Gino David PHILIPPE

Reflection

"We cannot hold a torch to light another person’s path without brightening our own." – Ben Sweetland, [1].

Gino David PHILIPPE
Occupation:	Rector
Nationality:	Mauritian
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Skype address:	d.g.philippe
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Chemistry Resources

Electronic configuration

Electronic configuration : Notes for topic covered on Wednesday 17^th February 2010.

Electronic configuration : Print out version notes for topic covered on Wednesday 17^th February 2010.

You can read further by clicking here

First Ionisation Energy

First ionisation energy : Notes for topic covered on Wednesday 24^th February 2010.

First ionisation energy : Print out version notes for topic covered on Wednesday 24^th February 2010.

You can read further by clicking here

Ionic bonding

IONIC BONDING : Print out version notes for topic covered on Wednesday 2ⁿ² March 2010.

CLICK HERE to view an animation on Fajan's Rule

Covalent bonding

Table of content for covalent bonding
1.0 The notes and animations on Covalent bonding can be seen on the Covalent page

1.1 Shapes of molecules

Polar and non polar molecules

Click Here to view the notes on polar and non polar molecules

Intermolecular Forces

Click Here for the notes on intermolecular forces.

For more information on Van der Waal's and permanent dipole interactions click here
For more information on Hydrogen bondingclick here

Chemical Energetics

Click here for the notes on chemical energetics

Rate of Reaction

click here for the questions on Rate of reaction

A SIMPLE KINETICS PLAN

    Hydrogen peroxide decomposes in the presence of metal oxide catalysts to form oxygen and water according to the following equation.

              2H2O2 -->  2H2O  +  O2

You are required to plan an experiment to compare which of two metal oxides is the more effective catalyst by measuring the amount of oxygen formed during a 2 minute period immediately after a solution of hydrogen peroxide is added to a catalyst.

    (a) Determine a suitable number of moles of hydrogen peroxide to be used in the experiment. (5)

    (b) Suggest a suitable volume and concentration of hydrogen peroxide for the experiment. (3)

    (c) Outline the procedure in full, giving details of any apparatus used. (10)

    (d) Indicate any hazards or safety precautions specific to the experiment. (2)

                                                                                                            (Total 20 marks)

Organic Chemistry

Click here For the notes on Organic Chemistry

Practical Enthalpy of solution

Click here for question

Chemical Calculation

Practice Questions and for the Answers click here

Questions on Titrations from practical papers

Chemical Equilibria

Click here for questions on Kc

Click here for questions on Kp  

Click here for questions on buffer solutions

Questions NMR

Click here for questions on NMR

Notes on electrolysis

Click here for the notes on electrolysis

June 2000
Question 1

Titration of FA1 with FA2

Final burette reading/ cm3	25.75	25.25	25.25
Initial burette reading/ cm3	0.00	0.00	0.00
Volume of FA 2 used /cm3	25.75	25.25	25.25

Summary iodine liberated by 25.0 cm³ of FA 1 required 25.25 cm³ of FA2
(a) Mr of Na₂S₂O₃.5H2O = 248
Concentration of FA2 = 37.23 / 248
                                = 0.150 moldm^-3
(b) 1000 cm³ of FA2 contains = 0.150 mol S₂O₃^2-
25.25 cm³ of FA2 will contain = 0.150 / 1000 x 25.25 moles
                                              =   3.79 x 10-3 moles S₂O₃^2-
(c) According to equation

2 S₂O₃^2- + I₂ -->  S₄O₆^2- + 2I^-

2 moles S₂O₃^2- react with 1 mole I₂
3.79 x 10^-3 moles S₂O₃^2-  --> 1.895 x 10^-3 moles I₂

(d) 1000 cm³ FA1 contains 0.05 moles CrO₄^2-
25 cm³ of FA1 0.05 / 1000 x 25 moles CrO₄^2-
                    1.25 x 10-3 moles CrO₄^2-

(e) 1.25 x 10^-3 moles CrO₄^2- react with 1.895 x 10^-3 moles I₂
1 mole CrO₄^2- react with 1.895 x 10^-3 / 1.25 x 10^-3 moles I₂
= 1.52 moles I₂

Since 2I^-  --> I₂ + 2e-

Number of moles of I- = 2 x 1.52
                                = 3.04 moles
(f) Cr³⁺ ions

(g) CrO₄^2- + 8H⁺ + 3I^- -->  Cr³⁺ + 3/2  I₂ + 4H₂O