chemistry paper 1 Flashcards
Reactivity down group
New shell added so outer electrons further from nucleus
More shielding
So first ionisation energy decrease and reactivity increases
Colour of iodine
Solid-grey/black
Gas-purple
why shape
no of bond
no of lone
move to minimise replulstion
bond lone > bond bond
polar based on polarity of bond
if no of bonds is even not polar
if odd polar as reinforce dipole
how to write isotopes formulas
postive charge
may be multiple for each number
e.g
34 17+17 or 16+18
decomposition temp
polarising power
larger radius polarises the bond less
so the bond of ion in common is stronger e.g nitrate
so more energy required to overcome bond
how to draw ligands
from lone pairs to middle
feasability in correlation to entrophy
more moles on the right of the equation
so entropy is positive
gibbs equation
conjugate base/acid
base
-proton acceptor - gains H+
-becomes more positive
acid
-proton donor - looses H+
-becomes more negative
salt bridge chemical
KNO3
KCl
how is max temp rise measured
extrapolation to orgional temp to line of best fit vertically up
how is rate of decompositon of metal carbonates measured
bubble through lime water and measure time to go cloudy
when conc of H+ = OH- what is the solution ph
neutral
high or low Ka
Strong acids have high Ka values. The higher the Ka, the more the acid dissociates
how to use curve to find Ka
half the eqivolence
10^-ph/10^-pka
metalic bonding
strong electrostatic forces of attraction between a lattice of positively charged cations and a sea of delocalised electrons
1s ionisation energy
energy required to overcome the bonds when one mole of gaseous atoms loses one mole of electrons to form one mole of gaseous 1+ ions
assumtion for Ka
H+ = OH-
dissasociation is neglible
why are theroeticla and experimental lattice values similar and not
similar -nearly 100% ionic
not similar- covalent character so polarises the bond
what is enthlapy change
heat change at a constant pressure
mass of the particles
proton + neutron - 1
electron - 1/1840
why would something decompose even if not feasable
not standard conditions
not 1 moldm-3c
not 298 k
100 kpa
how do sol act as buffers
contain a large amount of carbonate
ions and hydrogencarbonate ions
carbonate ions react with added hydrogen ions
hydrogencarbonate ions react with added hydroxide ions
