Group 2 Flashcards
Describe and explain the trend, down the group, of the reactivity of Group 2 with water. (5)
- reactivity increases
- atomic radii increases
- more shielding
- increased nuclear charge
- ionisation energy decreases
Why are the second ionisation energies of calcium and strontium greater than their first ionisation energies? (1)
- ion is smaller
Explain why barium is more reactive than calcium. (4)
- Barium atoms are larger
^ more shielding - outweighs the increase in nuclear charge
- ionisation energy decreases
Which Group 2 oxide produces a saturated solution with the highest pH?
BaO(aq)
State how a Group 2 element forms an ionic bond with non-metals.
- by donating its 2 outer electrons
Are group 2 elements oxidising or reducing agents?
reducing.
Explain the trend in first ionisation energies as you move down Group 2. (4)
- decreases
- nuclear charge same
- shielding increases
^ leads to weaker attraction between the nucleus & the outermost electrons
Describe the trend in alkalinity as you move down Group 2. (1)
- increases
Describe the trend in the reactions of Group 2 with water. (1)
- react more vigorously w/ water as you go down the group
Explain the trend in the first three ionisation energies of magnesium. (3)
- ionisation energy increases
- similar shielding
- large increase b/w 2nd and 3rd IE because 3rd electron is being removed from 2p orbital rather than 3s orbital
Explain how the trend in solubility and strength as a base observed going down Group 2 are connected. (3)
- solubility in water & strength as a base both increase down the Group
- increasing solubility means that there’s more OH- ions in the solution
- base strength is measured by the concentration of OH- ions.
Explain how the bonding in Beryllium Chloride differs from the rest of the Group 2 Chlorides. (4)
- predominantly covalent
- Be2+ = highest mass-charge ratio
- so Be2+ polarises the Cl ion
- causing the Cl ion to share its electron
Give the reagents required to test for and distinguish between the halide ions. (4)
- dilute nitric acid
- silver nitrate solution
- dilute ammonia
- concentrated ammonia
Define: disproportionation reaction
- a reaction in which the same species is simultaneously oxidised and reduced.
Suggest why adding chlorine to the drinking water is safe to do so. (2)
- it’s only added in small volumes
- therefore not harmful to humans in those levels