topics 1 -4 + 8
H bonds
bonds between a very electronegtive element and H
CH4 shape
tetrahedral, non polar, 109.5, 4 bonds
NH3
trigonal pyramidal, polar, 107, 3 bonds + 1 lone pair
H20
angular line, polar, 104.5 , 2 bonds + 2 lone pairs
BF3
trigonal planar, non polar, 120, 3 bonds
SF6
octahedral, non polar, 90, 6 bonds
CO2
straight line, non polar, 180, 2 double bonds + 4 lone pairs
ideal gas equation
pV = nRT
percentage yield
actual yield over theoretical yield
atom economy
Mr of intended product over all products produced
neutralisation
H ions and OH ions form water
acid
releases H+ ions in an aqueous solution
alkaline
releases OH- ions in an aqueous solution
salt
when an H+ ion in an acid is replaced by a metal
strong acid
an acid which fully dissasociates in an aqueous solution
relative atomic mass
the weighted mean mass of an atom of an element compared to 1/12 of an atom of C12
s - block element
the outer shell electron is in a s orbital
orbital
a space around the nucleus which can hold up to two electrons of opposite spin
d - block element
the d sub level is being filled
ionisation energy
the enrgy change when 1 mol of electrons are removed from 1 mol of gaseous atoms to form 1 mol of gaseous 1+ ions
ionic bonds
electrostatic attraction between oppositely charged ions
covalent bond
strong electrostatic bond between a shared pair of electrons and the nuclei of the atoms
isotope
an atom of an element with the same number of protons but different number of neutrons
NH4 (ammonium)
+
NO2
-
NO3
-
SO3
2-
SO4
2-
OH
-
PO4
3-
CO3
2-
Ni
2+
relative isotopic mass
the mass of an atom of an isotope compared with 1/12 of the mass of an tom of C12
dative covalent bonds
shared pair of electrons where both electrons in the bonded pair come from one of the atoms
electronegatvity
a meausure of attraction of an atom in a covalent bond to attract the shared pair of electrons
carbonate test
add HNO3 if positive it fizzes and releases CO2 = check by bubbling through limewater which then goes cloudy
SO4 test
add HNO3 then add Ba(NO3)2 if positive there is a white precipitate
halides primry test
add HNO3 then add AgNO3 if positive Cl= white Br = cream I = yellow
halides secondary test
add dilute ammonia - Cl = precipitates dissolves nothing happens to Br/I
add concentrated ammonia - Br= precipitate dissolves nothing happens to I
NH4+ test
warm with NaOH and the gas given off wil turn damp red litmus blue as the NH3 is the only alkaline gas