DN 6). Perid 3 And Group 2 Flashcards Preview

Chemistry > DN 6). Perid 3 And Group 2 > Flashcards

Flashcards in DN 6). Perid 3 And Group 2 Deck (27):
1

Atomic radius across a period ....

Decreases

2

Why does Atomic radius across a period

Nuclear charge increases
Outer electrons in same energy level
Same shielding
So attraction of electrons increase
Atomic radius decreases

3

First ionisation across a period ...

Increases

4

Why does First ionisation across a period

Nuclear charge increases
Outer electrons in same energy level same shielding and distance
Therefore more attraction

5

Graph shape of first ionisation energy across a period

Up 2
Down
Up 3
Down
Up 3

6

Melting point across a period

First 3 = metallic binding so as u go along the positive ion charge increases and more electrons in sea of delocalised electrons
Then spike as Si = macromolecular covalent
Then van dear waals = P4 , S8, Cl2, Ar

7

Atomic radius as you go down group 2

Increases

8

Why does atomic radius increase as you go down group 2

Outer electrons I a new energy level each time

9

First ionisation energy down group 2 explained

Despite increase in nuclear charge
Outer electrons further from nucleus
More shielding
First ionisation decreases

10

First ionisation energy down group 2

Decreases

11

Melting point as you go down group 2

Decreases

12

Why does melting point decrease down group 2

Metallic bonding
Nuclear charge always 2+
Electrons in sea of delocalised electrons further from nucleus
So weaker attraction so lowers

13

Reactivity if group 2

As down group reactivity increases

14

Measuring reactivity down group 2

Metal + 2 water --> m(OH)2 + hydrogen
White precipitate
More bubbles

15

Magnesium plus steam

Mg + H2O --> MgO + H2

16

Mg(OH)2

Milk of magnesium for indigestion

17

Ca(OH)2

Limewater as solution
Slaked lime as solid which reduces soil acidity

18

Ca and CaO

Flue gas disulphurisation

19

Flue gas disulphurisation equation

SO2 + 0.5 O2 + water ---> H2SO4

20

Solubility if group 2 hydroxides

Get more soluble down

21

Group 2 sulphate so solubility

Get less soluble

22

Test for sulphites

Dilute HNO3
Barium chloride
White precipitate forms

23

Use for barium sulphate and a property

Barium meals for X-rays
It is insoluble

24

How to extract titanium

TiO2 + 2Cl2 +2C ----> TiCl4 + 2CO
At 900 degrees
TiCl4 + 2Mg ----> Ti + 2MgCl2
At 500 degrees
Completed in an argon at,ops here to stop TiO2 reforming

25

Test OH IONS

Litmus paper blue

26

Nh3 or nh 4+

Sodium hydroxide
Warm
Litmus blue

27

Co3 2minus test

HCL
Bubbles turn limewater cloudy