# Calculation of solution

1. Dec 13, 2013

### rovaniemi

I have a doubt that I would like to solve with your help.

The 1st solution I have is

10 mg/10 ml
from the above solution 1/10th is diluted that should be (0.1)
from the above 1/10th diluted solution another 1/10 is diluted again
from this once again diluted 1/10th solution 1/5 is again diluted
once again from this 1/5th diluted solution 2.5/5 is again diluted.

My question is is there any formula to calculate the decimal point. I mean 1/10th is denoted as 0.1th, but how to note multiple diluted solutions? from 1/10 to 1/10 to 1/5 to 2.5/5

2. Dec 13, 2013

### tiny-tim

hi rovaniemi!
i'm not sure what you mean

do you mean that 10 mg/10 ml is diluted to 1 mg/10 ml ?

or do you mean that 10 mg/10 ml is diluted to 9 mg/10 ml ?​

in the first case, the concentration is multiplied by 0.1

in the second case, the concentration is multiplied by 0.9

if you perform several dilutions, you multiply those factors

for example, if the concentration is multiplied once by a factor of 0.1 and once by a factor of 0.5, then the combined concentration is 0.1 times 0.5, = a factor of 0.05

3. Dec 13, 2013

### rovaniemi

Hi Tiny Tim,

Thanks for the reply. Just need to confirm what I understood it correct.

I have used the first case where 10mg/10ml is diluted to 1/10

Now it is 0.1.

If I dilute it again to 1/10 .

Then the solution is now 0.1 times 0.1 , so 0.01

Hope this is how it is?

Thank you

4. Dec 13, 2013

### tiny-tim

yup!

you just keep multiplying!