reaction of group 3 oxides

Question 1

write an equation for the reaction of sodium with water

Answer 1

Na (s) + H2O (aq) —> NaOH (aq) + 1/2 H2 (g)

Question 2

describe what is observed when sodium reacts with water

Answer 2

Na floats
Fizzes due to H2 production
Moves around on surface of water

Question 3

write an equation for the reaction of magnesium with steam

Answer 3

Mg (s) + H20 (g) —> MgO (s) + H2 (g)

Question 4

describe what is observed when magnesium reacts with water

Answer 4

Mg burns with a bright white light
white solid formed

Question 5

write an equation of the reaction of Na with Oxygen

Answer 5

2Na (s) + 1/2 O2 (g) —-> Na2O (s)

Question 6

describe what is observed when sodium reacts with oxygen

Answer 6

Na burns with a yellow/orange flame, white solid produced

Question 7

write an equation for the reaction of Mg with oxygen

Answer 7

Mg (s) + 1/2 O2 (g) —-> MgO (s)

Question 8

describe what is observed when Mg reacts with oxygen

Answer 8

Mg burns with bright white flame
white solid produced

Question 9

write an equation for the reaction of Al with oxygen

Answer 9

4Al (s) + 3O2 (g) —-> 2Al2O3 (s)

Question 10

describe what is observed when Al reacts with oxygen

Answer 10

Al burns with a white flame
white solid produced

Question 11

write an equation for the reaction of Si with oxygen

Answer 11

Si (s) + O2 (g) —> SiO2 (g)

Question 12

describe what is observed when Si reacts with oxygen

Answer 12

Si burns with a white flame
Grey solid is formed

Question 13

write an equation for the reaction of P with oxygen

Answer 13

P4 (s) + 5O2 (g) —> P4O10 (s)

Question 14

describe what is observed when P reacts with oxygen

Answer 14

P burns with a white flame
white solid formed

Question 15

write an equation for the reaction of S with oxygen

Answer 15

S8 (s) + 8O2 (g) —> 8SO2 (g)

Question 16

describe what is observed when S reacts with oxygen

Answer 16

S burns with a blue flame
gaseous SO2 formed which turns UI red

Question 17

explain how to produce SO3

Answer 17

react SO2 with O2 with V2O5 catalyst

Question 18

state the type of bonding in the period 3 oxides

Answer 18

Na2O, MgO, Al2O3 - ionic
SiO2 - giant covalent
P4O10, SO2, SO3 - van der waals (simple molecular)

Question 19

write an equation for the reaction of Na2O with water, state the pH of the solution formed

Answer 19

Na2O + 2H2O –> 2NaOH

pH 14

Question 20

write an equation for the reaction of MgO with water, state the pH of the solution formed

Answer 20

MgO + H20 –> Mg (OH)2

pH 10

Question 21

explain why MgO produces a less basic solution than Na2O

Answer 21

Mg (OH)2 is sparingly soluble in water, much lower OH - ion concentration

Question 22

explain why Al2O3 does not react with water

Answer 22

the lattice is too strong to break

Question 23

explain why SiO2 does not react with water

Answer 23

the lattice is too strong to break

Question 24

write an equation for the reaction of P4O10 with water, state the pH of the solution formed

Answer 24

P4O10 + 6H2O —> 12H+ + 4PO4 3-

pH 1-2

Question 25

write an equation for the reaction of SO2 + water, state the pH of the solution formed

Answer 25

SO2 + H20 —> 2H+ + SO3 2-

pH 1-2

Question 26

write an equation for the reaction of SO3 with water, state the pH of the solution formed

Answer 26

SO3 + H20 —> 2H+ + SO4 2-

pH 1-2

Question 27

explain why basic oxides form alkaline solutions
and give the equation for the reaction

Answer 27

have free O2- ions that react with water to produce OH- ions

O2- + H2O —> 2OH-

Question 28

what does amphoteric mean

Answer 28

when dissolved in water it can react as an acid or a base

Question 29

which period oxide is amphoteric

Answer 29

Al2O3

Question 30

write an equation for the reaction of Al2O3 with HCl

Answer 30

Al2O3 + 6HCl —> 2AlCl3 + 3H2O

Question 31

write an equation for the reaction of Al2O3 with NaOH

Answer 31

Al2O3 + 2NaOH + 3H2O —> 2NaAl (OH)4