# Question #7b9b5

##### 1 Answer

#### Answer:

21.31 g of HF

#### Explanation:

To solve this question, one must use Moles to calculate the masses of the different compounds.

First we must determine the molecular weight of

MW=molecular weight

MW

MW

The mass of O should be multiplied by factor two since you have 2 oxygen atoms in

Then we proceed to calculate the number of moles of the reactant

We have got 16.0 gram of

We now look at the mole ratio between

To get the amount of moles that will react with 0.266... moles of

The question asks us to calculate the mass of HF that will react with

Finally, we must give the answer in the appropriate amount of significant digits (the lowest one given has 4 significant digits):

21.31 g of HF

And that's it! Try to calculate it by yourself again so you get the drill!

For future calculations ALWAYS determine the moles! Most of the questions can be solved that way.