Someone please check this urgently

[Asterix]

Given a 20% w/v solution of Chlorhexidine Gluconate, what volume is required to make the following solutions.

2 litres of a 0.2%

I did C1V1 = C2V2

So: 20V1= 0.2*2000

so v1= 0.2*2000/ ( 20) = 20ml.

However my friend says that the 0.2 has to be divided by 100 before you do anything. Help please!

[johnep]

Re: Someone please check this urgently

I agree with you.

2,000 mls of 0.2%

equals 200mls of 2%

equals 20mls of 20%

johnep

[Asterix]

Re: Someone please check this urgently

I agree with you.

2,000 mls of 0.2%

equals 200mls of 2%

equals 20mls of 20%

johnep

so my method is right yeah? if it says 1% you would just go with 1% right, not do 1/100 first yeah?

[johnep]

Re: Someone please check this urgently

1% is 1/100.

You should have done conversion of fractions to decimals at junior school.
johnep