Part a what is the predominant intermolecular force in the liquid state of each of these compounds: ammonia (nh3), carbon tetrabromide (cbr4), and dichloromethane (ch2cl2) ?

The predominant inter-molecular forces in the compounds are as follows:

ammonia - hydrogen bond.

carbon tetrabromide - dispersion forces.

dichloro methane - dipole - dipole forces.

Dipole - dipole forces usually predominates in polar compounds and hydrogen bond predominates in compounds that have OH, NH OR HF.