Transcript Chemistry Revision 3 - Trinity School, Nottingham

Chemistry Revision
3
Electronic configurations
State which block in the periodic table you
find the following elements:
 Sulphur
 Vanadium
 Strontium

Electronic configurations
Sulphur = p
 Vanadium = d
 Strontium = s
 Write the full electronic configurations of
the following elements (in terms of 1s2 etc)
 Chlorine (17e), Cobalt (27e), Copper (29e)

Electronic configurations
Chlorine
 1s2 2s2 2p6 3s2 3p5
 Cobalt
 1s2 2s2 2p6 3s2 3p6 3d7 4s2
 Copper
 1s2 2s2 2p6 3s2 3p6 3d10 4s1
 Note this is an exception along with
CHROMIUM

Group 7 Chemistry

Complete the
following table
Halogen
Fluorine
Chlorine
Bromine
Iodine
Colour at State at
298K
298K
More on group 7
What do I see if I add sodium bromide
solution to a solution of silver nitrate?
 Write the IONIC equation for this reaction,
including state symbols.

The answerA cream precipitate would form on mixing
the two colourless solutions.
 Ag+ (aq) + Br- (aq)  AgBr (s)
 Remember that an ionic equation does
not include spectator ions!!

Oxidation numbers

Identify oxidation
numbers in the
following, and thus
deduce whether it is
oxidation or reduction
or neither!
Start
End
Br2
KBr
KMnO4 Mn2+
AgNO3 AgI
Fe2+
Fe3+
NH3
NO2
Ox?
red?
And the answers
Start
Br2
0
End
KBr
-1
Reduction
KMnO4 +7
Mn2+
+2
Reduction
AgNO3 +1
AgI
+1
Neither
Fe2+
+2
Fe3+
+3
Oxidation
NH3
-3
NO2
+4
Oxidation
Half equations
Write the overall equation and the two half
equations for the reactions occurring when
chlorine water is added to potassium
iodide solution
 Identify what has been reduced.

Half equations
Cl2 (aq) + 2I- (aq)  2Cl- (aq) + I2 (aq)
 Reduced: Cl2 (aq) + 2e-  2Cl- (aq)
 Oxidised: 2I- (aq)
 2e- + I2 (aq)
 Remember half equations do as they saythey show what is happening in half the
equation!

Economic importance of Cl + Br
Give 2 uses of chlorine or its compounds
 Give 2 uses of bromine or its compounds


Remember you are expected to know the
redox chemistry of the extraction of
bromine from sea water.
Ionic Lattices

Draw a labelled diagram to show the
structure of an ionic lattice, as exemplified
by sodium chloride
Solution calculations
It takes 12.30cm3 of 0.05M NaOH to
neutralise 25.00cm3 of HCl.
 1) Write the balanced chemical equation
 2) Work out the number of moles of NaOH
used
 3) Work out the concentration of HCl

Now try the exam q.
More next week.
 Remember- I am here to help and supportBUT I can’t do the work for you.
 Are you “striving for the best of yourself
always”??
