Would you expect a difference in the mass of #"AgCl"# produced by the reaction depending on whether you used the #"1 M"# or #"0.1 M"# of #"NaCl"#? Give reasons for your answer.

There wouldn't be a difference in mass, right? would only require a greater volume of #"NaCl"#.

1 Answer
Dec 5, 2017

Answer:

Well, that depends...

Explanation:

The idea here is to always keep in mind what reactant, if any, acts as a limiting reagent,

Assuming that you're working with a double-replacement reaction reaction similar to this one

#"AgNO"_ (3(aq)) + "NaCl"_ ((aq)) -> "AgCl"_ ((s)) darr + "NaNO"_ (3(aq))#

then the concentration of the sodium chloride solution will not have an impact on the mass of silver chloride produced by the reaction if sodium chloride is in excess in both cases.

In other words, if the number of moles of silver nitrate is always smaller than the number of moles of sodium chloride, then you can add as many moles of the latter as you want because the former will always be the limiting reagent, i.e. determine how many moles of silver chloride are produced by the reaction.

So as long as you have

#"moles of AgNO"_3 " "< " ""moles of NaCl"#

it doesn't matter exactly how many moles of sodium chloride you have.

However, if you have

#"moles of AgNO"_3 " "< " ""moles of NaCl in 1-M solution"#

and

#"moles of AgNO"_3 " "> " ""moles of NaCl in 0.1-M solution"#

then in the case of the #"0.1-M"# sodium chloride solution, silver nitrate will no longer be the limiting reagent and the number of moles of sodium chloride will determine the mass of silver chloride produced by the reaction.