[schuheric]

Hello,

I have a simple question. I am trying to make a 3% chlorine solution. What would be the equivalent ppm of that solution? 30,000ppm no?

Thanks

[billnotgatez]

I did GOOGLE on

convert percent to ppm

[AWK]

Yes, the conversion factor from % to ppm is 10⁴.

[pcm81]

The problem with % to ppm conversions is that % content is not a unique measure, while ppm is very specific. For example, vodka is 40% by volume ethanol, which is not the same as 40% by mass and it is not the same as 400,000ppm.
PPM is very specific since it is molecular fraction, hence the molar mass is irrelevant or accounted for. The percent composition can be by mass, by volume or by molar fraction...

[chenbeier]

ppm is defined as 1 part per 1 million.

So it could be 1 mg per 1 kg in case of mass.  But as already mentioned also if Volume is meant   
1 μl per 1 liter.

In case of the chlorine solution its difficult, because a gas is dissolved in water. The percentage is also not correct. So need to have the mass of the chlorine in mass solution.

[Borek]

ppm is very specific

Sadly, it is not. It can be mass parts (most common) but it can also be volume, atoms per atoms, or mg per L (whatever the mass of the L is). It is generally not better than %.