group 2 and 7

Question 1

trend in ionisation energy as you go down group 2

Answer 1

decreases

Question 2

why does IE decrease down group 2

Answer 2

atomic radius increases
shielding increases, decreasing electrostatic attraction to the outer electron, meaning less energy is required to remove it

Question 3

reactivity down group 2

Answer 3

increases as 1IE and 2IE decreases down the group, meaning that it’s easier to form 2+ ions

Question 4

reactions of group 2 with oxygen

Answer 4

2M + O2» 2MO

Question 5

reactions of group 2 with chlorine

Answer 5

M + Cl2&raquo_space; MCl2

Question 6

reactions of group 2 with water
how does this affect the pH
support w an ionic equation

Answer 6

increases reactivity down the group.
Be doesn't react at all, Mg will react slowly w cold water while the rest down the group react more vigorously.
M+2H2O >> M(OH)2
this increases the pH
O2-+H2O >> 2OH-

Question 7

what happens to the solubility of group 2 hydroxides as you go down the group

Answer 7

solubility increases down the group, increasing the pH

Question 8

test for CO2

Answer 8

add aqueous calcium hydroxide and a white precipitate should form
Ca(OH)2 (aq) + CO2 (g)&raquo_space; CaCO3 (s) + H2O

Question 9

uses of group 2 oxides

Answer 9

Mg hydroxide (milk of magnesia) treats indigestion
Ca(OH)2 (lime) raises the pH of soil

Question 10

why is magnesium hydroxide safe for consumption?

Answer 10

although Mg (aq) is toxic to the human body, Mg(OH)2 is insoluble and so non-toxic.

Question 11

equation for lime use in agriculture

Answer 11

Ca(OH)2 + HNO3&raquo_space; Ca(NO3)2 + 2H2O

Question 12

solubility of group 2 sulfates

Answer 12

decreases down the group

Question 13

which group 2 sulfates are insoluble

Answer 13

Sr and Ba

Question 14

use of BaSO4

Answer 14

used as a barium meal in x raying of soft tissue as a contrast fluid.
ordinarily toxic, Ba is insoluble as a sulfate so is safe for consumption

Question 15

how to test for sulfate ions

Answer 15

1. add dilute HCl or HNO3 (to remove CO32-)
2. Add Ba(NO3)2 (source of Ba2+)
3. a white ppt will form

Question 16

what happens to nitrates and carbonates upon heating

Answer 16

they decompose

Question 17

what are the 2 reactions involved in the decomposition of group 2 nitrates

Answer 17

metal nitrate» metal oxide + oxygen + nitrogen dioxide

metal nitrate» metal nitrite + oxygen

Question 18

group 1 nitrates that decompose into nitrogen dioxide

Answer 18

Li ONLY

Question 19

group 2 nitrates that decompose into nitrogen dioxide

Answer 19

ALL OF THEM

Question 20

what colour is nitrogen dioxide

Answer 20

brown

Question 21

factors affecting the decomposition of group 2 nitrates

Answer 21

charge
ionic radius
complexity of nitrates or carbonates

Question 22

how does ionic radius and charge affect stability of group 2

Answer 22

larger, more complex ions of a lower charge are most stable

Question 23

group 1 metals that decompose

Answer 23

Li ONLY

Question 24

group 2 metals that decompose

Answer 24

ALL OF THEM

Question 25

Mp/bp Trend of group 7 | Why?

Answer 25

Increases as you go down group 7 As intermolecular forces become stronger due to larger temporary and induced dipoles (due to more electrons) meaning more energy is needed to break them.

Question 26

Electronegativity Trend down group 7

Answer 26

Decreases Atoms get larger down group. Constant Z eff (=protons- shielding electrons) F is most electronegative element

Question 27

Electronegativity define

Answer 27

The ability of an atom to attract electron density towards itself in a covalent bond.

Question 28

Trend in reactivity down Group 7

Answer 28

Decreases Atomic radius increases, causing electronegativity to decrease But I- is a better reducing agent than F-

Question 29

Chlorine Reactions w group 1 and 2

Answer 29

2Na + Cl2 >> 2NaCl | Mg+Cl2 >> MgCl2

Question 30

Displacement reactions of group 7

Answer 30

Takes place in H2O or cyclohexane | More reactive halogen will displace a less reactive one.

Question 31

How do you see a more distinct colour change in displacement reactions of group 7

Answer 31

Add cyclohexane to see a greater change

Question 32

Colours of group 7 in cyclohexane | Without cyclohexane.

Answer 32

Cl2 > yellow> colourless prior Br2 > brown > yellow prior I2 > purple > yellow prior

Question 33

Disproportionate on define

Answer 33

The Oxidation and reduction of the same element in an equation

Question 34

Uses of chlorides

Answer 34

Weed killer Bleach Disinfectant

Question 35

Trend in oxidising power as you go down group 7

Answer 35

Decreases

Question 36

Trend in reducing power as you go down group 7

Answer 36

Increases

Question 37

3 forms sulfuric acid can be oxidised to

Answer 37

Sulfur dioxide SO2 (4+) Sulfur (0) Sulfur hydride (-2)