Question

SiO2 + 4HF → SiF4 + 2H2O

In this chemical reaction, how many grams of HF are needed for 182 grams of SiO2 to react completely? Express your answer to three significant figures.

The reaction requires__ grams of HF.

Answer 1

SiO2 + 4HF → SiF4 + 2H2O
60 g. --> 80 g
182 g. --> x g

`x = (182 * 80)/(60) \\ x = 242.7 \: g`

The reaction requires 242.7 grams of HF.

Answer 2

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}=(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* 3.03=12.12` moles of HF

Now we have to calculate the mass of HF.

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

Therefore, the reaction requires 242 grams of HF.