Module 3: Periodic Table and Qualitative Analysis V2 Flashcards
Define the term first ionisation energy
The first ionisation energy is the energy needed to remove 1 mole of electrons ✓
from 1 mole of gaseous atoms ✓
to form 1 mole of gaseous 1+ ions ✓
Write an equation, with state symbols, to represent the first ionisation energy of Magnesium
Don’t forget that they are gaseous
Write an equation, with state symbols, to represent the fourth ionisation energy of sodium
Don’t forget that they are gaseous
Define what is meant by the “second ionisation energy”
The second ionisation is the energy needed to remove 1 electron from each ion ✓
in 1 mole of gaseous 1+ ions ✓
to form 1 mole of gaseous 2+ ions ✓
Explain why the first ionisation energy, is an endothermic process
Energy is required to overcome electrostatic attraction between positive nucleus and negative electron ✓
Describe and explain the trend in first ionisation energy going down the group
First ionisation energy decreases ✓
Number of shells increases, so shielding increases ✓
Atomic radius increases down the group ✓
Nuclear charge increases down the group, but is outweighed by increase in atomic radius and shielding ✓
Nuclear attraction for outer electron decreases, so electron more easily lost ✓
Remember, NANCARS: When talking about how easy it is to lose or gain an electron
Describe and explain the trend in first ionisation energy going across the period.
First ionisation energy increases ✓
Nuclear charge increases ✓
Shielding is similar, outermost electron is being removed from the same shell ✓
Atomic radius decreases. ✓
Greater nuclear attraction for outer electron ✓
Remember, NANCARS: When talking about how easy it is to lose or gain an electron
Explain why first ionisation energy decreases between groups 2 to 3 (Mg to Al)
Mg has outer electron in 3s sub-shell and Al has outer electron in 3p sub-shell ✓
3p sub-shell has higher energy than 3s sub-shell. ✓
There is a slight increase in shielding which outweighs the increase in nuclear charge. ✓
Remember, NANCARS: When talking about how easy it is to lose or gain an electron. It may be helpful to draw stuff out.
Explain why first ionisation energy decreases between groups 5 to 6 (P to S)
Shielding is identical in phosphorous and sulfur atoms and electron is being removed from 3p-subshell. ✓
In sulfur, the electron is easier to remove – lower ionisation energy. ✓
Orbital has 2 electrons – repulsion between the two electrons. ✓
Remember, NANCARS: When talking about how easy it is to lose or gain an electron. It may be helpful to draw stuff out.
Sketch a graph to show how ionisation energy changes across period 3.
Predict where you would expect lithium to be by adding an additional cross above Sodium.
Li would be much higher compared to the rest, as it has one less shell. Li is much greater in ionisation energy due to having less shielding and being closer to the nucleus.
Describe and explain the trend in successive ionisation energies
Increases as more electrons are removed. ✓
Electrons are removed from a more positive ion ✓
Attraction between remaining electrons and nucleus increases. Radius also decreases. ✓
more energy is needed to remove the next electron. ✓
Same number of protons, same nuclear charge attracting fewer electrons. ✓
The successive ionisation energies of element X is shown below. State and explain what group element X belongs to.
Group 5
Big jumps are caused when a new shell is broken into ✓
Electron removed from a shell closer to the nucleus ✓
Describe and explain the trend in reactivity going down the group for group 1 and 2 metals.
Increases down the group ✓
Number of shells increases, so shielding increases ✓
Atomic radius increases down the group ✓
Nuclear charge increases down the group, but is outweighed by increase in atomic radius and shielding ✓
Nuclear attraction for outer electron decreases, so less is energy is required to remove electrons✓
Remember, NANCARS: When talking about how easy it is to lose or gain an electron. It may be helpful to draw stuff out.
Write a balanced equation for the reaction of calcium with water and state what observations you would observe.
Fizzing ✓
Solid dissolves ✓
Write an equation for the reaction of Calcium with oxygen.
Write an equation to show how the product above can react with water to produce calcium hydroxide.
State and explain a use of calcium hydroxide
Used in agriculture ✓
to neutralise acidic soils ✓
State and explain a use of magnesium hydroxide and calcium carbonate
Antacids ✓
Neutralises excess stomach acid ✓
State and explain a use of barium sulfate
Barium meals ✓
barium sulfate is insoluble ✓
Describe and explain the trend in atomic radius going across the period.
Decreases across a period ✓
Number of protons / nuclear charge increases ✓
Outer electrons are in the same shell and have similar shielding ✓
Stronger nuclear attraction and electrons are drawn in more ✓
Remember, NANCARS: When talking about how easy it is to lose or gain an electron. It may be helpful to draw stuff out.
Describe and explain the trend in atomic radius going down the group
Increases down the group ✓
Number of shells increases ✓
Describe and explain the trend in melting and boiling points going down group 7
Increases down group 8 ✓
Number of electrons and atomic radius increases ✓
Strength of induced dipole-dipole interactions between atoms increases ✓
which require more energy to overcome ✓
Could use “London forces”
Sketch a graph to show how boiling points change across period 3
Explain why the melting points increases from sodium to aluminum.
Number of delocalised electrons increases ✓
Charge on positive ion increases ✓
Metallic bonding, electrostatic attraction between the positive metal ion and delocalised electrons, gets stronger ✓
Explain why the conductivity increases in period 3, from Na to Al.
Number of delocalised electrons increases ✓
Explain why boron has a higher melting and boiling point compared to nitrogen
Boron has a giant covalent lattice with lots of strong covalent bonds ✓
N2 has simple covalent lattice and induced dipole-dipole interactions between molecules ✓
Covalent bonds require more energy to overcome ✓
Explain why phosphorous has a higher melting and boiling point compared to argon
Phosphorous has a simple covalent lattice and induced dipole-dipole interactions between molecules ✓
Argon has induced dipole-dipole interactions between atoms ✓
Phosphorous more atoms and electrons ✓
hence stronger induced dipole-dipole interactions between molecules which requires more energy to overcome ✓
Explain why a nitrogen atom is larger than an oxygen atom.
Nitrogen has less protons than oxygen and has a weaker nuclear charge ✓
Both have similar shielding ✓
Weaker nuclear attraction in nitrogen and shell is drawn in less by nuclear charge ✓
Explain why phosphorous has a lower boiling point than sulfur.
Sulfer has more atoms and more electrons ✓
Stronger induced dipole-dipole interactions between molecules ✓
… which require more energy to overcome ✓
Describe and explain the trend in boiling and melting points going down group 7.
Increases down group 7 ✓
Number of electrons and atomic radius increases ✓
Strength of induced dipole-dipole interactions between molecules increases ✓
which require more energy to overcome ✓
Describe and explain the trend in volatility going down group 7.
Decreases down group 7 ✓
Number of electrons and atomic radius increases ✓
Strength of induced dipole-dipole interactions between molecules increases ✓
Which require more energy to overcome ✓
Describe and explain the trend in reactivity going down group 7.
Halogens are less reactive and less oxidising down the group ✓
Atomic radius increases ✓
Outer electrons are further away from the nucleus and are more shielded from the nucleus ✓
Less nuclear attraction, so more difficult for larger atoms to attract electrons needed to form an ion ✓
Remember, NANCARS: When talking about how easy it is to lose or gain an electron. It may be helpful to draw stuff out.
Explain how you could investigate the reactivity of the halogens.
Oxidising strengths seen in displacement reactions with halide ions ✓
More reactive halogens will oxidise and displace halide ions of less reactive halogens ✓
Write an ionic equation for the reaction between chlorine and potassium bromide.
If needed, include observations in your answer, in aqueous conditions and when using an organic solvent i.e. cyclohexane.
Write an ionic equation for the reaction between chlorine and magnesium iodide.
If needed, include observations in your answer, in aqueous conditions and when using an organic solvent i.e. cyclohexane.
Write an ionic equation for the reaction between bromine and lithium iodide.
If needed, include observations in your answer, in aqueous conditions and when using an organic solvent i.e. cyclohexane.
State the colour change from the following mixtures, if any and write an ionic equation for the reaction between the following:
a) Magnesium iodide added to a test tube containing chlorine.
b) Sodium iodide added to a test tube containing bromine.
c) Potassium bromide added to a test tube containing chlorine.
d) magnesium chlorine added to a test tube containing bromine.
State symbols needed for an ionic equation - always
For the following reactions, write half equations for both the oxidation and reduction process.
You are provided with 3 solids, which could contain either sodium chloride, magnesium bromide or lithium iodide.
Plan an investigation to deduce the identity of the solids.
Dissolve unknown halide in water with nitric acid ✓
Add aqueous solution of silver nitrate ✓
Silver ions from the silver nitrate reacts with the halide ions forming a silver halide precipitate ✓
Silver halide precipitates are coloured with the colour intensity increasing from Cl- to I-. Colour tells you which halide ion is present. ✓
If it is too difficult to decide on a colour, first add dilute ammonia solution, then check with concentrated ammonia solution ✓
as the halide ions have different solubilities in ammonia. ✓
Silver nitrate solution is added to a beaker of solution containing NaCl, NaBr and NaI. Concentrated ammonia solution is then added, and the resulting mixture is filtered.
What compound(s) are contained within the residue on the filter paper?
AgI ✓
Silver nitrate solution is added to a beaker of solution containing NaCl, NaBr and NaI. Dilute ammonia solution is then added, and the resulting mixture is filtered.
What compound(s) are contained within the residue on the filter paper?
AgBr and AgI ✓
Explain how you can test for chloride ions.
Write an ionic equation to support your answer.
State the name of the product formed and observations seen.
Add nitric acid followed by silver nitrate solution to sample ✓
White precipitate formed ✓
Silver chloride ✓
## Footnote
State symbols needed for an ionic equation - always
Explain how you can test for bromide ions.
Write an ionic equation to support your answer.
State the name of the product formed and observations seen.
Add nitric acid followed by silver nitrate solution to sample ✓
Cream precipitate formed ✓
Silver bromide ✓
## Footnote
State symbols needed for an ionic equation - always
Explain how you can test for iodide ions.
Write an ionic equation to support your answer.
State the name of the product formed and observations seen.
Add nitric acid followed by silver nitrate solution to sample ✓
Yellow precipitate formed ✓
Silver iodide ✓
## Footnote
State symbols needed for an ionic equation - always
Define what is meant by a “precipitation reaction”
where aqueous ions react together to form a solid precipitate ✓
A student tests conducts a test for halide ions, but the precipitate appears to be cream-yellow.
State what they could do next to confirm the presence of bromide or iodide ions.
Add concentrated ammonia solution ✓
Precipitate dissolves if bromide ions present ✓
No visible change if iodide ions present ✓
Write an equation for the formation of bleach and give the conditions required for the reaction.
cold ✓ dilute aqueous NaOH ✓
Using oxidation states, explain how the following reaction is defined as being a disproportionation reaction
The simultaneous oxidation and reduction of the same element ✓
O in H2O2 is -1… O in H2O is -2… and O in O2 is 0 ✓
O is oxidised from -1 to 0 oxidation state AND ✓
O is reduced from -1 to -2 oxidation state ✓
The first five successive ionisation energies of an element Y are shown below.
What is the formula of a chloride of Y?
YCl ✓
The first four ionisation energies of a Period 3 element X are shown in the table.
Element X is reacted with chlorine.
What is the formula of the chloride formed?
XCl2
Compound A has the following percentage composition by mass: Ca, 81.10%; N, 18.90%.
A student reacts compound A with water to form alkaline gas B and alkali C.
Identify A, B and C and write the equation for the reaction of compound A with water.
This question refers to the elements in the first three periods (H → Ar) of the Periodic Table.
Select an element from the first three periods that fits each of the following descriptions.
The element in Period 3 which has the successive ionisation energies shown below.
Magnesium/Mg ✓
Large increase from 2nd and 3rd showing 3rd electron is taken from a shell closer to the nucleus.
Therefore 2 electrons in its outer shell, so must be in group 2.
This question refers to the elements in the first three periods (H → Ar) of the Periodic Table.
Select an element from the first three periods that fits each of the following descriptions.
A molecule, which has a density of 1.33 × 10−3 g cm−3 at room temperature and pressure.
Oxygen/O ✓
This question refers to the elements in the first three periods (H → Ar) of the Periodic Table.
Select an element from the first three periods that fits each of the following descriptions.
The element with an average atomic mass of 6.63 x 10^-23
Argon/ Ar ✓
The average atomic mass is the mass of 1 atom, in g.
Add crosses to the graph below to show the first 11 ionisation energies of Magnesium. You do not have to join the crosses.
Make sure there is a big jump between 2-3 and 10-11 as remove electrons from a shell closer to the nucleus.
Write the equation, including state symbols for the reaction between
a) Barium and oxygen. Include a name for this reaction.
b) Barium oxide and water.
c) Barium hydroxide and hydrochloric acid. Include a name for this reaction.
d) Barium and hydrochloric acid. Include a name for this reaction.
e) Barium and water. Include a name for this reaction.
Complete the following sketch, to show the ionisation energies across period 3.
