How many moles of hydrogen are in the sample?
Round your answer to 4 significant digits.

1.56 mol H₂

Explanation:

Mg₃(Si₂O₅)₂(OH)₂

There are 4 Si moles per Mg₃(Si₂O₅)₂(OH)₂ mol. With that in mind we can calculate how many Mg₃(Si₂O₅)₂(OH)₂ moles are there in the sample, using the given number of silicon moles:

3.120 mol Si * = 0.78 mol Mg₃(Si₂O₅)₂(OH)₂

Then we can convert Mg₃(Si₂O₅)₂(OH)₂ moles into hydrogen moles, keeping in mind that there are 2 hydrogen moles per Mg₃(Si₂O₅)₂(OH)₂ mol:

0.78 mol Mg₃(Si₂O₅)₂(OH)₂ * 2 = 1.56 mol H₂

Aphysical change is one that you can put in and remove like a ham sandwich. the stuff you put in there can be changem its not permanet. a chemical change is on that can't be change thats permanet. like when you make a cake and bake it. you can't get those ingredients back.

The teacher is mostly talking about the distillation of a mixture