Period 3 Oxides

Question 1

which period 3 elements react with water

Answer 1

• sodium and magnesium

Question 2

what is the equation, observation and product of the reaction of sodium with water

Answer 2

• 2Na (s) + 2H₂O (l) → 2NaOH (aq) + H₂ (g)
• effervescence
• colourless solution with pH 12-14 (alkaline)

Question 3

what is the equation, observation and product of the reaction of magnesium with cold water

Answer 3

• Mg (s) + 2H₂O (l) → 2Mg(OH)₂ (s) + H₂ (g)
• white ppt
• alkaline solution (pH 8-9)

Question 4

what is the equation, observation and product of the reaction of magnesium with steam

Answer 4

• Mg (s) + H₂O (g) → MgO (s) + H₂ (g)
• white flame
• basic solid

Question 5

what is the equation and observation of the reaction of sodium with oxygen

Answer 5

• 2Na (s) + 1/2O₂ (g) → Na₂O (s)
• yellow flame and yellow solid

Question 6

what is the equation and observation of the reaction of magnesium with oxygen

Answer 6

• Mg (s) + 1/2O₂ (g) → MgO (s)
• white flame and white solid

Question 7

what is the equation and observation of the reaction of Aluminium with oxygen

Answer 7

• 2Al (s) + 3/2O₂ (g) → Al₂O₃ (s)
• slow reaction

Question 8

what is the equation and observation of the reaction of Silicon with oxygen

Answer 8

• Si (s) + O₂ (g) → SiO₂ (s) (silica)
• slow reaction

Question 9

what is the equation and observation of the reaction of Phosphorus with oxygen

Answer 9

• P₄ (s) + 5O₂ (g) → P₄O₁₀ (s)
• white smoke and white flame

Question 10

what is the equation and observation of the reaction of sulfur with oxygen

Answer 10

• S (s) + O₂ (g) → SO₂ (g) (silica)
• blue flame, choking gas

Question 11

what is the bond angle in SO₂

Answer 11

• 117.5

Question 12

which of the period 3 oxides act as bases

Answer 12

• the metals
• Na₂O, MgO, Al₂O₃

Question 13

which of the period 3 oxides act as an acid

Answer 13

• the non-metals
• SiO₂ , P₄O₁₀ , SO₂ , SO₃, Al₂O₃

Question 14

which period 3 oxide can act as both an acid and a base

Answer 14

Al₂O₃

Question 15

what period oxides do not react with water

Answer 15

• SiO₂
• Al₂O₃

Question 16

what is the equation for the reaction of sodium oxide with water

Answer 16

• Na₂O (s) + H₂O (l) → 2NaOH (aq) (pH 12-14)

Question 17

what is the equation for the reaction of magnesium oxide with water

Answer 17

MgO (s) + H₂O (l) → Mg(OH)₂ (aq) (pH 8-9)

Question 18

what is the equation for the reaction of phosphorous pentoxide with water

Answer 18

• P₄O₁₀ + 6H₂O (l) → 4H₃PO₄ (aq) (pH 1)

Question 19

what is the equation for the reaction of sulfur dioxide with water

Answer 19

• SO₂ (s) + H₂O (l) → H₂SO₃ (aq) (pH 1)
• H₂SO₃ = sulfurus/sulfuric (IV) acid

Question 20

what is the equation for the reaction of sulfur trioxide with water

Answer 20

• SO₃ (s) + H₂O (l) → H₂SO₄ (aq) (pH 0)

Question 21

what is the structure of H₃PO₄ when dissolved in water and how many protons does it lose

Answer 21

• 3

Question 22

what is the structure of H₂SO₃ in water and how many protons does it lose

Answer 22

• 2

Question 23

what is the structure of H₂SO₄ in water and how many protons does it lose

Answer 23

• 2

Question 24

what is the equation for the reaction of Al₂O₃ with an alkali

Answer 24

• Al₂O₃ (s) + 2NaOH + 3H₂O (l) → 2NaAl(OH)₄

Question 25

what is the equation for the reaction between solid sodium oxide and phosphorous pentoxide

Answer 25

- P₄O₁₀ (s) + Na₂O (s) → 4Na₃PO₄

Question 26

what is the equation for the reaction between solid magnesium oxide and phosphorous pentoxide

Answer 26

- MgO (s) + P₄O₁₀ (s) → 2Mg₃(PO₄)₂ (s)