test 3. redox, grp 2 and grp 7

Question 1

what is the oxidation state of an element?

Answer 1

0

Question 2

oxidation state of group 1

Answer 2

+1

Question 3

oxidation state of group 2

Answer 3

+2

Question 4

oxidation state of oxygen

Answer 4

-2

Question 5

oxidation state of oxygen in F20 and Peroxides

Answer 5

F2O= +2

Peroxides = -1

Question 6

oxidation state of hydrogen

Answer 6

+1

Question 7

oxidation state of hydrogen in METAL hydroxides

Answer 7

-1

Question 8

oxidation state of flourine

Answer 8

-1

Question 9

oxidation state of group 7

Answer 9

-1

Question 10

oxidation in terms of electrons

Answer 10

loss of electrons

Question 11

reduction in terms of electrons

Answer 11

gain of electrons

Question 12

oxidation in terms of oxidation state

Answer 12

increase in oxidation state
e.g (0 to +2)

Question 13

reduction in terms of oxidation state

Answer 13

reduction in oxidation state (0 to -2)

Question 14

a general equation for a typical redox reaction

Answer 14

metal+ acid -> salt+ hydrogen

Question 15

what is calcium hydroxide

Answer 15

lime water

Question 16

hydroxide general equation

Answer 16

oxide(s) + water(l) → hydroxide(aq)

Question 17

what causes an increase in ph (not spec friendly)

Answer 17

more hydroxide ions, OH–, dissociate into a solution cause the pH to increase

Question 18

trend in solubility of group 2

Answer 18

• increase solubility down the grp
  -higher ph/ becomes more alkaline
  -coz more OH- released
  -so there is a higher conc. of oh- ions present.

Question 19

barium oxide and water equation

(BARIUM CAN BE SWAPPED WITH LITERALLY ANY GRP 2 METAL)

Answer 19

BaO(s) + H₂O(l) →Ba(OH)₂ (aq)

Question 20

another name for group 2

Answer 20

alkaline earth metals.

Question 21

what are the uses for group 2 Compounds

Answer 21

• Indigestion treatments
• agriculture

Question 22

what grp 2 compounds are used in agriculture and why

Answer 22

calcium hydroxide Ca(OH)₂

to increase the Ph of the soil and make it more alkali

equation Ca(OH)₂ + H₂SO₄ → CaSO₄ + 2H₂O

Question 23

what grp 2 compounds are used in indigestion treatment

Answer 23

CaCO3 EQUATION: CaCO₃ + 2HCl → CaCl₂ + H2O + CO₂

and

Mg(OH)₂ EQUATION: Mg(OH)₂ + 2HCl → MgCl₂ + 2H₂O +

Question 24

why are group 2 metals s block elements

(why is nay element in any block)

Answer 24

the highest energy electron is in an s sub shell

Question 25

what is the trend in reactivity of group 2 and why

Answer 25

-the reactivity of grp 2 increases DOWN a period -and become more powerful reducing agents -because the outer shell electron is lost more easily COZ -sum of 1st and 2nd ionisation energy decrease down the grp -nuclear attraction decreases - coz larger atomic radius means greater electron sheilding

Question 26

what are the 3 redox reactiions of grp 2 that I need to know?

Answer 26

grp 2 with oxygen water acids

Question 27

general equation for grp 2 and oxygen

Answer 27

2M(s) + O₂(g) → 2MO(s)

Question 28

general equation for grp 2 and water

Answer 28

M(s) + 2H₂O(l) → M(OH)₂ (aq) + H₂

Question 29

general word equation for grp 2 and acids

Answer 29

metal + acid → salt(aq) + hydrogen(g)

Question 30

what shell do all halogens end in

Answer 30

(s2 or p5)

Question 31

what is the grp 7 trend in boiling point

Answer 31

- boiling point increases down the group -more electrons -more London forces between molecules - more energy needed to overcome

Question 32

what is the grp 7 trend in reactivity

Answer 32

- decrease down a grp - weaker oxidising power -increased number of electrons -more shielding -larger atomic radius -weaker nuclear attraction -harder to gain electrons

Question 33

Observations in aqueous solution

Question 34

Observations with an organic solvent

Question 35

what are the 3 displacement reactions I need to know

Answer 35

Cl and Br Cl and I Br and I

Question 36

what are the 3 displacement reactions Ionic I need to know

Answer 36

1) Cl₂ (aq) + 2Br-(aq) → 2Cl- (aq) + Br₂ (aq) 2) Cl₂ (aq) + 2I-(aq) → 2Cl- (aq) + I₂ (aq) 3) Br₂ (aq) + 2I-(aq) → 2Br- (aq) + I₂ (aq)

Question 37

what is disproportionation

Answer 37

when the same element is oxidised and reduced

Question 38

what example of a disproportionation do i need to learn

Answer 38

chlorine with COLD aqueous sodium hydroxide Cl₂(aq)+ 2NaOH(aq) → NaCl(aq)+ NaClO(aq) + H₂O (l)

Question 39

NaClO(aq) household name

Answer 39

bleach

Question 40

bleach chemical formula

Answer 40

NaClO(aq)

Question 41

halides with silver nitrate general ionic equation

Answer 41

Ag+ (aq) + X-(aq) → AgX(s)

Question 42

what precipitates form with silver nitrate chlorine bromine and iodine

Answer 42

AgCl = white AgBr= cream AgI yellow

Question 43

further testing with amonia results

Answer 43

AgCl = redisolves in dilute amonia AgBr= redissolves in concentrated amonia soloution AgI+ does not redisolve