Chapter 8: Reactivity Trends Flashcards
Group 2 and Halogens
What are group 2 elements sometimes called?
Alkaline Earth Metals
How to group 2 elements act in redox?
Group 2 elements are oxidised meaning that they themselves are reducing agents
What is the trend in reactivity of group 2 elements?
Reactivity increases down the group
What is the redox reaction of a group 2 element with an acid?
Metal (G2) + Acid → Salt + Hydrogen
What is the trend in first ionisation energy of group 2 elements?
First ionisation energy reduces down the group. Meaning that these higher mass elements more readily react.
What reaction occurs when Group 2 oxides react with water?
-Addition
-ΧO + H₂O → Χ²⁺ + 2OH⁻
⇒Ca(OH)₂ in excess
How soluble are group 2 hydroxides?
Generally only slightly soluble and readily precipitate out of solution when formed.
What is the trend in the solubility of group 2 hydroxides and how can this be tested?
Solubility increases down the group.
Test by producing a g2 hydroxide saturated solution of water and test for alkalinity. The more alkaline the greater number of hydroxide ions in solution the lower in g2 the element.
What are the uses of group 2 compounds?
-bases: neutralise acidic soil
neutralise stomach acid
What are the appearances of observed halides at RTP?
Fluorine- pale yellow gas
Chlorine- pale green gas
Bromine- red/brown liquid
Iodine- shiney, grey/black solid
What is the trend in b.p of halides?
B.p increases down the group
How do halides usually behave in redox reactions?
Act as oxidising agents as they themselves are reduced.
What are the trends in the displacement of halides?
More reactive halides will displace less reactive halides. Eg chlorine will displace iodine.
What trends are present in halides?
Atomic radius and shielding increases down the group.
Reactivity decreases down the group.
What is a disproportionation reaction?
A reaction where the same element is both reduced and oxide.
