Unit 2 Group 2

Question 1

What is the equation for the reaction of magnesium with water

Answer 1

Mg(s) + H2O –> MgO(s) + H2(g)

Question 2

What is the reaction of calcium and cold water

Answer 2

Ca(s) + H2O(l) –> Ca(OH)2 + H2

Question 3

All group 2 metals oxidise in air. Write an equation for this

Answer 3

2Mg + O2 –> 2MgO

Question 4

What is the solubility of sulphates going down group 2 and give a use of barium sulphate

Answer 4

The solubility of sulphates decreases going down the group. Barium sulphate is used in medical practice as “barium meal” and is used in X-Ray’s for surveying the esophagus stomach and small bowel

Question 5

What’s the solubility of hydroxides going down group 2 and give a use for magnesium hydroxide

Answer 5

The solubility of hydroxides increases going down the group as the metal reacts more readily with water. Magnesium hydroxides is used as an antacid for excess stomach acid, the alkaline solution neutralises excess HCl acid

Question 6

describe the reactivity of group 2 metals going down the group

Answer 6

The metals get more reactive going down the group, this is because of the increase in ease to lose the two electrons in the outer S orbital!

This is due to shielding from inner electron shells, the electrostatic forces acting upon the outer electrons is “felt less”