Question

short note on DDT in chemistry

Answer 1

dichloro diphenyl trichloromethane is an colorless , tasteless , odourless chemical compound . uses: insecticide

Answer 2

DDTNamesPreferred IUPAC name1,1'-(2,2,2-Trichloroethane-1,1-diyl)bis(4-chlorobenzene)IdentifiersCAS Number50-29-3 3D model (JSmol)Interactive imageChEBICHEBI:16130 ChEMBLChEMBL416898 ChemSpider2928 ECHA InfoCard100.000.023KEGGD07367 PubChem CID3036UNIICIW5S16655 InChI[show]SMILES[show]PropertiesChemical formulaC14H9Cl5Molar mass354.48 g·mol−1Density0.99 g/cm3Melting point108.5 °C (227.3 °F; 381.6 K)Boiling point260 °C (500 °F; 533 K) (decomposes)Solubility in water25 μg/L (25 °C)[1]HazardsMain hazardsToxic, dangerous to the environment, likely carcinogenicGHS pictogramsGHS signal wordDangerGHS hazard statementsH301, H351, H372, H410GHS precautionary statementsP201, P202, P260, P264, P270, P273, P281, P301+310, P308+313, P314, P321, P330, P391, P405, P501NFPA 704220Flash point72–77 °C; 162–171 °F; 345–350 K [3]Lethal dose or concentration (LD, LC):LD50 (median dose)113–800 mg/kg (rat, oral)[1]
250 mg/kg (rabbit, oral)
135 mg/kg (mouse, oral)
150 mg/kg (guinea pig, oral)[2]US health exposure limits (NIOSH):[4]PEL(Permissible)TWA 1 mg/m3 [skin]REL(Recommended)Ca TWA 0.5 mg/m3IDLH (Immediate danger)500 mg/m3Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is  ?)Infobox references

Dichlorodiphenyltrichloroethane, commonly known as DDT, is a colorless, tasteless, and almost odorless crystallinechemical compound, an organochlorine, originally developed as an insecticide, and ultimately becoming infamous for its environmental impacts. First synthesized in 1874, DDT's insecticidal action was discovered by the Swiss chemist Paul Hermann Müller in 1939. DDT was used in the second half of World War II to control malaria and typhus among civilians and troops. Müller was awarded the Nobel Prize in Physiology or Medicine "for his discovery of the high efficiency of DDT as a contact poison against several arthropods" in 1948.[5]

By October 1945, DDT was available for public sale in the United States. Although it was promoted by government and industry for use as an agricultural and household pesticide, there were also concerns about its use from the beginning.[6]Opposition to DDT was focused by the 1962 publication of Rachel Carson's book Silent Spring. It cataloged environmental impacts that coincided with widespread use of DDT in agriculture in the United States, and it questioned the logic of broadcasting potentially dangerous chemicals into the environment with little prior investigation of their environmental and health effects. The book claimed that DDT and other pesticides had been shown to cause cancer and that their agricultural use was a threat to wildlife, particularly birds. Its publication was a seminal event for the environmental movement and resulted in a large public outcry that eventually led, in 1972, to a ban on DDT's agricultural use in the United States.[7] A worldwide ban on agricultural use was formalized under the Stockholm Convention on Persistent Organic Pollutants, but its limited and still-controversial use in disease vector control continues,[8][9] because of its effectiveness in reducing malarial infections, balanced by environmental and other health concerns.

Along with the passage of the Endangered Species Act, the United States ban on DDT is a major factor in the comeback of the bald eagle (the national bird of the United States) and the peregrine falcon from near-extinction in the contiguous United States.[10][11]