Qa

• Ca(II) and sodium hydroxide forms white precipitate calcium hydroxide Which is insoluble in excess
• Cu(II) and NaOH forms blue precipitate copper (II) hydroxide which is insoluble in excess
• To find carbonate add acid and bubble through limewater to get white precipitate which is calcium carbonate and the gas is carbon dioxide
• To find chloride add nitric acid then silver nitrate white ppt formed ,silver chloride
• To find nitrate add sodium hydroxide and aluminium foil and warm

  gas given off is ammonia
• To find sulfate add nitric acid and barium nitrate white ppt formed barium sulfate
• Black powder is carbon and oxides
• Reddish brown is copper