Group 2 elements

Question 1

atomic radius _ down group 2

because:

Answer 1

increases

energy level added and hence weaker force of attraction felt

Question 2

metallic radius is measure of

Answer 2

size

Question 3

melting point _ down group 2

and why

Answer 3

decreases 
delocalised electrons (in their own energy level) are further away from nucleus and strength of metallic bond decreases

Question 4

density _ down group 2

why?

Answer 4

increases Generally

as atomic radius increases so do mass and volume but mass at greater rate which is proportional to density

Question 5

how do group 2 elements react

Answer 5

lose 2 electrons from S-orbital

Question 6

group 2 reactivity _ down the group

why?

Answer 6

increases
there is greater shielding effect and distance because of increased energy levels hence easier to remove outer shell electron

Question 7

ionisation energy _ down the group

Answer 7

decreases

Question 8

group 2 metals burn in oxygen to form _ which is _ in nature

Answer 8

white solid oxide

basic (dissolve to form hydroxide)

Question 9

reactivity of metals with water down the group _ and forms _

Answer 9

increases

metal hydroxide

Question 10

metals react with steam to form

Answer 10

metal oxide and H2 gas

Question 11

use of calcium oxide

Answer 11

used to neutralise acid in soil

Question 12

why beryllium is not an alkali earth metal

Answer 12

amphoteric rather than alkaline behvaior of compounds

Question 13

reactivity with oxygen _ down group

Answer 13

increases

Question 14

barium stored in oil because

Answer 14

rapidly vigourously reacts with O2 in air

Question 15

flame test of Ca, Sr, Ba, Mg compounds

Answer 15

Burn in O2:
Ca- brick red color
Sr- red
Ba- light green 
Mg- white

Question 16

How metals burn at atomic level

Answer 16

metal loses 2e- and donates to O

Question 17

alkalinity _ down group because ..

Answer 17

increases

cos solubility increases down group: more soluble=more dissociation/able to donate more OH-

Question 18

alkalinity _ down group because …

Answer 18

increases
cos solubility of hydroxides increases down group: more soluble=more dissociation/able to donate more OH-

white ppt (as not transition) or sol

Question 19

solubility of hydroxides and sulfates(why for this) _ down

Answer 19

hydroxide- inc
sulfates- dec bcos lattice energy and enthalpy change of hydration decrease hence applying hess law the value of enthalpy chnage of solution becomes more endothermic

Question 20

carbonates of grp 2 are _ in water

Answer 20

insol

Question 21

carbnotes react with dil acid to give

Answer 21

salt+h2o+co2

Question 22

which grp 2 sulfates (formed from reacting with dil h2so4) are sol and insol

Answer 22

mgso4-sol

rest-insol

Question 23

grp 2 nitrate salts are _ in water

Answer 23

all soluble

Question 24

thermal decomposition of grp 2 carbonates

Answer 24

give off metal oxide + co2

Question 25

thermal decomposition of grp 2 nitrates

Answer 25

metal oxide + no2 + o2

Question 26

temperature of thermal decomposition _ down grp

Answer 26

increases

Question 27

stability of nitrates _ down group hence _ temp required

Answer 27

increases

higher

Question 28

uses of CaCO3, Ca(OH)2

Answer 28

CaCO3- rocks for building, marble for tiles, cement making

Ca(OH)2- neutralize soil aka slaked lime

Question 29

cement making:

Answer 29

high temp of kiln CaCO3 decomposes to CaO+CO2 and the quick lime is roasted with clay to make cement
-cement can be mixed with sand to increase strength

Question 30

why does solubility of sulfates decrease down group

Answer 30

1) larger the cation, weaker lattice so lattice energy decreases as becomes less endo
2) weaker cations bond with water less exo so E change of hydration decreases

hence E of sol becomes more endothermic hence more difficult to dissolve
so 1 has mor value than 2 relatively because 1 decreases less compared to 2

Question 31

process of hydroxides dissolving

Answer 31

ionic lattice breaks as ions dislodge as water attracts ions. this process is endo to break ionic bonds
then new bonds between ions and polar water are formed