End point vs equivalence point (1 Viewer)

[m_isk]

we learnt in class that there is a difference between the end point and the equivalence point of a titration, however i read in conquering that "end point is sometimes referred to as equivalence point."i remeber the teacher satin that in a titration, your end pint must match your equivalence point if u r to get valid results.. now i'm really confused!!

 

[currysauce]

From Chemistry Contexts 2:

Equivalence Point: " is the point at which chemically equivalent amounts of the acid and base have been added. This is when the ratio of moles of acid and base have been added is the same as the mole ratio of the balanced equation"

Endpoint: "the endpoint is the point at which an addedd indicator changes colour"

 

[richz]

End point is the pt when the colour changes..

Equivalence pt is the pt when the colour changes to when the colour changes again. Eg. for the titration curves. The entire vertical line the the equiv pt. The end pt would be when the vert starts..

hope that helps

 

[m_isk]

Yes very much so, thank you very much

 

[Captain pi]

Just to add:

If you will,

The end point is the practical equivalence point.
The equivalence point is the theoretical end point.

A sort of succinct, not terribly thorough way of putting it; but, I hope it becomes a mantra with which you can recall this.

 

[xiao1985]

End point is the pt when the colour changes..

i agree

Equivalence pt is the pt when the colour changes to when the colour changes again.

i disagree...

say for eg, using methyl orange (colour change around pH 3) for indicator in titration of NaOH and acetic acid...

the END pt is when colour change occurs, ie, when pH reaches 3, whereas equivalence pt is at the basic range (strong base titrating against weak acid)

i second curry sauce's comment that EQUIVALENCE pt is when u added same amount of H+ and base,

whereas END pt is when colour changes..

in titration u can only observe end pt... hence u want to make the end pt as close to equivalence pt as possible...