Answer: The molecular formula will be 
Explanation:
Molecular formula is the chemical formula which depicts the actual number of atoms of each element present in the compound.
Empirical formula is the simplest chemical formula which depicts the whole number of atoms of each element present in the compound.
The empirical formula is 
The empirical weight of
= 1(12)+3(1)= 15g.
The molecular weight = 45.0 g/mole
Now we have to calculate the molecular formula:

The molecular formula will be=
Thus molecular formula will be 
This problem is providing us with a statement in which we need to figure out the word fitting in the blank. At the end, after analyzing the information, the word turns out to be colligative as show below:
<h3>Colligative properties.</h3>
In chemistry, colligative properties of solutions account for the behavior of a solution with respect to the pure solvent, to which a solute is added.
Among them, we have boiling point elevation, freezing point depression, vapor pressure lowering and osmotic pressure, which are all affected by the concentration of the solute but not by the identity of the solute.
In such a way, we conclude that the correct word that fits in the blank is colligative as shown below:
"Colligative properties depend on the concentration of a solute in a solution but not on the identity of the solute."
Learn more about colligative properties: brainly.com/question/10323760
Both trials of 1.2 g and 1.6 g will have the same mass percent of water because the ratio of the salt to the water of hydration is always constant for any hydrated salt.
<h3>Water of hydration</h3>
For every hydrated salt, the ratio of the salt to the water of hydration remains constant irrespective of the amount of salt taken for experimental analysis.
For example, assuming the mass percent of water in 10g of a hydrated salt is 40%, if 100g of the same salt is taken, the mass percent will remain 40%.
More on water of hydration can be found here: brainly.com/question/11202174
hydrogen (H2),and oxygen (O2),, that is the answer