4 - Inorganic Chemistry and the Periodic Table Flashcards
How do group 2 metals react with oxygen?
-usually forms a metal oxide (MO)
-strontium will form a peroxide (MO₂) if heated under high pressure
-barium will too if heated under standard pressure (forms mixtures of barium oxide and peroxide)
How do group 2 metals react with water?
forms metal hydroxide and hydrogen (apart from beryllium, too unreactive)
How do group 2 oxides react with water?
forms metal hydroxide
How do group 2 oxides react with dilute acids?
-neutralisation reaction (as they are basic)
-forms salt and water
BeO can act both as a base and an acid (amphoteric),but it will still form a salt and water
Describe the different reactions seen from halide ions with sulfuric acid going down the group:
-all of them will form a hydrogen sulfate and a hydrogen halide first
-the thermal stability of the hydrogen halides decreases down the group
-each hydrogen halide reacts with the sulfuric acid again and forms one of the other products that show their reducing power (plus the halogen and water)
Explain why the reactions of solid iodide and chloride compounds with sulfuric acid form different products:
iodide ions are better reducing agents than chloride ions, because it can lose electrons more easily
How do you test for ammonium ions?
-add NaOH and gently warm
-forms ammonia gas which is basic, so hold damp red litmus paper over the sample and it will turn blue
What colour do magnesium ions give in a flame test?
no colour observed
Only elemental magnesium gives the intense white
Why do you dip the nichrome wire into concentrated HCl first?
it reacts with the unknown compounds to produce more volatile chlorides
It also can be used to clean off any residue from previous tests
How does heated magnesium react with steam?
When asked to describe what you might see in a reaction involving a metal, what could you say?
Other than bubbling
metal disappears
This is usually accepted
