Which of the following is a Lewis acid?
(For polyatomic species, consider the Lewis acid behaviour of the central atom).
a. ) NH3
b. ) F-
c. ) H2O
d. ) PF5
e. ) BF3
Don't know why the options didn't show.
they are
NH3
F-
H2O
PF5
BrF3
The others didn't show probably because you tried to copy and paste. That doesn't work. You must type what you want to post.
My recommendation:
Draw the Lewis electron dot structure for each of the molecules you list. Then look to see which of the central ions can accept electrons.
Thanks for the headsup.
Yeh I have drawn the Lewis structures. How do I know which ions can accept electrons? Does that mean it has a unpaired electron?
To determine which of the following is a Lewis acid, we need to understand what a Lewis acid is.
A Lewis acid is a substance that can accept a pair of electrons, usually in the form of a lone pair from another molecule or ion. In other words, it acts as an electron pair acceptor.
To determine if a species is a Lewis acid, we can look for a central atom that has an empty orbital available to accept an electron pair.
Let's analyze each of the options given:
a. NH3: Ammonia (NH3) has a central nitrogen atom with a lone pair of electrons. It can donate its lone pair and act as a Lewis base, but it cannot accept an electron pair. Therefore, NH3 is not a Lewis acid.
b. F-: Fluoride ion (F-) has a filled valence shell of electrons and cannot accept an electron pair. It is a Lewis base, not a Lewis acid.
c. H2O: Water (H2O) has a central oxygen atom with two lone pairs of electrons. It can donate these lone pairs and act as a Lewis base, but it cannot accept an electron pair. Therefore, H2O is not a Lewis acid.
d. PF5: Phosphorus pentafluoride (PF5) has a central phosphorus atom with an empty d orbital available to accept an electron pair. It can act as a Lewis acid by accepting a lone pair from another molecule or ion. Therefore, PF5 is a Lewis acid.
e. BF3: Boron trifluoride (BF3) has a central boron atom with an empty p orbital available to accept an electron pair. It can act as a Lewis acid by accepting a lone pair from another molecule or ion. Therefore, BF3 is a Lewis acid.
Based on the analysis above, the Lewis acids among the given options are d. PF5 and e. BF3.