SiO2 + 2C --> Si + 2CO what mass of sand(SiO2) is needed to produce 45.0 g of silicon?

Question

Hi, could someone please walk me through this, I am a little confused.
The first thing I would do is find how many moles of Silicon (Si)
so 45.0 Si * 1 mol Si/28.1 g Si = 1.60 mole Silicon.

I am stuck on what to do next!

Answer 1

You are doing fine. You know how many moles of silicon. Each SiO2 gives you 1 Si, so moles SiO2 = moles Si. All you need to do now is to multiply by the formula mass of SiO2.

You always use moles when comparing amounts of different substances. You also always need a balanced equation to get the ratio of amounts of the different substances, which in this case is simply 1:1.