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Chemistry Forums for Students => Physical Chemistry Forum => Topic started by: curiouscat on April 21, 2015, 04:47:29 AM

Title: Conc. in solutions
Post by: curiouscat on April 21, 2015, 04:47:29 AM
When someone says he has a solution containing 0.1 M NaCl & 0.1 M KBr does it equivalently mean the solution could be described as containing 0.1 M KCl & 0.1 M NaBr?

i.e. In solutions is the conc. of the ions themselves the only canonical description?


Title: Re: Conc. in solutions
Post by: Dan on April 21, 2015, 06:04:55 AM
Yes, they would be identical. I suppose the way it is written refers to the actual salts used to make up the solution.
Title: Re: Conc. in solutions
Post by: Corribus on April 21, 2015, 10:13:43 AM
When someone says he has a solution containing 0.1 M NaCl & 0.1 M KBr does it equivalently mean the solution could be described as containing 0.1 M KCl & 0.1 M NaBr?
Although it is generally understood what this means, it's technically incorrect - you actually have no (or very little) NaCl or KBr (or KCl or NaBr) in solution. What you have is 0.1 M K+, 0.1 M Cl-, etc. But this would be linguistically cumbersome. So, I think your equivalence holds, at least as far as conventional semantics goes. Obviously this becomes more problematic for salts with limited solubility, e.g., AgCl instead of NaCl.