1) Check if the chemical equation is balanced.
[tex]\text{SiO}_2+4HF\rightarrow SiF_4+2H_2O[/tex]
2) Convert grams of SiO2 into moles
[tex]molesofSiO_2=182gSiO_2\cdot\frac{1moleofSiO_2}{60.0843gSiO_2}=3.0291[/tex]
3) How many moles of HF reacts
[tex]\text{molesofHF}=3.0291molesofSiO_2\cdot\frac{4\text{molesofHF}}{1moleofSiO_2}=12.1163[/tex]
4) Convert moles of HF into grams
[tex]\text{gramsofHF}=12.1163\text{molesofHF}\cdot\frac{20.0063\text{gof HF}}{1\text{moleofHF}}=242.4025\text{ g of HF}[/tex]
The reaction requires 242 grams of HF
