Hey there!
The molar mass of magnesium is 24.305 grams.
The molar mass of an element is the same as the atomic mass of an element, but measured in grams.
It's on the periodic table underneath the element symbol.
Hope this helps!
Zn (s) -> Zn+2 (aq) + 2e-
Zn (s) with a neutral charge is oxidized and looses two electrons in the process to form ZnCl2 (aq) where Zn has a charge of 2+.
I'm going to go with Physical.
194.5 g of BCl₃ is present in 1 × 10²⁴ molecules of BCl₃.
Explanation:
In order to convert the given number of molecules of BCl₃ to grams, first we have to convert the molecules to moles.
It is known that 1 moles of any element has 6.022×10²³ molecules.
Then 1 molecule will have
moles.
So 
Thus, 1.66 moles are included in BCl₃.
Then in order to convert it from moles to grams, we have to multiply it with the molecular mass of the compound.
As it is known as 1 mole contains molecular mass of the compound.
As the molecular mass of BCl₃ will be

Mass of boron is 10.811 g and the mass of chlorine is 35.453 g.
Molar mass of BCl₃ = 10.811+(3×35.453)=117.17 g.


So, 194.5 g of BCl₃ is present in 1 × 10²⁴ molecules of BCl₃.