Question

Fine the moles in 15.9 grams of SiO2

Answer 1

.265 mol

Step-by-step explanation:

We want to find the number of moles in 15.9 grams of SiO2

First we need to find the molar mass of SiO2

Looking at a periodic table 1 atom of Si has a mass of 28.086g

And 1 atom of oxygen has a mass of 15.999g

So the molar mass of SiO2 would be 28.086(1) + 15.999(2) = 60.084g/mol

Now we can use dimensional analysis to find the number of moles in 15.9 grams of SiO2

Setting up the table we get

`\frac{15.9gSiO_2}{} *(1 molSiO_2)/(60.084gSiO_2)`

the g SiO2 cancels out and we get

`\frac{15.9}{} *(1 molSiO_2)/(60.084)`

we then evaluate 15.9 * 1/60.084 to get .265 mol

So there are .265 moles in 15.9 grams of SiO2