[mehc]

In a rock sample, the content of % CaO is 50 %. I have to convert it to  % CaCO3.

For this purpose, percent CaO must be converted to grams of CaO, then through moles, grams CaCO3 can be calculated. Is this point right?

How can I convert percent to grams? I do not know the weight of sample taken etc. the only known value is % CaO.

Thanks

[Arkcon]

When faced like a problem like this, a trick I use (or crutch, if you will) is to just select an arbitrary mass.  Like 1g, or 2g, or 10g.  After all, with percent in and percent out, the mass shouldn't matter.  You can confirm it by using each mass to see if you get the same answer.

[mehc]

I have tried as 50 % CaO aquals to 50 g CaO in 100 g rock.

Are you saying the same point?

[Hunter2]

Yes that is what he is saying. Now convert the 50 g into mole and backward to gram for the carbonate.

[mehc]

Ok. Thanks a lot.

[billnotgatez]

@mehc
What did you get as your final answer?

[mehc]

My result is 89.28 percent or 89.28 g calcium carbonate in 100 g,

[billnotgatez]

I got about 89% as well
I wonder what are the significant digits.