3.2.2 Group 2 Metals

Question 1

what’s an observation when magnesium reacts with steam?

Answer 1

a white solid forms

Question 2

why’s the melting point of Mg higher than Na?

Answer 2

• Mg has more delocalised electrons
• more/stronger attraction between nucleus and delocalised electrons

Question 3

How can you distinguish between solutions of MgCl2 and AlCl3?

Answer 3

• add NaOH
• white precipitate forms in MgCl2 (Mg(OH2) is insoluble)
• precipitate dissolves in excess in the other solution

Question 4

why is the second ionisation energy of calcium lower than the second IE of potassium?

Answer 4

• more shielding in Ca+
• K loses electron from 3 orbital and Ca loses electron from higher energy orbital