The Mole.

• ♫~Melody.

  2 Mar 09, 19:22

  can anybody classify how many different sections there are?

  the textbook is so messy -.-

  eg. Concentration, Relative Molecular Mass blahblah..

  thanks alot, i cant study well when everything is in a chunk D:

• skythewood

  2 Mar 09, 19:38

  no

• ♫~Melody.

  2 Mar 09, 19:53

  =(

• Mervyn>_<

  3 Mar 09, 08:45

  I guess you could google websites for the Mole concept and see if you can understand them
• UltimaOnline

  3 Mar 09, 11:05

  Or, Melody could come for my tuition. All my students invariably score very well in mole calculations, after what I put them through *evil laughter*! All my 'O' level students will be trained, to correctly answer questions like the following one within 10 mins.

   

  

   

   

   

   

   

• SBS n SMRT

  5 Mar 09, 14:53

  Originally posted by UltimaOnline:

  Or, Melody could come for my tuition. All my students invariably score very well in mole calculations, after what I put them through *evil laughter*! All my 'O' level students will be trained, to correctly answer questions like the following one within 10 mins.

   

  

   

   

   

   

   

  Is x, y , z = 0 due to the charges, and equate the molecular mass of Mg CO3 OH and n(Molecular mass of water) = 466 and find n, 

  then eqn is MgCO3OH.nH20 --> Mg(OH)2 + CO2 + H2O, cannot balance due to too lasy to work out n

  Is the answer roughly what i written???

• UltimaOnline

  5 Mar 09, 15:42

  Originally posted by SBS n SMRT:

  Is x, y , z = 0 due to the charges, and equate the molecular mass of Mg CO3 OH and n(Molecular mass of water) = 466 and find n, 

  then eqn is MgCO3OH.nH20 --> Mg(OH)2 + CO2 + H2O, cannot balance due to too lasy to work out n

  Is the answer roughly what i written???

  
  You're partially correct.

   

  Here is the full solution :

  

• UltimaOnline

  5 Mar 09, 18:29

  (Challenging) 'O' Level Qn.

  (Standard) 'A' Level Qn.

   

   

  Titanium(IV) oxide is heated in hydrogen gas to give water and a new titanium oxide, TixOy. If 1.598g of titanium(IV) oxide produced 1.438g of TixOy, what is the formula of the new oxide?

   

   

  Solution :

   

  No. of mol of Ti before redox = no. of mol of Ti after redox

  0.02  =  (1.438/(47.9x+16y)) x

  x / y  =  2 / 3

   

  Hence, formula of new oxide is Ti2O3.

• iamapebble

  5 Mar 09, 19:43

  http://www.seab.gov.sg/

  I guess you might like to try going to this website and look at what candidates should know for chemistry under the mole concept, from there you should be able to classify your stuffs better. :D