chem help

[Dean713]

can some1 plz explain how to find %yield n plz give an example?...

 

[Nibz]

-(Percentage Yield is actually used to calculate the PERCENTAGE of a product produced COMPARED to the amount you would expect to be produced based on the amount of reactants you started with)

The basic formula for this is- ACTUAL YIELD/Theoretical Yield *100 (actual yield divided by theoretical yield and multiply by 100)
Example:
-Mg(s) + 2HCl(aq) ==> MgCl2(aq) + H2(g)
-Atomic masses : Mg = 24 and Cl = 35.5, and formula mass MgCl2 = 24 + (2 x 35.5) = 95
(a) What is the maximum theoretical mass of magnesium chloride which can be made from 12g of magnesium?
sol:Reacting mass ratio calculation from the balanced equation: 1 Mg ==> 1 MgCl2, so 24g ==> 95g or 12g ==> 47.5g MgCl2

(b) If only 47.0g of purified magnesium chloride was obtained after crystallising the salt from the solution, what is the % yield of the salt preparation?
sol: % yield = actual amount obtained x 100 / maximum theoretical amount possible
-% yield = 47.0 x 100 / 47.5 = 98.9%

 

[amritbagga]

can someone please attach their chemistry notes of 0620 .i am going to give paper 32 on 11th please.......

 

[Nibz]

These might help :|

Use these as a quick revision tool before entering the Examination Hall

 

[Dracula95]

These might help :|

Use these as a quick revision tool before entering the Examination Hall

Oh thanks!....xtremely useful....why the :| though.. :mrgreen:

 

[Nibz]

Cuz I thought it was too late :|

P.S u cud have thanked me by clicking the "Thank" option