Stop Calling Me A Careless Zebra Instead Try Learning How Copper Saves Gold
Conditions of contact process [3]
1) 200 kPa
2) Vanadium (V) oxide
3) 450c
Describe two methods by which sulfur dioxide is obtained
M1 burning sulfur (in air)
M2 Roasting sulfide ores (in air)
Define base
Proton acceptor
State the term given to a base which dissolves to form an aqueous solution
Alkali
thymolphthalein changes to what colour when it reacts with a base
Higher than pH 10 gives you blue
Convert from mol/dm3 to g/dm3
Multiply by mass number
State the term given to reactions in which one atom in an alkane is replaced by another
atom
Substitution
State the term given to any reaction which requires ultraviolet light
Photochemical
Write the ionic equation for the reaction when an acid neutralises a soluble base
H+ + OH- -> H2O
Complete the symbol equation to show the dissociation of ethanoic acid.
CH3COOH
CH3COOH
⇌ CH3COO– + H+
Macromolecular structure properties [2]
1) High melting and boiling point
2) Does not conduct electricity when solid or liquid
(Covalent bonded)
Define electrolysis
breakdown by electricity of an ionic compound in aqueous or molten state
Give two reasons why the electrolysis is carried out on aluminium oxide dissolved in
molten cryolite instead of electrolysing molten aluminium oxide only
1) Improves conductivity
2) Lower operating temperature
Sulfuric acid
H2SO4
Flame test Li+
Red
Flame test K+
Yellow
Flame test Li+
Lilac
Flame test Ca2+
Orange-red
Flame test Cu2+
Blue-green
Methyl orange indicator in acid solution
Yellow to orange
Draw the structure of the carboxylic acid containing three carbon atoms.
https://hi-static.z-dn.net/files/d4b/1174be5ed5b54b03b911fc5c060ae6ed.png
The equation for the thermal decomposition of sodium hydrogencarbonate is shown.
2NaHCO3 -> Na2CO3 + H2O + CO2
The Mr of sodium hydrogencarbonate, NaHCO3, is 84.
The Mr of sodium carbonate, Na2CO3, is 106.
In an experiment, 2.1 g of sodium hydrogencarbonate is heated but not all of it decomposes. All of
the carbon dioxide is collected and measured at room temperature and pressure. The total
volume of carbon dioxide produced is 0.21 dm3
.
The volume of 1 mole of a gas at room temperature and pressure is 24 dm3
.
The mass of sodium carbonate produced is 0.93 g