Atomic Structure
Bonding and Structure
Quantitative Chem
Chemical Changes
Energy Changes
100
TRUE or FALSE: Group 7 is called the Noble Gases.
FALSE: they are called the Halogens.
100
What type of compound is SO2?
Simple molecular (covalent)
100
Give the relative atomic mass of Cu
63.5
100
What ion do all acids form when they ionise?
H+
100
TRUE or FALSE: Energy is released to the surroundings in endothermic reactions.
FALSE: Energy is absorbed from the surroundings in endothermic reactions
200
How can a soluble solid be separated from a liquid?
Evaporation OR Crystallisation (OR Distillation)
200
When do ionic compounds conduct electricity? (Both required)
Bonus: explain why.
When they are molten/liquid or they have been dissolved in water
Bonus: the ions are mobile
200
Give the relative formula mass of: SiCl4
170
200
Give the formulae and names of three strong acids.
Nitric Acid - HNO3
Sulfuric Acid - H2SO4
Hydrochloric Acid - HCl
200
Name 2 exothermic processes.
Combustion/burning, neutralisation, condensation, freezing
300
Give the arrangement of electrons around an atom of aluminium.
2,8,3
300
Why do metals conduct electricity? [3 marks]
Metals have delocalised electrons
Which can carry charge
Through the metal's structure
300
How many moles are there in 100g of KBr? (3 sig. fig.)
Mr (KBr) = 119
n = 100 / 119 = 0.840 mol
300
What forms when water reacts with a metal?
Metal hydroxide + Hydrogen gas
300
Does the profile show an exo- or endothermic reaction?
Bonus: Is the energy change is this reaction positive or negative?
Endothermic
Bonus: Positive
400
How many protons, electrons and neutrons are in potassium?
19 protons, 19 electrons, 20 neutrons
400
Why do ionic compounds have a high melting point?
Strong electrostatic attraction between many oppositely charged ions require a large amount of energy to overcome.
400
Give the percentage by mass of Si in SiCl4 (3 sig. fig.)
%mass = (28 /170) x 100%
%mass = 16.5%
400
Give the products of this reaction:
strontium oxide + nitric acid →
strontium oxide + nitric acid → strontium nitrate + water
400
Name 2 endothermic processes.
Thermal decomposition, electrolysis, melting, evaporation
500
Describe the Bohr model of the atom. (2 points required)
At least 2 from:
Positively charged nucleus
Electrons orbit in shells
Mostly empty space/mass concentrated in centre
NOT PERMITTED: Protons or neutrons in the nucleus
500
Explain what happens in terms of electrons when calcium bonds to fluorine. [4 marks]
Ca will lose two electrons
Two F are needed for each Ca
Each F will gain 1 electron
Forming Ca2+ and F- ions
500
What is the concentration in mol/dm3 of a solution containing 8.55 g of Ba(OH)2 dissolved in 250 cm3 of water?
Mr Ba(OH)2 = 171
n = 8.55 / 171 = 0.05 mol
v = 250 / 1000 = 0.25 dm3
c = 0.05 / 0.25 = 0.2 mol/dm3
500
What forms in the electrolysis of aqueous sodium chloride?
Bonus: suggest a pH for the solution leftover.
Cathode: hydrogen gas, H2
Anode: chlorine gas, Cl2
Bonus: greater than 7 (sodium hydroxide solution is leftover)
500
Define the term bond energy.
The energy required to break a specific type of bond OR the energy released when a specific type of bond is formed.