Saturday
April 30, 2016

# Homework Help: CHEMISTRY

Posted by albee on Thursday, April 29, 2010 at 1:34pm.

I used 10mL of unknown NaCl-NaBr mixture titrate with 0.10M silver nitrate solution.
10.15mL of silver nitrate solution is used.

the conc. of NaCl-NaBr mixture is 8g/dm3

I need to calculate the % composition of the NaCl-NaBr mixture.

I used the following calculation steps but i can't get the ans.

a + b = c......(1), where c is the weight of the mixture used, consisting a gram of NaCl and b gram of NaBr.

c= 8g x 10/1000 = 0.08g

no of moles of Cl react= a/58.44
no of moles of Br react= b/102.9
no of moles of Ag react=(0.1 x 10.15)/1000= total no of moles of Cl and Br react=a/58.44 + b/102.9
therefore, (0.1 x 10.15)/1000=a/58.44 + b/102.9.....(2)

values of a and b should easily be found by solving equation (1) and (2), however I am fail to do so.

What's wrong with my calculation?!?!
• CHEMISTRY - DrBob222, Thursday, April 29, 2010 at 2:05pm

See my response to your first post below. It looks the same as your procedure. If you want to post your work I will try to find the error.