Answer:
Explanation:
The two green substances are not the same. Most of their properties are different, except some are alike. Since not all of their properties are matching, they are not the same substance.
I am not sure if this is what you were looking for, but if it is then I am happy to help.
Answer:

Explanation:
Since we have $N_A$ number of molecules in 22.4 L, in 15 L we have:
$\frac{15}{22.4}\times 6.023 \times 10^{23}$ molecules.
Answer:
D
Explanation:
Divide the mass by the volume.
Aqueous compounds are a mixtures of two electrolytes – the compound and water.
Does this help a little?
Answer:
The structures are attached in file.
Hydrogen bonding and intermolecular forces is the reason for ranks allotted.
Explanation:
In determining Lewis structure, we calculate the overall number of valence electrons available for bonding. Making carbon (the least electronegative atom) the central atom in the structure, we allocate valence electrons until each atom has achieved stability.
In order of decreasing affinity to water molecules:

This is due to the fact that the
will accept protons more readily than the bicarbonate ion,
. Carbonic acid,
will not accept any more protons, hence it is the least attractive to water molecule, even though soluble.