1) Which one of the following molecules is the most polarizable?
a) H3C – I b) H3C – CH3
c) H3C – F
d) H3C – H e) H3C – OH
I chose H3C-I as the answer because the mm was the greatest. I added the mm of H, C, and I and got 141.934. Did I do this correctly?
I would have chosen c since the electronegativity of F is higher than any of the others.
I think it's A because you are looking at increasing molar mass in the halogens
To determine the most polarizable molecule among the options given, you need to consider the size and the electronegativity difference between the atoms in the molecule. A more polarizable molecule is one that can easily distort its electron cloud.
Electronegativity measures an atom's ability to attract electrons towards itself. Generally, the higher the electronegativity difference between two atoms, the more polar the bond between them.
In this case, you need to consider the difference in electronegativity between carbon (C) and the other atoms (H, F, and I) in the molecule. The electronegativity values are as follows:
Carbon (C): 2.55
Hydrogen (H): 2.20
Fluorine (F): 3.98
Iodine (I): 2.66
Looking at the options provided:
a) H3C – I: Carbon and iodine have an electronegativity difference of 2.55 - 2.66 = -0.11
b) H3C – CH3: Carbon and carbon have an electronegativity difference of 2.55 - 2.55 = 0
c) H3C – F: Carbon and fluorine have an electronegativity difference of 2.55 - 3.98 = -1.43
d) H3C – H: Carbon and hydrogen have an electronegativity difference of 2.55 - 2.20 = 0.35
e) H3C – OH: Carbon and oxygen have an electronegativity difference of 2.55 - 3.44 = -0.89
From the options given, H3C – F has the highest electronegativity difference (-1.43), and thus, it is the most polarizable molecule.
In summary, the correct answer is option c) H3C – F. Your approach of considering electronegativities to determine polarity is correct. However, it is important to note that the term "most polarizable" refers to the molecule's ability to distort its electron cloud, not the sum of the atomic masses (mm) of the atoms involved.