BREATHALYSERS

• WHAT DO BREATHALYSERS CONTAIN?

  K2CrO7/H2SO4 crystals and a silver nitrate catalyst
• WHAT HAPPENS WHEN BREATH PASSERS OVER THE CRYSTALS?

  any ethanol is oxidised by crystals
• WHAT HAPPENS WHEN THE ETHANOL IS OXIDISED BY THE CRYSTALS?

  yellow Cr (VI) is reduced to green Cr (III)
• WHAT DOES MORE ETHANOL LEAD TO?

  greater colour change
• WHAT DO MODERN BREATHALYSERS USE?

  fuel cell and current