Mohammed Salam Unit 13: LA B
Redox for industry
Electro cell practical:
Apparatus:
• Voltmeter, high resistance
• 3 x Measuring cylinders (20cm3)
• Filter paper strips
• 3 x connecting leads
• Crocodile clips
• 4 x beakers (50 cm3)
• Goggles
• Saturated potassium nitrate solution
• Emery paper (3 small pieces)
• Strip of lead wire
• Strip of zinc wire
• Lead (II) nitrate solution 0.1 M
• Strip of copper wire
• Zinc sulphate solution 0.1 M
• Copper sulphate solution 0.1 M
Method:
I cleaned the each of metal wire with a separate piece of emery paper. I placed each metal wires in a
separate beaker. Each of the metal wires were held vertically against the side of the beaker so that it
was above 2 cm. I also clamped it into position where I had to attach it to the crocodile clip with a
lead. I poured 20cm3 of salt solution into each beaker and ensured that each of the metal wires are
dipped into a solution with its own ions. When adding the salt solution into each beaker I made sure
that the crocodile clips remained dry. Salt bridge was made when by soaking a strip of filter paper in
saturated potassium nitrate solution. Any remained solution from the strip was drained off by
hanging it on the fourth beaker. I connected the two metals copper and zinc electrodes to a high
voltmeter; this makes it into form of a salt bridge. When I successfully connected it with a voltmeter
the reading was negative so I reversed the connections so that it can give a positive reading. The
potential difference was recorded into a result table. Once it was recorded, I quickly removed the
salt bridge and disposed it and disconnected the voltmeter. I repeated the procedure with the other
two cells where I had to prepare the salt bridge, connect it with the two metal electrodes, record the
potential difference and finally removing the salt bridge and disconnect the voltmeter.
Results:
Half Cells Measured Voltage (V) Literature Value (V)
Zinc and Copper 1.065 V 1.10 V
Zinc and Magnesium -6.03 V 1.61 V
Magnesium and copper -1.445 V 2.71 V
1
, Mohammed Salam Unit 13: LA B
Potassium dichromate colour change:
(www.chemistryland.com, n.d.)
Potassium dichromate changes colour from orange to green due to aldehyde reaction.
Titration iron against permanganate:
Apparatus:
• Burette
• Clamp and stand
• Pipette filler
• Beakers (250cm3)
• Wash bottle
• Distil water
• White tile
• Pipette (25cm3)
• Goggles
• Conical flask (250cm3)
• Graduated Cylinders (100cm3)
• Filter funnel
• Dilute Sulphuric acid
• Potassium Manganese solution
• Iron (II) solution
• Potassium manganate (VII) solution
Risk assessment:
Hazards Risk Mitigation
Glassware Cuts – if the glassware is Wear gloves when handling
broken and if it is sharp the broken glass.
enough it may cut through the
skin and can cause bleeding. Clean the site immediately.
Dilute sulphuric acid Irritant Wear goggles and gloves.
2
Redox for industry
Electro cell practical:
Apparatus:
• Voltmeter, high resistance
• 3 x Measuring cylinders (20cm3)
• Filter paper strips
• 3 x connecting leads
• Crocodile clips
• 4 x beakers (50 cm3)
• Goggles
• Saturated potassium nitrate solution
• Emery paper (3 small pieces)
• Strip of lead wire
• Strip of zinc wire
• Lead (II) nitrate solution 0.1 M
• Strip of copper wire
• Zinc sulphate solution 0.1 M
• Copper sulphate solution 0.1 M
Method:
I cleaned the each of metal wire with a separate piece of emery paper. I placed each metal wires in a
separate beaker. Each of the metal wires were held vertically against the side of the beaker so that it
was above 2 cm. I also clamped it into position where I had to attach it to the crocodile clip with a
lead. I poured 20cm3 of salt solution into each beaker and ensured that each of the metal wires are
dipped into a solution with its own ions. When adding the salt solution into each beaker I made sure
that the crocodile clips remained dry. Salt bridge was made when by soaking a strip of filter paper in
saturated potassium nitrate solution. Any remained solution from the strip was drained off by
hanging it on the fourth beaker. I connected the two metals copper and zinc electrodes to a high
voltmeter; this makes it into form of a salt bridge. When I successfully connected it with a voltmeter
the reading was negative so I reversed the connections so that it can give a positive reading. The
potential difference was recorded into a result table. Once it was recorded, I quickly removed the
salt bridge and disposed it and disconnected the voltmeter. I repeated the procedure with the other
two cells where I had to prepare the salt bridge, connect it with the two metal electrodes, record the
potential difference and finally removing the salt bridge and disconnect the voltmeter.
Results:
Half Cells Measured Voltage (V) Literature Value (V)
Zinc and Copper 1.065 V 1.10 V
Zinc and Magnesium -6.03 V 1.61 V
Magnesium and copper -1.445 V 2.71 V
1
, Mohammed Salam Unit 13: LA B
Potassium dichromate colour change:
(www.chemistryland.com, n.d.)
Potassium dichromate changes colour from orange to green due to aldehyde reaction.
Titration iron against permanganate:
Apparatus:
• Burette
• Clamp and stand
• Pipette filler
• Beakers (250cm3)
• Wash bottle
• Distil water
• White tile
• Pipette (25cm3)
• Goggles
• Conical flask (250cm3)
• Graduated Cylinders (100cm3)
• Filter funnel
• Dilute Sulphuric acid
• Potassium Manganese solution
• Iron (II) solution
• Potassium manganate (VII) solution
Risk assessment:
Hazards Risk Mitigation
Glassware Cuts – if the glassware is Wear gloves when handling
broken and if it is sharp the broken glass.
enough it may cut through the
skin and can cause bleeding. Clean the site immediately.
Dilute sulphuric acid Irritant Wear goggles and gloves.
2
