Group 2 Flashcards
What is metallic radius
Half the distance between nuclei in a giant metallic lattice
Describe and explain the trend in IE down group 2
IE decreases
Nuclear charge increase outweighed by sheilding effect
And distance from valence shell increasing
Describe the trend in reactivity of group 2
Reactivity increases
Ability to lose e- increases
Why are cations of group 2 smaller in radius than their atoms
Cations have one less shell
Less electrons less repulsion
Describe the trend in reducing power down group 2
Increases
Describe and explain the trend in melting points down group 1 and 2
Decreases
Size of atom increases
Decrease in metallic bond strength
Write an equation for the reaction of group 2 metals with H2O
X + H2O—-> X(OH)2 + H2
Describe observations of reaction of group 2 metals with water down the group
Reaction vigour increases down group-effervescence of H2 gas increases
Solubility of hydroxides formed increases thus pH increases more alkaline solution formed
Describe and explain the trend in solubilities of sulfates down group 2
Solubility decreases BeSO4 (aq) MgSO4 (aq) CaSO4 (s) SrSO4(s) BaSO4 (s)
Radius of cation increases charge density decreases
Lattice energy decreases
Enthalpy of hydration decreases
Decrease in enthalpy of hydration is greater
Thus enthalpy of solution becomes more endothermic
Describe and explain the trend in solubility of group 2 hydroxides and oxides
Increases down group
Be(OH)2 / Mg(OH)2 (s) insoluble
Ca(OH)2 (aq) partially soluble
Sr(OH)2/Ba(OH)2 (aq) very soluble
Both L.E and ΔHhyd decrease
Decrease in LE is greater than hydration
Enthalpy of solution becomes more exothermic
Write equation for reaction of group 2 metals with oxygen
X + 1/2O2 —–> XO
Observations when Be reacts with oxygen
Silver grey solid dissappears
White solid forms
Bright White flame
Observations when Mg reacts with oxygen
Silvery grey solid dissapears
White solid formed
Burns in white flame
Observations when Ca reacts with oxygen
Silvery grey solid dissappears
White solid formed
Burns in a brick red flame
Observations when Sr reacts with oxygen
Silvery grey solid dissappears
White solid appears
Burns in scarlett/crimson red flame