reactivity trends Flashcards
(29 cards)
explain trend in boiling point group 7
- size of atom increases
- number of electrons increases
- more London forces of attraction
- stronger intermolecular forces
- more energy required to break these
- increased down the group
trend in reactivity down group 7
- reactivity decreases
- oxidising power decreases
- atomic radius larger
- shielding greater
- less nuclear attraction
group 2 reactivity
- more reactive as you go down
- atomic radius larger
- more shielding
- nuclear attraction decreases
- less energy needed to remove electrons
Reaction of group 2 element with water
Hydroxide and hydrogen gas
Group 2 element react with acid
Salt and hydrogen
Group 2 oxide react with water
Make metal hydroxide
Most reactive metal group 2
Barium
What happens to first ionisation energy as you go down group 2
Decreases
more shielding
larger atomic radius
less nuclear attraction
How would calcium react with water instead of strontium
Less effervescence
Dissolves slower
Less soluble
Lower ph/less alkaline
Equation for fourty ionisation energy of strontium
Sr3+->Sr4+ +e-
bond enthalpy group 7
decreases as you go down so hydrolyses faster
testing reactivity
add silver nitrate and ethanol to chloroalkane, bromoalkane and iodoalkane
yellow precipitate forms first - iodide
cream second - bromide
white last - chloride
Why is it unrective
Non polar
Radical
Species with unpaired electron
Why carry out trial titration
To estimate titre
What happens if you wash Pipette with water instead of the acid given
Acid is less concentrated
Why is using low temp beneficial to environment
Less fossil fuel used
Reduces CO2 emission
Advantage and disadvantage of using msss balance instead of gas collection
Advantage : no loss of gas
Disadvantage : small loss in mass
How to obtain pure dry sample from mixture
Separating funnel ti separate organic layer from aqueous
Drying agent (anhydrous calcium chloride)
Organic layer is top layer
Distillation to purify
Another route to make metal hydroxide from metal
- Metal + water = metal hydroxide + hydrogen
- Metal + oxygen = metal oxide
Metal oxide + water = metal hydroxide
How would calcium hydroxide solution differ to strontium hydroxide
Strontium hydroxide has higher pH
What type of reaction is metal carbonate to metal oxide
Thermal decomposition
Disproportionation reaction / group 7 element equation eg
Br2 + 2KOH = KBr + KBrO + H2O
Atomic orbitals meaning
Region around nucleus that can hold up to two electrons, with opposite spins
