Periodic table And Energy Module3 AS

Question 1

What happens to the reactivity of group 17 halogens as you go down the group

Answer 1

It decreases as increased atomic radius and more electron shielding thus harder to gain man electron as nuclear attraction decreases

Question 2

What are the advantages and disadvantages of using chlorine

Answer 2

Advantage: Kills Bacteria

Disadvantage: Forms Toxic Compounds

Question 3

What forms when a halogen reacts with NAOH and what are the conditions?

Answer 3

Salt + Chromate Solution + Water
Conditions: Cold and Solid NaOH

Question 4

What is a displacement reaction

Answer 4

When a more reactive elements displaces a less reactive one in a solution

Question 5

What colour does Potassium Iodide form when displaced

Answer 5

Brown

Question 6

What colour does Potassium Bromide form when displaced

Answer 6

Yellow

Question 7

What colour does Potassium Chloride form when displaced

Answer 7

Green

Question 8

What otganic solvent colour does Iodine form when displaced

Answer 8

Purple

Question 9

What organic solvent colour does Bromine form when displaced/reacts with thyself

Answer 9

Yellow

Question 10

What colour does chlorine form when displaced/reacts with thyself

Answer 10

Colourless

Question 11

How would you test for carbonates

Answer 11

Add Dilte HCL in a test tube and if Effervescence/bubbling occurs, it indicates the prescence of carbonate as CO2 is produced when carbonate reacts w/ HCL and to confirm it, bubbling the gas through limewater through a delivery tube and if it turns milky/cloud, it confirms the prescence of CO2

Question 12

How would you tes for sulfates

Answer 12

Add Dilute HCL and Barium Chloride and if sulfates present, a white precipitate shall form

Question 13

How would you test for halide ions

Answer 13

Add dilute HCL and nitric acid and silver nitrate

SIlver chloride is white
Silver bromide is cream
Silver iodide is yellow

Question 14

How would you confirm prescence of those halide ions

Answer 14

Chlorine dissolves in DILUTE ammonia
Bromine dissolves in CONCENTRATED ammonia
Iodine does not dissolve in any…

Question 15

How would you test for ammonium ions

Answer 15

Warm with NaOH but not ammonia to generate ammonia gas and put it through litmus paper, which will turn it blue

Question 16

State the ionic equation for a displacement reactions between chlorine and bromine

Answer 16

2Br- (in the solution) and Cl2(elemental) –> 2Cl- + Br2

Question 17

What is the defenition of First Ionisation Energy

Answer 17

Amount of energy required to remove 1 mol. of electrons from 1 mol. of gaseous atoms

Question 18

Why does tne boiling point increase across a period for elemtns w/ metalic bonds

Answer 18

More electrons across the group thus more electrons become delocalised thus more metalic bonds form forming stronger metalic bonds whioch require more energy to overcome and size of atom increases

Question 19

Why can magnesium bromide conduct electricity in aqueous state but not in solid

Answer 19

In aqueous: Ions are mobile and free to move aroud the structure carrying chargw
In Solid: Ions are fixed in position in a lattice

Question 20

Why does magnesium bromide have a high melting point

Answer 20

As it is a giant ionic lattice containing strong electrosatic bonds between oppositely charged ionswhich require a lot of energy to overcome

Question 21

Why does the first ionisation energy of boron decrease going from berillium to boron

Answer 21

As a new sub shell is being filled –> 1s2 2s2 sp1, thus it requires less energy to lose an elec

Question 22

Why does the first ionisation energy decrease going from nitrogen to oxygen

Answer 22

As oxygen has an orbital where it has a pair of electrons which repel eachother thus it is easier to lose an electron

Question 23

What happens to the atomic radius across a period

Answer 23

N. of protons across a group increase thus nuclear attraction increases and n. of shells stay present so electron shielding remains constant thus atomic radius decreases

Question 24

Why does reactivity increase going down group 2

Answer 24

As elec. shielding increases down the group thus nuclear attraction decreases thus easier to lose an electron

Question 25

What is the group 2(Mg) reaction with water

Answer 25

Mg + H20 –> 2MgO + H2

Question 26

What is the Group 2(Mg) reaction with Oxygen

Answer 26

2Mg + O2 –> 2MgO

Question 27

What is the group 2 reaction with dilute acids (H2S04)

Answer 27

Mg + H2S04 –> MgSO4 + H2

Question 28

What is the reaction between group 2 oxides and water

Answer 28

MgO and H20 –> Mg(OH)2

Question 29

What are the 2 uses of Group 2 Oxides

Answer 29

Used to neutralise acid soils
Used in some indigestion tablets – antacticds

Question 30

What type of atom does LDF occur between

Answer 30

Between Molecules

Question 31

What type of structure are metals

Answer 31

Giant lattices

Question 32

What does it mean if an element has a high first ionisation energy

Answer 32

It means that it is Harder to lose elec.
means that it has greater nuclear attraction and low elec. shielding and small atomic radius

Question 33

How does sulfur Phosphorous and chlorien exist

Answer 33

SUlfur – S8
Phosphorous - P4
Chlorine - Cl2

Question 34

Why does sulfur phosphorous and chlorine not conduct elec.

Answer 34

As they have no free elc as theyre in S8 P4 etc.

Question 35

How does metalic bonding occur

Answer 35

As there is nuclear charge in metals due to the electrons in outer shell thus the nuclear charge causes attraction between oppositely charged ions

Question 36

Write ionic equation for carbonates

Answer 36

CO3 2- + 2H+ –> CO2 + H20

Question 37

Write ionic equation to test for halide ions

Answer 37

Ag+ + Br- –> AgBr

Question 38

Write ionic equation for sulfates

Answer 38

SO4 2- + Ba 2+ –> BaSO4