Because gravity treats all mass equally. It doesn't treat heavier objects with greater force. All objects experience the gravitational pull equally. Making the two different weights reach the ground together simultaneously despite their weight differences.
The answer is D because there are different molecules, and you need two or more different things in a compound.
<u>Answer:</u> The molar mass of the given unknown compound is 50.5 g/mol.
<u>Explanation:</u>
To calculate the volume of water, we use the equation given by ideal gas, which is:

or,

where,
P = pressure of sample = 1.00 atm
V = volume of sample = 2010 mL = 2.010 L (Conversion factor: 1 L = 1000 mL)
m = Given mass of unknown compound = 2.73 g
M = Molar mass of unknown compound = ? g/mol
R = Gas constant = 
T = temperature of sample = ![180^oC=[180+273]K=453K](https://tex.z-dn.net/?f=180%5EoC%3D%5B180%2B273%5DK%3D453K)
Putting values in above equation, we get:

Rounding off to 3 significant figures, we get the molar mass to be 50.5 g/mol.
Hence, the molar mass of the given unknown compound is 50.5 g/mol.