# Calculating the percentage of silica

1. Jul 26, 2012

### xiphoid

1. The problem statement, all variables and given/known data
A partially dried clay mineral contains 8% of water, the original sample contained 12% water and 45% silica. Then, the percentage of silica in the partially dried sample is nearly?

2. Relevant equations
Don't know if this is would help in the calculation,
in the original sample, 12% water is present, hence non water components are consisting of 88%

3. The attempt at a solution
Attempted one but was out of range of the concept to be used.

2. Jul 26, 2012

### tiny-tim

hi xiphoid!

hint: suppose the original sample was 100 g (12 g water, 45 g silica, 43 g other stuff)

3. Jul 27, 2012

### xiphoid

I had that stuff in my mind but couldn't manage to calculate further

4. Jul 27, 2012

### tiny-tim

ok, after the sample has dried, the water is less but everything else is the same

so call it x g water, 45 g silica, 43 g other stuff, …

from the question, what equation can you find for x ?