Group 2 QP

Question 1

Why is the melting point of Mg higher than Na? [2]

Answer 1

[1] Mg2+ ions are smaller

[2] Stronger attraction to delocalised sea of electrons

Question 2

What is viewed when NaOH is added to MgCl2? [1]

Answer 2

[1] White ppt

Question 3

What is viewed when NaOH is added to MgCl2? [1]

Answer 3

[1] No reaction

Question 4

Why are there different observations when barium chloride (aq) is added separately to magnesium sulphate (aq) and magnesium nitrate (aq)? What is the simplest ionic equation? [2]

Answer 4

[1] Barium sulfate is insoluble, barium nitrate is soluble

[2] Ba2+ (aq) + SO42- (aq) –> BaSO4 (s)

Question 5

What is the equation for the reaction of MgOH with HCl? [1]

Answer 5

[1] Mg(OH)2 + 2HCl –> 2H2O + MgCl2

Question 6

Why don’t you put out water should not be used to put out burning magnesium metal? [2]

Answer 6

[1] Produces hydrogen

[2] Hydrogen is highly flammable