Question

SiO2 + 4HF → SiF4 + 2H2O

Answer 1

Answer : The reaction requires 242 grams of HF.

Explanation : Given,

Mass of $SiO_2$ = 182 g

Molar mass of $SiO_2$ = 60 g/mole

Molar mass of HF = 20 g/mole

First we have to calculate the moles of $SiO_2$

$\text{Moles of }SiO_2=\frac{\text{Mass of }SiO_2}{\text{Molar mass of }SiO_2}=\frac{182g}{60g/mole}=3.03moles$

Now we have to calculate the moles of HF.

The given balanced chemical reaction is,

$SiO_2+4HF\rightarrow SiF_4+2H_2O$

From the balanced chemical reaction, we conclude that

As, 1 mole of $SiO_2$ react with 4 moles of HF

So, 3.03 moles of $SiO_2$ react with $4\times 3.03=12.12$ moles of HF

Now we have to calculate the mass of HF.

$\text{Mass of HF}=\text{Moles of HF}\times \text{Molar mass of HF}=12.12mole\times 20g/mole=242g$

Therefore, the reaction requires 242 grams of HF.

Answer 2

SiO2 + 4HF → SiF4 + 2H2O
60 g. --> 80 g
182 g. --> x g
$x = \frac{182 \times 80}{60} \\ x = 242.7 \: g$

The reaction requires 242.7 grams of HF.