Yield of a reaction

[5614]

i was thinking that if you have a more concentrated acid then there are more parts acid per part water.

 

going by that surely a higher concentration would therefore produce more yield or end product. because there'd be more acid for the other reactant to react with...

 

however in a recent experiment i did i found that varying concentration varies the rate of reaction, but does not vary the total yield produced... i was wondering why that is?

[budullewraagh]

if the reactants are in the same quantity, you should have the same products. it just takes a little longer for the aqueous reactants to reach one another. when they do, they react. the more dilute a solution the more time this takes, but eventually they do reach one another.

[5614]

yeah but what im saying is that if you have x-cm3 of acid at 1 molar concentration then you do the same reaction with the same volume of acid but at 2 molar concentration then the concentration has doubled.

 

double concentration = twice as much solute (acid) and half as much solvent (water)

 

^^ is that right???

 

if so a more concentrated acid would have more acid for the other reactant to react with... if thats wrong then what is double concentration?

[budullewraagh]

oh i see what youre saying. was there a limiting reagent involved?

 

edit:

example: you (slowly) put 1mol NaOH in 1L of 1M HCl. you (slowly) put 1mol NaOH in 1L of 2M HCl.

[5614]

i started with 2M acid.... i did a reaction using that and then used 50% 2M acid and 50% water for 1M

[chemistry]

The acid is a catalyst, you should know how this applies to your question.

 

sidetrack-

 

Also, in aqueous solutions, increasing the concentration of the acid does not necessarily increase the acidity of the solution. Acids dissociate through there interactions with water, in most cases we are assuming that water is plentiful. However, when water is limiting, you can guess that there will be problems with dissociation.