reactions of chlorine

• what are the two reactions of chlorine?

  purification of water - chlorine and water

  production of bleach - chlorine and cold dilute NaoH
• what is purification of water?

  small amounts of chlorine added to kill bacteria
• what is the equation for water purification?


  Cl2 (aq) + H2O (l) --> HCl (aq) + HClO (aq) (- mild bleaching agent)
• what is the benefit of using chlorine?

  it can be used to kill bacteria in water treatment
• what is the risk of using chlorine?

  chlorine gas is toxic and could form chlorinated hydrocarbon (free radical substitution)
• if chlorine is bubbled through water and then universal indicator:

  immediately - red colour

  after some time - colourless

  why? its bleached out
• bleach has the formula of NaClO which is called sodium chlorate (I)
• equation for chlorine and cold aqueous NaOH

  Cl2 (g) + 2NaOH (aq) -> NaClO (aq) + NaCl (aq) + H2O (l)
• equation for chlorine and hot concentrated NaOH

  3Cl2 (g) + 6NaOH (aq) -> NaClO (aq) + 5NaCl (aq) + H2O
• chlorine to bleach: cold dilute sodium hydroxide