Which of the following molecules acts as a Lewis acid?(CH3)2O(CH3)3P(CH3)3 N(CH3)3 B

A Lewis acid is a chemical species that contains an empty orbital which is capable of accepting an electron pair from a Lewis base to form a Lewis adduct.

Looking at the given molecules:

1. (CH3)2O: This is dimethyl ether. It has no empty orbitals and cannot accept an electron pair, so it is not a Lewis acid.

2. (CH3)3P: This is trimethylphosphine. Phosphorus has an empty d orbital and can accept an electron pair, but in this case, all of its orbitals are filled with electrons from the three methyl groups and the lone pair, so it is not a Lewis acid.

3. (CH3)3N: This is trimethylamine. Nitrogen does not have an empty orbital and cannot accept an electron pair, so it is not a Lewis acid.

4. (CH3)3B: This is trimethylborane. Boron has an empty p orbital and can accept an electron pair, making it a Lewis acid.

So, the molecule that acts as a Lewis acid is (CH3)3B.