Group 2 and 7

Question 1

what factors affect the ionisation energies of the alkali and alkaline earth metals?

Answer 1

size of the ion and charge of the ion

Question 2

size of the ion ….. down group 2, why

Answer 2

increases, due to more shielding and less nuclear attraction

Question 3

group 2 metal + water

Answer 3

metal hydroxide + hydrogen

Question 4

group 2 metal + oxygen

Answer 4

metal oxide

Question 5

group 2 metal + chlorine

Answer 5

metal chloride

Question 6

reactivity of group 2 metal oxides …… down the group

Answer 6

increases

Question 7

group 2 metal oxide + water

Answer 7

metal hydroxide

Question 8

group 2 metal oxide + acid

Answer 8

salt + water

Question 9

group 2 metal hydroxide + acid

Answer 9

salt + water

Question 10

solubility of group 2 metal hydroxides ….. down the group

Answer 10

increases

Question 11

magnesium hydroxide uses

Answer 11

as a laxative or for indigestion

Question 12

solubility of group 2 metal sulphates ……. down the group

Answer 12

decreases

Question 13

barium sulphate uses

Answer 13

barium meal to cause contrast in x rays

Question 14

Thermal stability

Answer 14

a measure of resistance to thermal decomposition.

Question 15

Thermal decomposition

Answer 15

when a substance breaks down when heated.

Question 16

Polarizing power of a cation

Answer 16

its ability to pull the electrons from the anion into the space between the ions

Question 17

What 2 things affect polarising power?

Answer 17

size of the ion, charge density

Question 18

how does a cation polarise a carbonate

Answer 18

distorts the carbonate ion. This weakens the C-O bond

Question 19

thermally stability of group 2 metal carbonates …….. down the group, why?

Answer 19

increases due to decreased charge density so decreased polarisation of the carbonate ion

Question 20

thermal decomposition of a group 2 metal carbonate forms

Answer 20

metal oxide + carbon dioxide

Question 21

fluorine properties

Answer 21

pale yellow gas at room temperature

Question 22

chlorine properties

Answer 22

pale green gas at room temperature

Question 23

bromine properties

Answer 23

brown liquid at room temperature

Question 24

iodine properties

Answer 24

black/grey solid at room temperature

Question 25

oxidising power of halogens ……. down the group, why

Answer 25

decreases, due to less nuclear attraction from shielding so harder to attract electrons to accept

Question 26

reducing power of halide ions …… down the group, why

Answer 26

increases, due to less nuclear attraction from shielding so requires less energy to donate an electron

Question 27

Disproportionation

Answer 27

the same atom is simultaneously reduced and oxidised

Question 28

Cl2 + H2O

Answer 28

HCl + HOCl

Question 29

Cl2 + NaOH (cold and dilute)

Answer 29

NaCl + NaClO + H2O

Question 30

3Cl2 + 6NaOH (hot and concentrated)

Answer 30

5NaCl + NaClO3 + 3H2O

Question 31

Li+ flame test

Answer 31

crimson

Question 32

Na+ flame test

Answer 32

Yellow

Question 33

K+ flame test

Answer 33

lilac

Question 34

Ca2+ flame test

Answer 34

red

Question 35

Ba2+ flame test

Answer 35

green

Question 36

Al3+ with NaOH

Answer 36

white ppt, dissolves in excess

Question 37

Ca2+ with NaOH

Answer 37

white ppt, does not dissolve in excess

Question 38

Mg2+ with NaOH

Answer 38

white ppt, does not dissolve in excess

Question 39

Cu2+ with NaOH

Answer 39

pale blue ppt, does not dissolve in excess

Question 40

Fe2+ with NaOH

Answer 40

pale green ppt which turns brown when left, does not dissolve in excess

Question 41

Fe3+ with NaOH

Answer 41

brown ppt, does not dissolve in excess

Question 42

what is used to clean nichrome wire for flame test

Answer 42

concentrated hydrochloric acid

Question 43

where should you hold the wire in a flame test

Answer 43

in the edge of the flame

Question 44

Cl-, Br- and I- colour ppt in silver nitrate

Answer 44

Cl- = white
Br- = cream
I-= yellow

Question 45

positive carbonate test will

Answer 45

turn limewater cloudy

Question 46

positive nitrate test will

Answer 46

turn red litmus paper blue with aluminium powder and sodium hydroxide

Question 47

sulphate test with dilute hydrochloric acid and barium sulphate will form

Answer 47

white precipitate

Question 48

why are flame test colours formed

Answer 48

heat energy excites electrons to a new energy level, a photon is released when they fall back down. This photon directly relates to the wavelength of visible light.