Industrial Chemistry > 4. The industrial production of sodium hydroxide requires the use of electrolysis > The Products of The Electrolysis of Sodium Chloride >
Identify data, plan and perform a first-hand investigation to identify the products of the electrolysis of sodium chloride
- Different products can be formed when conducting electrolysis of sodium chloride
- Electrolysis of dilute NaCl produces oxygen gas at the anode and hydrogen gas + hydroxide ions at the cathode
- Electrolysis of concentrated NaCl produces chlorine gas at the anode and hydrogen gas + hydroxide ionsat the cathode
- Glowing splint test can be done to identify the gas formed at the electrode
- the gas formed is hydrogen if a ‘popping’ sound is heard
- the gas formed is oxygen if the splint reignites
- Litmus paper or indicators, such as phenolphthalein, can be used to identify products in solution form
- Presence of chloride ions results to bleaching of litmus paper
- Presence of hydroxide ion makes the solution with phenolphthalein turn purple
- Safety measures should be done when handling sodium hydroxide by wearing safety goggles and gloves to prevent burns and eye irritation
- Experiments involving chlorine gas should be done inside a fumehood as Cl2 gas is deemed toxic and can cause respiratory problems