Answer:
43.93 g/mol
Explanation:
The mass of the gas before reaction = 52.1487 g
The mass of the gas after reaction = 52.1098 g
Mass of gas generated = 0.0389 g
Moles of the gas = 
The formula for the calculation of moles is shown below:

Thus,


Molar mass of the gas = 43.93 g/mol
So calculate the H for the other two reactions a room temperature and combine the reactions to calculate the H of the decomposition of calcium carbonate using the Hess's Law
<u>Answer:</u> The unbalanced chemical equation is written below.
<u>Explanation:</u>
Unbalanced chemical equation does not follow law of conservation of mass.
In an unbalanced chemical equation, total number of individual atoms on the reactant side will not be equal to the total number of individual atoms on the product side.
The chemical equation for the reaction of diboron trioxide and magnesium metal follows:

Hence, the unbalanced chemical equation is written above.