Qualification > Sciences
Chemistry Help HERE ONLY !!
Ghost Of Highbury:
evaporation - a process occuring at the surface if a liquid invloving the change of state if a kiquid into vapour
at a temperature below the boiling point
crystallisation - salt is obtained from sea water on vast scale through crystallisation, this is done by using the heat of the sun to evaporate the water to leave a saturated solution of salt. after saturation, the salt begins to crystallise. it is actually heating followed by quick cooling.
Shogun:
--- Quote from: Nanavel on May 30, 2009, 03:47:48 pm ---how do you know what is the suitable reagents for certain reactions ??
If they ask me do describe the structure of Diamond >>> I can either say : " It has tetrahydral shap with four carbon atoms convalently bonded to other four carbon forming a gaint marcomolecular shap "
OR
" It has tetrahydral structure with four oxygen atoms covalently bonded with a single atom of Silion forming a gaint marcomolecular shap "
--- End quote ---
tht u have to mug up the reactions' reagent or use common sense, cuz its just impossible to tell which reagent to use or which reagent is for which reactions, in this post cuz thier are a million ef em and differnt type of it use different rreagents, so to solve tese problem, understand the concept of making salts and the concept of testing alcohols and alkenes and cations and anions, understand tht concept, for eg: how they from precipitate, why they change colour, etc. tht way u will know which reagent to use and when.
and the structure, use the first one, seems to be more acceptable and easy, appropriate.
oh yea evaporation can happen at any temperature at surface of liqiud, not as boiling point which occurs at a fixed temp called boiling point.
Shogun:
adi, how do i put pics on posts...
Ghost Of Highbury:
u gotta click on reply --> additional options--> attach --> choose file -- attach the image --> post
the image will also appear with the attachment
:)
SGVaibhav:
--- Quote from: ADi...M on May 30, 2009, 03:37:54 pm ---plz find it attached
Mg ? Mg2+ + 2 e-
S + 2e- ? S2-[
--- End quote ---
THANKS A LOT
yeaahhh
but i got one more question ::)
Bromine reacts with phosphorus to form phosphorus tribromide.
Draw a diagram showing the arrangement of the valency electrons in one molecule of
this covalent compound. The electron distribution of bromine is:
2 + 8 + 18 + 7.
Use x to represent an electron from phosphorus.
Use o to represent an electron from bromine.
very ??? over here
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