Periodic table

Question 1

Period 3 elements

Answer 1

Na: Giant metallic -metallic bonds
Mg: Giant metallic - metallic bonds
Al: Giant metallic - metallic bonds
ELECTRICAL CONDUCTORS W HIGH MP

Si: Giant mol lattice- cov bonds
SEMI ELECTRICAL CONDUCTOR W HIGH MP

P: Simple molecular- weak IMF
S:Simple molecular- Weak IMF
Cl: Simple molecular-Weak IMF
NON ELECTRICAL CONDUCTOR W LOW MP

Ar

Silicon has the highest MP

Question 2

Period 3 oxides

Answer 2

Na2O
MgO
Al2O3
Giant ionic lattices w high MP increasing down period however MgO has highest MP

SiO2
Giant molecular lattice struc w High MP

P4O10
SO3
Simple mol structure w low MP

Question 3

Why does MgO have the highest MP out of all period 3 oxides

Answer 3

higher MP than Al2O3 (a deviation of the trend of increasing mp down series of metal oxides

Al2O3 is an ionic cmpd with covalent character as Al3+ has High charge to size ratio hence distorts electron cloud size of oxygen to a great extent as it has High polarising power. Thus ionic bond weakened

Question 4

Trend -Electronegativity

Answer 4

The greater the diff in electronegativity the more likely bond is ionic
Across the period oxides and chlorides become less ionic and more covalent due to lesser difference in electronegativity with O and Cl respectively

Question 5

Period 3 chlorides

Answer 5

NaCl (s)
MgCl2 (s)
Giant ionic with high MP

AlCl3 (s)
SiCl4 (s)
PCl5 (s)
Simple molecular with lower MP

Question 6

Reactivity of period 3 oxides with water

Answer 6

Na2O
-dissolves in water to form a strongly alkaline w pH 13

MgO
-dissolves in water to form a weakly alkaline solution of pH 9

Al2O3
SiO2
- Insoluble in water pH 7

P4O10
SO3
Reacts readily with water to form an acidic solution of pH 3 and 1 respectively

Question 7

Reasoning for reactivity of period 3 oxides with water

Answer 7

Na2O
-reacts vigorously with H2O to give NaOH (strong base) dissociates to give strongly all solution

MgO
-slightly soluble in H2O prod.some OH- giving weakly alkaline solution due to strong ionic bond present in MgO

Al2O3
- strongly ionic bonds energy
SiO2
- Insoluble in water pH 7

P4O10
SO3
Reacts readily with water to form an acidic solution of pH 3 and 1 respectively