Презентация по английскому "Хлор"

 

 

 

 

Physical and chemical properties of chlorine

 

 

 

 

   Chlorine is a chemical element with symbol Cl and atomic number 17. Chlorine is in the halogen group and is the second lightest halogen after fluorine. It has the highest electron affinity and the third highest electronegativity of all the elements

 

 

 

 

  At standard conditions chlorine is a greenish-yellow gas with a sharp irritating odour, toxic. It in 2,5 times is heavier some air. In 1 volume of water at the 20°C, dissolves about 2 volumes of chlorine. This solution is called chloric water

 

 

 

 

   At atmospheric pressure chlorine at -34°C passes to a liquid state, and at -101°C hardens. At room temperature it passes in liquid condition only at pressure of 6 atm. Chlorine well dissolve in many organic solvents, especially in tetrachloride of carbon, but doesn't react with him

 

 

 

 

   At outer electronic level atom of chlorine has 7 electrons (s2p5) because it easily attaches an electron, forming Сl^-. Owing to existence of the blank d-level in atom of chlorine there can be 1, 3, 5 and 7 not coupled electrons therefore in oxygen compounds can have extent of oxidation +1, +3, +5 and +7

 

 

 

 

   In lack of moisture chlorine is quite inert, but in presence moisture traces its activity sharply increases. It well react with metals:

2 Fe+ 3 Cl² = 2 FeCl³

 

Cu + Cl² = CuCl²

 

 

 

 

   and many non-metals:

   H_² + Cl_² = 2HCl

   2S + Cl_² = S_²Cl_²

   Si + 2Cl_² = SiCl_⁴

   2P + 5Cl_² = 2PCl_⁵

 

   With oxygen, carbon and nitrogen chlorine doesn't react

 

 

 

 

   At chlorine dissolution in water two acids are formed: hydrochloric and hypochlorous:

   Cl_² + H_²O = HCl + HClO

   

At chlorine interaction with cold solutions  of alkalis the corresponding salts are  formed:

   Cl_² + 2 NaOH = NaCl + NaClO + H_²O

 

 

 

 

   By heating chlorine easily react with many organic substances. In limiting and aromatic hydrocarbons it replaces hydrogen, forming organochlorine connection and hydrogen chloride, and to nonlimiting joins in a place of double or threefold communication.

CH_⁴ + CI_² = CH_³CI + HCI

CH_³CI + CI_²= CH_²CI_² + HCI

CH_²CI_²+ CI_² = CH_³CI + HCI

CHCI_³ + CI_²= CCI_⁴ + HCI

 

 

 

 

   Chlorine is a strong oxidizer therefore easily react with difficult substances which structure includes the elements, can be oxidized to higher valency condition:

2 FeCl_² + Cl_² = 2 FeCl_³

H_²SO_³ + Cl_² + H_²O = H_²SO_⁴ + 2 HCl

 

 

 

 

Questions for check

 

  1. Physical properties of chlorine.

  2. Why oxygen compounds can have

      extent of oxidation +1, +3, +5 and +7?

  3. With what reacts chlorine?

  4. What are formed at chlorine dissolution in water?

  5. Does chlorine a strong oxidizer or reducer?