Ask Experts Questions for FREE Help!
 

Free Answers in 3 Easy Steps

Register Now
3 Steps
 


Ask QuestionsprogressAnswer QuestionsprogressBuild ReputationprogressBecome an Expert
 
At Ask Me Help Desk you can ask questions in any topic and have them answered for free by our experts. To ask questions or participate in answering them you must register for a free account. By registering you will be able to:
  • Get free answers from experts in any of our 300+ topics.
  • Accept money for answers that you provide.
  • Communicate privately with other members (PM).
  • See fewer ads.
  Answer this question    Ask about Math & Sciences    Ask about another Subject  
 

hayzemay
Oct 17, 2007, 02:56 AM
KCl (1.4720 g) was made up to 250 cm3 solution. 25 cm3 reequired 21.13 cm3 AgNO3 for titration

KCl + AgNO3 ŕ AgCl + KNO3


what is the molarity of AgNO3

templelane
Oct 17, 2007, 03:14 AM
The question has two parts:-
Forst you need to work out the molarity of KCl
Use this equation

Amount (moles) = mass (grams) x volume (litres)

Remember to change the units of the volume form cm^3 to l


Second part knowing how many moles of KCL you can work out the moles of AgNO3
Take note that you only need a tenth of the initial soultion molarity you worked out
The equation shows the ratio of KCL:AGNO3 is 1:1

So if KCl works out ot be 10M (it's not) then you use 1M to react with 21.13 cm^3

25/21.13 = 1.18

1M /1.18 = 0.85M of AgNO3

Does that make sense?

If not I'll explain it a different way. In fact this website explains it differently but very nicely (they use less steps than me) Titration Calculations (http://www.webchem.net/notes/Periodicity/titration_calcs.htm)

hayzemay
Oct 17, 2007, 03:16 AM
thanks ever so much