Answer:
* 
* 
* 
Explanation:
Hello,
In this case, for the mole fraction of methanol we use the formula:

Thus, we compute the moles of both water (molar mass 18 g/mol) and methanol (molar mass 32 g/mol):

Hence, mole fraction is:

Next, mass percent is:

And the molality, considering the mass of water in kg (0.185 kg):

Regards.
Answer: e) all of these
Explanation:
Element is a pure substance which is composed of atoms of similar elements.It can not be decomposed into simpler constituents using chemical reactions.Example: Copper
Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.It can be decomposed into simpler constituents using chemical reactions. Example: water
, carbon dioxide 
Mixtures are not pure substances as they consist of elements and compounds combined physically and not in any fixed ratio. Example: Air
Thus all given substances are pure substances.
Mole ratios<span> are important because mole ratios allow you change moles of a substance to moles of another substance.</span>