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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: redXI on August 23, 2005, 09:51:36 AM

Title: Balancing...(completely confused)
Post by: redXI on August 23, 2005, 09:51:36 AM

I must be really bad at chemistry, I can't even do these questions...

1. __P + __O2 ---> __P4O10

Answer: 4P+5O2=P4O10

2. __Fe(OH)3 ---> __Fe2O3 + __H2O

3. __Na2CO3 + __ Ca(OH)2 ---> __NaOH + __CaCO3

I can only do number one. As for the rest, I'm completely blank  :-X
I need help, in a few days, a big test is waiting to eat me up but I won't lose! That's why. Thanks.

Title: Re:Balancing...(completely confused)
Post by: sdekivit on August 23, 2005, 11:11:40 AM

Fe(OH)3 --> Fe2O3 + H2O

Fe is balanced by taking 2 Fe(OH)3.

then look at H and O at their ratios

Now we have 6 O on the left thus we nee 3 O's from water --> 3 H2O. Now H becomes 6 and is balanced:

2 Fe(OH)3 --> Fe2O3 + 3 H2O

Now try the last one.

Title: Re:Balancing...(completely confused)
Post by: redXI on August 24, 2005, 06:08:47 AM

__Na2CO3 + __ Ca(OH)2 ---> __NaOH + __CaCO3

answer:
Na2CO3+Ca(OH)2 --- > 2NaOH + CaCO3

Title: Re:Balancing...(completely confused)
Post by: xiankai on August 24, 2005, 06:16:33 AM

u got it correct, good work.

Title: Re:Balancing...(completely confused)
Post by: madknt on August 24, 2005, 11:31:40 PM

this site will help you if you get stuck.. wont help in a test though ;)
http://www.sunncity.com/Calculator/Chemcal/Cal.html