Methane (CH4), phosphorus trichloride (PCl3), and hydrogen sulfide (H2S) melt at −182°C, −112°C, and −86°C, respectively. What does this suggest about the polar character and intermolecular attractions of the three compounds? As the melting points increase from −182°C (methane) to −86°C (hydrogen sulfide), the molecules become polar and the intermolecular attractions .