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Edexcel CHEMISTRY DOUBTS!!!!
dk bose:
i have got an urgent doubt..here it is..- A 1.0 mol dm-3 solution of rubidium chloride is made when 1 mole of rubidiun chloride is added to water.RbCl (s)+aq- Rb+(aq)+Cl-
At 298K,the enthalpy change on dissolving is +19kj mol-1.
(a)Calculate the entropy change in the system
dk bose:
i have got an urgent doubt..here it is..- A 1.0 mol dm-3 solution of rubidium chloride is made when 1 mole of rubidium chloride is added to water.RbCl (s)+aq- Rb+(aq)+Cl-
At 298K,the enthalpy change on dissolving is +19kj mol-1.
(a)Calculate the entropy change in the system
plzzzz solve this doubt and post the solutions as fast as possible...plzzz help me people!!!!!!
KJ1995:
Hello guys, i would really appreciate your help.
How should i study Unit 6B chemistry. Are there any helpful books, please post the download links.. And what practicals should i know from AS and A2 for Unit 6B
Many thanks
MKh:
--- Quote from: KJ1995 on May 01, 2012, 07:54:22 pm ---How should i study Unit 6B chemistry. Are there any helpful books, please post the download links.. And what practicals should i know from AS and A2 for Unit 6B
--- End quote ---
The Chemistry laboratory skills II exam consists of 3 sections: qualitative analysis (identfying unknown compounds), quantitative analysis (calculations, graphs etc.) and Preparation (explaining the steps in a given experimental procedure for carrying out a preparation) of organic and inorganic compounds.
Check the Practical Assessment section in the Edexcel A2 Chemistry Revision Guide which is available for download in here in SF - use the search engine to search for the download link.
You will find very helpful information in that section. From the Revison Guide, I quote:
Qualitative analysis
Chemical reactions and tests that may be included in this section include:
- Any of those listed for Unit 3 (therefore you will also have to check the qualilative analysis section of the Edexcel AS Chemistry Revision Guide which is also available for free download here in SF)
- The reactions of the transition metal ions in solution with aqueous sodium hydroxide and with aqueous ammonia both added untl in excess (see pg 81 of guide)
- Ligand exchange reactions in copper (II) complexes (pg 79 of guide)
- The redox chemistry of chromium (pg 78 of guide)
[And the list goes on. It is better if you check the Guide itself]
Quantitative analysis
At least one of the following will be included in this assessment:
- pH titration
- Following the rate of a reaction
- Potassium manganate (VII) titration
- Finding the activation energy of a reaction
Preparation
Laboratory practices needed for preparation:
- Those developed at AS, such as heating under reflux and distillation
- Purification of an impure solid product by recrystallization from hot, saturated solvent
- Melting temperature determination
- Drying solid by filtration under reduced pressure - using a Buchner funnel and flask
Do make sure that you know how to draw labelled diagrams for the apparatus used to carry out distillation, reflux, filtration under reduced pressure and the ones used to determine melting and boiling temperature of a compound
Hope this helps.
-Cornea:
is anyone over here doing AL chemistry if so i need a proof for bohr's theory of atomic structure it's not actually a proof it's the steps from where did we we get tht 109678 number ....Thanks in advance :)
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