1.the atom and redox Flashcards
define isotopes.
Atoms of the same element (same number protons ) but with a different number of neutrons and different masses.
Define relative atomic mass
The WEIGHTED MEAN mass of ONE atom of an element compared with 1/12 the mass of an atom of carbon 12
Define relative isotopic mass
The mass of ONE atom of a specific ISOTOPE compared with 1/12 the mass of an atom of carbon 12
define 1st ionization energy
The energy required to remove ONE electron from each atom in ONE MOLE in the GASEOUS state, to form 1 move of gaseous 1+ ions.
Give a formula for the 2nd ionization energy of oxygen
O+(g) —> O2+(g) +e-
Define orbital
a region of space containing up to 2 e- (of opposite spin and of the same energy level)
WHat do we assume to use oxidation numbers?
Everything is ionically bonded, with top right being negative.
Three rules for determining oxidation number
1.A element in its normal state has O.N 0
2.Group 1 elements are +1
Group 2 elements are +2
Group 7 is usually -1
Oxygen is ‘always’ -2
Hydrogen is ‘always’ +1
3.All other are calculated from this with +7 being the highest.
Oxidation is ……
Reduction is …..
….Losing electrons
…Gaining electrons
Define oxidizing agent
An oxidizing agent causes a different species to be oxidized
Common O.A , O2 , acidified manganate, acidified dicromate, H2O2
In the reaction the O.A gets reduced.
what is a redox reaction
one where both oxidation and reduction happen
define disproportionation
The oxidation and reduction of the same element in a redox reaction.
£ factors effecting ionisation values and their effect
- Atomic radius - bigger=less IE
- No. shielding e- - More=less IE
- Nuclear charge- More=more IE
1st IE trend across a period
IE increases generally over a period.
more nuclear change -increases IE
Shielding e- says the same
Atomic radius gets slightly smaller- slightlyhigher IE
1st IE trend down a group
IE decreases down the group
more nuclear change -increases IE
more Shielding e- less IE (cancels out N.C)
Atomic radius increases- lower IE
Why is LogIE plotted?
because the range of numbers being plotted is fucking huge, and loging it making it easier to compare by making all the numbers smaller while still keeping their order.
What do you need to label in a orbital diagram?
the 90% boundary
the +
or axis if its a p orbital
Shapes of p and s orbital
S- spherical
P-Dumb-bell
Why are their two deviations in 1st IE across a group?
Due to subshells.
Eg period 2. Li,BE,B,C,N,O,F,Ne
Boron - has 4 shielding e- because it includes the 2s orbital which lowers the IE.
Oxygen-The repulsion of the paired e-s in the p orbital causes it to require less energy.
The first row of the D-block is…
3d
Why are Cr and Cu odd?
Cr has 5 e- in 3d and 1 in 4s due to a pair of e- causing 4s to have a higher energy level then 3d so one e- moves to 3d
Cu- 10 e- in 3d and 1 in 4s for the same reason
what happens (e- wise) when d block elements react?
always lose e- to become a cation
4s orbital always loses e- first.
