period 3 oxides

Question 1

equation for magnesium with cold water and features of the product

Answer 1

magnesium + water –> magnesium hydroxide + hydrogen gas
-slow reaction
-pH of around 10 as magnesium hydroxide is relatively soluble

Question 2

what is the equation for sodium with oxygen and observations

Answer 2

sodium + oxygen –> sodium oxide
-yellow flame and white precipitate

Question 3

equation for the reaction of magnesium with steam

Answer 3

magnesium + steam –> magnesium oxide + hydrogen gas

Question 4

observations for reaction of magnesium with oxygen

Answer 4

-bright white light
-white precipitate

Question 5

reaction for aluminium with cold water

Answer 5

no reaction

Question 6

reaction of aluminium with oxygen

Answer 6

bright white light, forms white powder

Question 7

why is aluminium considered unreactive even though the metal itself is reactive

Answer 7

-aluminum oxide covers the surface of the aluminium
-aluminium oxide is unreactive, which makes it useful for saucepans or window frames

Question 8

properties of silicon

Answer 8

-semimetal (metalloid)
-semiconductor (conducts electricity in certain conditions and to a certain extent)

Question 9

reaction of silicon with oxygen and the observation

Answer 9

silicon + oxygen –> silicon dioxide
-white precipitate formed

Question 10

features and properties of phosphorus

Answer 10

-non-metal with a low boiling point and melting point, doesn’t conduct electricity
-red phosphorus exists as crystal structure whilst white phosphorus exists as P4

Question 11

reaction of phosphorus with excess oxygen

Answer 11

-red phosphorus needs to be heated first, while white phosphorus ignites spontaneously in air
-forms white crystalline solid of phosphorus pentoxide

Question 12

reaction of phosphorus with limited oxygen

Answer 12

-incomplete combustion, colourless liquid
-phosphorus trioxide is formed

Question 13

reaction of sulfur with oxygen

Answer 13

heat first and then react
-burns with a blue flame
-produces sulfur dioxide (and SOME sulfur trioxide)

Question 14

what are the types of bonding displayed by the period 3 oxides

Answer 14

-Na, Mg and Al exist as ionic crystals (ionic lattice)
-Aluminium ion is polarising and causes distortion of electron clouds = covalent character
-Si exists as macromolecular crystal (giant covalent)
-P and S exist as simple molecular crystals

Question 15

what period 3 oxides are basic

Answer 15

-sodium oxide and magnesium oxide

Question 16

what is the property of aluminium oxide

Answer 16

-amphoteric (can act as a base or an acid)

Question 17

is aluminum oxide soluble

Answer 17

not in water

Question 18

is silicon dioxide soluble in water

Answer 18

no

Question 19

in what condition will silicon dioxide act as an acid

Answer 19

-reacts as a weak acid with a strong base i.e NaOH but hot and conc.

Question 20

what is a use of MgO

Answer 20

additive in cattle feeding