Choose one on left and choose on on right to create a high molar mass compound. do the same for lower molar mass compound

Assuming that you cannot repeat the same element (like trichlorine trichlorine), the best answer for high mass would be trioxygen trichloride and the best choice for low molar mass would be oxygen monochloride (if monochloride is an option, you have monoxide written twice).

Hi + naoh -> h2o + nal