Topic 4.1.3 - Group 2 oxides and hydroxides Flashcards
What is a basic oxide?
Oxides that can react with water to form alkalis.
What happens to the solubility of group 2 hydroxides as you descend the group?
It increases.
Therefore maximum alkalinity also increases.
What is formed when a group 2 oxide or hydroxide reacts with acids?
A salt and water
Properties of all group 2 nitrates and chlorides?
They are soluble
What happens to the solubility of group 2 sulfates as you descend the group?
Solubility decreases.
Why is barium used in a test for sulfates?
Barium sulfate is produced which is insoluble and so forms a white precipitate.
How to test for sulfates in sodium sulfate?
Add dilute nitric acid and barium chloride
White precipitate is formed.
Why is dilute nitric acid or HCl added in a test for sulfates?
To remove carbonates.
Prevents barium carbonate forming a white precipitate which is a false positive test.
Why is lime added to soil?
calcium carbonate neutralises excess acidity in the soil.
