[pinkturtle]

ok i have carried out a few titrations but i have never fully understood the process of making a standard solution
my titration iam going to carry out is a strong acid weak base so iam using methly orange indicator

all i know is
i have a acidic solution of ABOUT 2.0M
i have the ratio of 1mole Na2CO3:2moles HCl
i have figured the mases out to be 106g of Na2CO3 and 73g of HCl
obviousley i am filling the burette with the acid of the unknown concentration
how do i figure out how much Na2CO3 (s) i need to make up my standard solution ?
 

[Borek]

Assume your HCl solution is 2M. For best precision you will need to use about 80% volume of your burette. Calculate how much Na₂CO₃ will react with this amount of acid. Weight precisely approximately that amount.

Are you sure you are asked to use 2M solution as a titrant? Sounds like very concentrated to me.

[pinkturtle]

well what it is is that iam trying to find out the mass of HCl acid contained in a 500ml bottle of limescale remover

does it sound ok now ?

[pinkturtle]

my mistake its 0.2 M
sorry!!

[Albert]

i have figured the mases out to be 106g of Na2CO3 and 73g of HCl
obviousley i am filling the burette with the acid of the unknown concentration
how do i figure out how much Na2CO3 (s) i need to make up my standard solution ?
 

I'm a bit confused, too. Would you be so kind as to post only the information you were given?

[pinkturtle]

ok
i have to find the mass of HCl contained in a 500ml bottle of limescale remover, the conc is thought to be about 2.0M
iam given a solution containing the limescale remover that has been diluted by 10x
iam provided with solid anhydrous sodium carbonate
thats all the info i have been given
sorry for the confusion

but i tried to workout the reacting mases (which i think are correct) and i worked out a 2:1 ratio  

[Albert]

To sum up, in your burette, there is an about 0.1N solution:

2 mmoles : 1000 mL = x mmol : 500 mL

If you have a 25mL burette, you should use 20 mL. In a nutshell, you have to titrate 2 meq (equivalents, you know what they are, don't you?).

Na2CO3 + 2HCl -> 2 NaCl + H2O + CO2

2 meq are more or less 0.1060 g of Na2CO3.

[pinkturtle]

im sorry iam only at A/S level , im finding chemistry tricky but enjoy a challenge
if u would be so kind to explain what a meq is and how u came about getting them or i u can suggest a more simple explaination to my problem
your help is greatfully recieved thanz!!!

[Albert]

http://en.wikipedia.org/wiki/Equivalent_weight

To quote, again, Wikipedia: "The normality of a solution is equal to the number of gram equivalent weights of a solute per liter of solution. The only concentration unit that is reaction dependent."

[Borek]

http://www.chembuddy.com/?left=concentration&right=normality