Inorganic Chemistry

Question 1

Group 2 ionisation trend

Answer 1

Decreases down the group.

Due to more shielding and greater atomic radius. Therefore weaker attraction and eaiaser to lose,

Question 2

Group 2 reactivity trend

Answer 2

Increases down the group. Outer electron is further away frome the nucleus, ionisation decreases, and electron is lost more readily. Lower activation energy

Question 3

Group 2 water reactions

Answer 3

Reduce to form hydroxides and hydrogen gas. Mg reacts slowly with cold water, ca quicker, sr and ba faster,
Also reacts with steam. Produces m(oh)2 and h2,

Question 4

Groups 2 with chlorine

Answer 4

Redox forms Metal chloride

Ca plus cl2 goes to cacl2

Question 5

Group 2 with oxygen

Answer 5

Forms metal oxide.

Mg with o2 goes to 2mgo

Question 6

Solubility group 2 hydroxides

Answer 6

Increases
Mg(oh)2 barely soluble. Ba is soluble, and dissolved to form alkaline solution,
Ba(oh)2 plus water goes to baerium ions and hydroxide ion

Question 7

What is ca(oh)2?

Answer 7

Slaked lime. Basic. Raises ph of soils.

Question 8

What is mg(oh)2

Answer 8

Medicine, and excess stomach acid, milk of magnesia. Neutralises stomach acid.

Question 9

Solubility of group 2 sulfates

Answer 9

Decreases.

Baso4 is insoluble. Used in medicine, ba meal.

Question 10

Why is baso4 used in medicine?

Answer 10

Ba meal. Eat it and it coats the gut. Shows up on x Ray. Low solubility so even though highly toxic, it can be used,

Question 11

Thermal stability of nitrates and carbonates group 2

Answer 11

Becomes more stable going down the group.
Xco3 goes to xo and co2.
2x(no3)2 goes to 2xo and 4no2 and o2.
Cations become larger going down the group. Require more energy to be decomposed.

Question 12

Thermal stability of group q carbonates and nitrates

Answer 12

More stable than group 2. Become more stable going down the group.
X2co3 goes to x2o and co2.
2xno3 goes to 2xno2 and o2.
Lithium produces lithium oxide and no2 and o2.
Cations larger down the group, require more energy to decompose.

Question 13

Colour of the lithium fame

Answer 13

Scarlet red

Question 14

Na flame colour

Answer 14

Yellow

Question 15

K flame

Answer 15

Lilac

Question 16

Rb flame

Answer 16

Red

Question 17

Cs flame

Answer 17

Blue

Question 18

Ca flame

Answer 18

Brick red

Question 19

Sr flame

Answer 19

Crimson

Question 20

Ba flame

Answer 20

Apple green

Question 21

What happens when metals are heated?

Answer 21

The electron in. The ion jumps to an upper energy level, becoming unstable. When the Electron falls back down to the original, it emits energy in the form of light. The colour of the light depends on the wavelength, and therefore forms different colours for every metal

Question 22

Group 7 melting point and boiling point

Answer 22

Have Low boiling point.
Due to only weak intermolecular forces,
Increases down the group due to In erase in London forces.

Question 23

Electronegativity trend in group 7

Answer 23

Decreases down the group, as atomic radius increases

Question 24

Why is there a smaller atomic radius in group 7?

Answer 24

Smaller atomic radius, the electrons in covalent bond closer to nucleus, and strongly attracted. More important than the number of protons, which increases down the group

Question 25

What are the group 7 ions?

Answer 25

1- ions. Noble gas configuration. Very reactive due to this need to gain an electron.

Question 26

Oxidising power in group 7

Answer 26

Decreases down the group, as e neg decreases, the giver halogens oxidise loser halogens. This can be seen by the colour of 2 halogens in solution.

Question 27

Reducing agents in group 7

Answer 27

Halides are reducing agents, lower halogens are less e neg and therefore stronger reducing agents,
The colour will show of the less reactive halogen.

Question 28

How is the reducing power shown in group 7?

Answer 28

Reaction of sodium halides with concentrated sulfuric acid.
Nacl; no redox.
Nabr: yes, sulfur +6 to +4.
Produces water, diatomic group 7 molecule, and so2.
Nai; yes, sulfur +6 to +4, and 0 to -2. Produces water, h2s and diatomic molecule.
0 to -2 forms solid sulfur

Question 29

Colours of group 7 waters in quesous solutions

Answer 29

Cl water - pale yellow, green to colourless
Be water - yellow orange to colourless
I water - brown to colourless s

Question 30

Colours of 7 waters with hydrocarbons

Answer 30

Cl- colourless to pale yellow green
Br - colourless to place yellow and orange
I - colourless to pale purple.

Question 31

Ag no3 test with group 7

Answer 31

Dissolve halide in water.
Add dilute HNO3 to remove any carbonate or hydroxide impurities, as this would form silver carbonate and s8ver hydroxide.
Add aqueous silver nitrate.
Colour ppt shows. If hard to distinguish, add concentrated NH3.

Question 32

Colours of AgX

Answer 32

Cl goes white
Be goes cream
I goes yellow.
These are th colours of the ions in the AgX

Question 33

Which groups 7 halides are soluble in dilute NH3

Answer 33

Cl yes
Br no
I no

Question 34

Which groups 7 halides are soluble in concentrated NH3

Answer 34

Cl yes
Br yes
I no

Question 35

Groups 7 oxidation reactions with group 1 and 2

Answer 35

Mg with cl2 goes to mgcl2.

Halogen b3comes reduces, and metal becomes oxidised. Halogen is the oxidising agent

Question 36

Group 7 disproportionation with with water

Answer 36

Oxidation and reduction happens.
Cl reacts irreversibly to form HCl which is reduced Cl, and HClO with is oxidised Cl.
Cl2 and H2O goes to HCl and HClO

Question 37

What is HClO

Answer 37

An acid, bleach. Kills bacteria by oxidation.

Question 38

Group 7 with dilute NaOH

Answer 38

React to form NaX,
Eg,
Cl reacts with NaOH to form NaCl and NaClO and water,
This is a,so a bleach

Question 39

Group 7 with hot alkali

Answer 39

Forms naBrO3 and NaBr and water,

Question 40

Halogens with Sulfirc acid

Answer 40

Undergo neutralisation, NaX and Sulfuric acid goes to NaHSO4 and HX,
Only Br and I are strong enough reducing agents to reduce from +6 in sulfuric acid to +4 so2, and s8,0. And -2 H2S