chem exam q: identify reagent

Describe how a student could distinguish between aqueous solutions of magnesium chloride, MgCl2, and aluminium chloride, AlCl3, using one simple test-tube reaction.

Answer:
- NaOH / sodium hydroxide / other Group 1 hydroxides
- white precipitate / white solid
- (white) ppt which dissolves in excess (NaOH)

Alternative Method
- Name or formula of Group 1 carbonate
- white precipitate / white solid
- (white) precipitate and effervescence

I dont understand how u would come to this answer; which topic does this fall into that I'm missing? thank youu

Reply 1

Pigster

Original post by Ra_Ar

Describe how a student could distinguish between aqueous solutions of magnesium chloride, MgCl2, and aluminium chloride, AlCl3, using one simple test-tube reaction.
Answer:
- NaOH / sodium hydroxide / other Group 1 hydroxides
- white precipitate / white solid
- (white) ppt which dissolves in excess (NaOH)
Alternative Method
- Name or formula of Group 1 carbonate
- white precipitate / white solid
- (white) precipitate and effervescence
I dont understand how u would come to this answer; which topic does this fall into that I'm missing? thank youu

GCSE or A level? Exam board?

Reply 2

Ra_Ar

Original post by Pigster

GCSE or A level? Exam board?

a level aqa

Reply 3

Pigster

Original post by Ra_Ar

a level aqa

Loosely it is in here: 3.2.6 Reactions of ions in aqueous solution (A-level only)
Some metal hydroxides show amphoteric character by dissolving in both acids and bases (eg hydroxides of Al³⁺)

Reply 4