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CHEM AND BIO HELP AND TIPS HERE

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nid404:

--- Quote from: Ari Ben Canaan on January 15, 2010, 10:40:06 am ---Could some one tell me if my answers are correct to the following question.

Thanks !

PS: its in the attached doc file !

--- End quote ---

The mass of BaCO3 is incorrect
Ba=137
C=12
O=16X3
=197g

moles of BaCO3 that reacted would be 0.005(1:1 ratio)
Mass of BaCO3(pure) would be 0.005X197=0.985g
%purity=0.985/1.23 X100
=80.08%

:)

holtadit:
Thanks again Nid !!!

I messed up on calculating the mass of BaCO3 . I thought C was 12 and O was 16

:D Silly mistake ! Anyways thanks for helping !

+rep

holtadit:
QUESTION
Draw diagram 1 to show the arrangement of silicon atoms around one carbon
atom in silicon carbide. Label this diagram 1.

Draw diagram 2 to show the arrangement of carbon atoms around one silicon
atom in silicon carbide. Label this diagram 2.

ANSWER
diagram 1 four silicons around one carbon
diagram 2 four carbons around one silicon

-------------------------------------------------------------------------------------

I dont understand how this is so... the formula of Silicon Carbide is SiC with the ratio of Si:C being 4:4 hence 1:1.

How do u get the answer.... PLZ explain the UNDERLYING chemistry behind this question. What is is that u need to know to do these questions.

nid404:
Silicon nd Carbon are both group 6 elements...valency four.
This should help u analyse the diagram.....to form an octet...they will share 4 electrons
if u still don't get it....ill explain it

saleemsamer:
hey guys i have searched for what i wanted on this site but haven't found wat i need
i need notes for genetic engineering, population size and human influence on the ecosystem.
they are self study topics and i want to make sure that i understand.
plz post any type of notes with these topics and thx in advance

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