3.2.4- Properties of Period 3 elements and their oxides (PAPER 1)

Question 1

What is the difference in reactivity between sodium and magnesium?

Answer 1

Sodium (Group 1) is more reactive than magnesium (Group 2), the amount of energy required to remove an electron from sodium is lower than to remove 2 from magnesium- more energy for magnesium to react.

Question 2

How does sodium react with cold water?

Answer 2

Vigorously, forming a ball and fizzing.

H2 gas produced, alkaline solution of NaOH

Question 3

Equation for reaction between sodium and water?

Answer 3

2Na (s) + 2H2O (l) —-> 2NaOH (aq) + H2 (g)

Question 4

How does magnesium react with cold water?

Answer 4

Slowly, forms weak alkaline solution (Mg(OH)2), magnesium hydroxide sparingly soluble so little OH- ions in solution.

Question 5

Equation for magnesium and cold water?

Answer 5

Mg(s) + 2H2O (l) —–> Mg (OH)2 (aq) + H2(g)

Question 6

How does magnesium react with steam?

Answer 6

Much faster to produce magnesium oxide

Question 7

Equation for magnesium and steam?

Answer 7

Mg(s) + H2O (g) —-> MgO (s) + H2 (g)

Question 8

How does sodium react with oxygen + equation?

Answer 8

Very fast

2Na (s) + 1/2O2 (g) —-> 2Na2O (s)

Question 9

How does magnesium react with oxygen + equation?

Answer 9

Very fast

Mg (s) + 1/2O2 (g) —–> MgO (s)

Question 9

How does aluminium react with oxygen + equation?

Answer 9

Slow, fast if powdered

2Al(s) + 1/2O2 (g) —-> Al2O3(s)

Question 10

How does phosphorous react with oxygen + equation?

Answer 10

Spontaneously combusts

P4(s) + 5O2(g) —-> P4O10(s)

Question 11

How does silicon react with oxygen + equation?

Answer 11

Slow

Si(s) + O2(g) —-> SiO2(s)

Question 12

How does sulphur react with oxygen + equation?

Answer 12

Steadily burns

S(s) + O2(g) —-> SO2(g)