[green-goblin]

Hi,

Bit of an embarrassing question but my brain is not working today.

I know you can dilute an acid solution down to a desired concentration by adding water, the volume of which depends on the equation C1V1=C2V2.  But how do I increase a 0.3 M acid solution to a wanted higher concentration by adding 5M HCl. What equation do I use?

Cheers

[AWK]

The same, but expanded
c1V1 + c2V2 = c3V3

[green-goblin]

The same, but expanded
c1V1 + c2V2 = c3V3

Ok cheers.

But how do I use that to calculate the minimum Volume of the stronger C2 i can add to C1V1 and still get my desired C3.

What it is is that I have a solution of 3 weight % sample in 0.1 M HCl. I now realise that i needed this to be 3 wt% in a 0.3 M sample.  I want to add the minimum amount (so my wt % doesn't change too much) of 5 M HCl that I can to get the required 0.3 M solution.


Thanks.

[Borek]

Solve for the volume you need, this is simple equation with one unknown. One, as you may assume you start with known V1 (be it 100 mL for example).