the periodic table 1.6

Question 1

what increases going down group 2

Answer 1

-atomic radius
-sheilding (outer electron held less tightly)
- reactivity increases

Question 2

what are the flame tests for group 2

Answer 2

mg- none
ca- orange/brick red
sr - crimson red
ba- green

Question 3

what are the group 1 flame tests

Answer 3

li- red
na- yellow (orangy)
k- lilac

Question 4

group 2 reactions with water

Answer 4

Be - no reaction
mg- steam required
ca- reacts moderately (hydroxide forms)
sr - reacts rapidly (hydroxide forms)
ba- reacts vigorously, (hydroxide formed)

Question 5

whats the equation when group 2 reacts in water

Answer 5

M + 2H2O —>M(OH)2 + H2

Question 6

describe the solubility of group 2 sulphates

Answer 6

decreases down a group
MgSO4 - soluble
CaSO4 - slightly soluble
SrSO4 - insoluble
BaSO4 - insoluble

Question 7

whats the equation for group 2 sulphates

Answer 7

M(aq) 2+ + SO4(aq) 2- ——> MSO4(s)

Question 8

describe the solubility for group 2 hydroxides

Answer 8

increases down a group
mg(OH)2-insoluble
Ca(OH)2 - slightly soluble
Sr(OH)2- soluble
Ba(OH)2 - soluble

Question 9

equations for group 2 hydroxides

Answer 9

M(aq)2+ + 2OH-(aq) —> M(OH)2 (s)

Question 10

describe solubility in group 2 carbonates

Answer 10

all slightly soluble but gets extremely less soluble ass you go down the group

Question 11

equations for group 2 carbonates

Answer 11

M(aq)2+ + CO3(aq)2- —> MCO3 (s)

Question 12

whats the trend in thermal stability in group 2 hydroxides and carbonates

Answer 12

increases down the groups

Question 13

whats the equation for the decomposition of both group 2 hydroxide and carbonate

Answer 13

MCO3—–> MO+ CO2
M(OH)2 —->MO + H2O

Question 14

what happens going down group 7

Answer 14

• molecule radius increases(greater van der waals forces)
  -melting/boiling point increase (due to greater van der waals)
• electronegativity decreases due to atomic radius increasing
• reactivity decreases

Question 15

what observations can be made when halogens (group 7) react with sodium

Answer 15

bright orange flame. sodium ignites and white solid halide

Question 16

whats the equation for the reaction of halogen and sodium

Answer 16

2Na + X2 —–> 2NaX

Question 17

what happens to the halogens when we react them with iron

Answer 17

cl- burns and glows brightly
Br - iron wool gloes less
I- slight glow

Question 18

whats the equation of when halide reacts with silver nitrate

Answer 18

KX(aq) + AgNO3(aq) —> KNO3(aq) + AgCl(s)

Question 19

what are the colour of precipitates when the halides react with silver nitrate

Answer 19

cl - white
br - cream
i- yellow

Question 20

how do we confirm the identity

Answer 20

using dilute ammonia at first and then concentrated

Question 21

what happens to the halides as we confirm their identity

Answer 21

cl dissolves in dilute ammonia
Br only dissolves in concentrated ammonia
i is insoluble in both

Question 22

what happens when Cl- reacts with Br2 or I2

Answer 22

no reaction in both

Question 23

what happens when Br- reacts with cl2 and i2

Answer 23

Cl2 - yellow solution
I2 - no reaction

Question 24

what happens when i- reacts with Cl2 or Br2

Answer 24

Cl2- brown solution
Br 2 - brown solution

Question 25

whats the equation for the halogen displacement

Answer 25

Cl2 + 2KBr —–> 2KCl + Br2

Question 26

explain how the halogen oxidises the halide

Answer 26

halogen gains electron when it oxidises halide ion
the smaller the halogen easier it is to gain electron therefore oxidisation ability decreases down a group