[cremeegg]

Hi all,

This is my first question on this site and I am really confused and struggling.

Last week I did a titration with 0.1 M HCl in the burette and Na2CO3 diluted in water (1,4473g) in the beaker.

I did 3 titrations and discovered that it took on average 28.5ml of HCl to neutralise the Na2CO3.

After the lab we had to do some calculations and this is where I am stuck…. The question says:

If the average titre is v mL, and the (still unknown) conc/n of HCl is X mol L-1, then the amount of HCl added is;
v/1000 x X mol

The amount of Na2CO3 in each titration is mass Na2CO3 in each flask/RMM Na2CO3

So

X =2000 x mass/v x RMM

Complete the cal of the conc of HCl expressing the measured conc as the average conc plus or minus the range.

------------------

I inputted my figures in and got 0.92 mol L-1 but now I have NO idea what to do regarding this range average and measured concentration.  Does anyone have any idea what this means??

I would REALLY appreciate some help, thankyou

 

[FeLiXe]

you did three titrations so you have three values

giving the range means giving the largest and smallest value (or the difference between them)

[natrium]

the most logical thing you can do... calculate the average conc with the 3 values and later compare it with the max and min values of that concentration

I hope this can be useful