Answer: Bubbles, burning, odor, color change, and rusting.
Explanation: Chemical changes are changes to something that is irreversible.
Molar mass of MgCO3 is 84.313 g/mol
You can calculate this from data on the periodic table:
Molar mass Mg = 24.305g/mol
molar mass C = 12.011g/mol
molar mass O = 15.999g/mol mass 3 mol = 47.997g
Total = 84.313g/mol
Mass to be used in 1.2L of 1.5M solution = 84.313g * 1.2L * 1.5mol /L = 151.763g
I have not taken significant figures into account
The balanced equation you provide is not necessary in this calculation
The cloudiness of the eyes increases to a maximum and then decreases. This is because initially, after death, all the muscles relax, dilating the pupil. Some time later, rigor mortis sets in, contracting the pupil. Thus, the cloudiness fades.
Answer: 
is the limiting reagent
Explanation:
To calculate the moles :
The balanced chemical reaction is :
According to stoichiometry :
1 moles of require = 2 moles of 
Thus 0.625 moles of will require=
of
Thus is the limiting reagent as it limits the formation of product and is the excess reagent as it is present more than the required amount.
