Question

just doing this to check that my answers are right

Answer 1

2. To calculate the number of grams in 3 moles of Mg, we need to do the conversion from moles to grams using the molar mass of Mg that you can find in the periodic table (24.31 g/mol). The conversion will be:

$3\text{ moles Mg}\cdot\frac{24.31\text{ g Mg}}{1\text{ mol Mg}}=72.93\text{ g Mg.}$

We have 72.93 g of Mg in 3 moles of them.