Practical chem

• Test for water vapour:-

  1. turns white anhydrous copper sulphate blue
  2. turns blue cobalt chloride paper pink
• Tests for hydrogen:-

  1. burning splinter is extinguished by hydrogen
  2. burns with pale blue flame producing pop sound
• Tests for oxygen:-

  1. rekindles a glowing splinter
• Test for co2:-

  1. Burning splinter is extinguished in co2
  2. co2 turns lime water milky, on excess passage it becomes clear
• tests for sulphur dioxide:-

  1. burning splinter is extinguished in so2
  2. turns lime water milky, on excess passage it becomes clear.
  3. turns KMno4 pink to colourless
  4. turns k2cr2o7 orange to clear green

  odour : suffocating
• tests for chlorine:-

  1. turns blue litmus red and then bleaches it
  2. turns moist starch iodide blue to black

  colour: greenish yellow

  odour: pungent
• test of hcl:-

  forms curdy white ppt on passage through agno3

  odour: pungent
• test for h2s:-

  1. turns KMnO4 pink to colourless
  2. turns k2cr2o7 orange to green
  3. turns lead acetate paper silvery black

  odour: rotten egg
• tests for no2:-

  1. turns potassium iodide paper brown

  odour: irritating

  colour: reddish brown
• test for nh3:-

  1. dense white fumes of nh4cl
  2. turns nessler's re agent from colourless to pale brown

  odour: pungent
• colour of compounds:-

  1. Cuo - black
  2. ZnO - yellow hot, white cold
  3. Pbo- buff yellow

  flame

  1. sodium - golden yellow
  2. potassium - lilac
  3. calcium - brick red
  4. copper green