A mixture of two or more substances used for killing pests are called pesticides. pests include insects, plant pathogens, weeds, mollusks, etc, that destroy the plant crop and spread diseases. Aldrin and dieldrin are the names of some common pesticides.Herbicides are pesticides specially meant for killing weeds. Examples include sodium chlroride (NaClO3​), sodium arsenite (Na3​AsO3​) etc.