Steers Chem Flashcards
What happens to first ionisation energies down a group
Decreases
Causes of change in ionisation energy down a group
Atomic radius increases, shielding increases, nuclear attraction decreases- ionisation energy decreases
Trend in first ionisation energy across a period
Increases
Causes of trend in ionisation energy across a period
Nuclear charge increases Same shell-similar shielding Nuclear attraction increases Atomic radius decreases Ionisation energy increases
Trends down group 2
Reactivity inc
Ionisation energy dec
Solubility inc
pH inc- more alkaline down group
Why does boiling point increase down group 7
More electrons
Stronger London forces
more energy necessary to break forces
Boiling point increases
Why does reactivity decrease down group 7
Atomic radius increases
More shielding
Less nuclear attraction to attract electron to get full outer shell
Reactivity decreases
Why does reactivity increase down group 2
Atomic radius increases
Nuclear attraction decreases
Shielding increases
Less energy needed to lose electrons
G2+O2
MgO
Mg h20
Mg(oh)2 and h2
Mg hcl
Salt and water
MgO h20
Mg(oh)2
Solubility of group 2 hydroxides
Increases down group as has more OH- ions
Risks of chlorine in water
React with hydrocarbons ch4 from decaying veg to produce chlorinated hydrocarbons suspected of causing cancer
First electron affinity vs second
First=exo
2nd=endo
Why are second electron affinities endo
Second electron being gained by a negative ion which repels which needs energy to force it on
Enthalpy change of solution
The enthalpy change that takes place when one mole of solute dissolves in a solvent
(NaCl—–> Na+. Cl-
Enthalpy change of hydration
The enthalpy change that accompanies the dissolving of gaseous ions in water to form one mole of aqueous ions
Effect of ion size on lattice enthalpy
Ionic radius increases
Attraction between ions dec
Lattice energy less exothermic
Mp decreases
Smaller ions attract more easily. More energy given off
Effect of charge on lattice enthalpy
Charge increases
Ions more attraction
More negative lattice energy
Mp increases
Ions attract more easily give off more energy
Effect of ion size on hydration
Ionic radius increases
Attraction between ion and water decrease
Hydration enthalpy less -ve (increases)
Effect of ionic charge on hydration
Ionic charge increases
Attraction with water increase
Become more -ve
More energy given off
Cu2+ Fe2+ Fe3+ Mn2+ Cr3+
Add sodium hydroxide to metal sulfate Cu2+ blue ppt of caoh Fe2+ green ppt Fe3+ brown ppt Mn2+ off white ppt Cr3+ forms dark green solution
Standard entropy
Entropy of one mile of substance under standard conditions
