CHEMISTRY-----STICHIOMETRY

[mas5ara]

CAN ANY1 PLEASE POST ANY IMP FORMULAS OR WAYS IN REMEMBRING HOW TO SOLVE THESE QUESTIONS SPECIALLY THE EXCESS ND LIMITIMNG PART IN ADDITION TO THE PERCENTAGE YEILD ND PURITY
IT JUST SUCKS :S :S

 

[SuperXDE]

Check the notes mentioned in this post.

Check this , hope it helps

 

[mas5ara]

ok..... bt don't u hav any specified notes for stichiometry

 

[SuperXDE]

I don't really get what you are seeking to be honest.

 

[mas5ara]

actually...... i hav serious problems in understanding anythng in stichiometry so i need sth simple nd easy to memorize nd learn be4 the exam

 

[SuperXDE]

Umm... Stiochemistry is just about Equations? in other words ... a balanced Equation ... what is an Equation? Formulas ? Word equations? and the extended part of it is Mole and its calculations which are based on 2 rules , Mole = Conc × Volume , Mass = Mole × Relative Mass ( Either Atomic or Molecular ) ... ¬¬ Want my advice... answer the most recent 4 year papers.

 

[mas5ara]

thnx........

 

[SuperXDE]

thnx........

أي خدمة

 

[mas5ara]

btw.... wats ur name nd in wat skool r u in

 

[XPFMember]

let me give some general details:
-Define mole:1 mole of any substance is its Ar or Mr expressed in grams
-no. of moles = mass of substance/mass of one mole
-no. of moles of gas = volume in dm3 /24 (1dm3=1000cm3_
-no. of moles of solute= conc. X volume (be careful in units either all dm3 or cm3)
-(u shud know how to rearrange an eqn.)
-when the reaction involve only gases then we can use the ratio of volumes instead of mole ratio.
-Percentage yield = actual yield/theoritical yield X100
-Percentage purity = mass of pure substance / mass of impure substance X 100
-steps forfinding molecular formula
---find no. of moles(method of finding this differs according to question)
---hence find the mole ratio
---and then calculate emperical formula
---find n which is=>relative molecular mass/emperical formula mass
---then find molecular formula=>(emperical formula)n and simplify
-finally what SuperXDE said practice some past paper question as Practice makes a man perfect!!

 

[mas5ara]

thnx math angel really appreciate

 

[SuperXDE]

btw.... wats ur name nd in wat skool r u in

My name is Sherif Azmy , and I do not attend a school , Self-study student.

 

[niassu]

but if ur living in Egypt ebaa lazem tekoon fi madrasa 2lshan homa mabesma7osh bel private stuednts that what i know sherif

 

[SuperXDE]

but if ur living in Egypt ebaa lazem tekoon fi madrasa 2lshan homa mabesma7osh bel private stuednts that what i know sherif

I am living in Qatar Attending via the British Council in Qatar , I was in Port Said Language school in Egypt 2 years ago.