Conventional electrolytic cells are usually cumbersome and simulated with fragile open ended glass wares such as beakers, tubes, troughs or tanks which are prone to interference and contamination. Electrolytic cell was designed by allotting dimensions for its length: 12.0 cm, breadth: 6.0 cm and height: 8.0 cm to the cell; its casing for 9.0 V power source was allotted 2.5 cm length, 2.5 cm breadth and 2 .5 cm height; bores for dispensing and draining out spent (used) electrolyte and those for fixing electrodes were allotted 1.2 cm diameter; it was also designed to have an innovated switch and electrodes storage facility (compartment) of 7.0 cm length, 2.5 cm breadth and 2.5 cm height with ammeter separately fixed at the left edge of the cell’s electrolytes compartment. Perspex was used to construct a compact, durable and portable unit of electrolytic cell. Capacity of the cell was determined to be 500 cm 3 . Compactability tests show that the designed and constructed electrolytic cell is a compact unit. Conventional and the compact (constructed) electrolytic cells were separately used to perform electrogravimetry (electrolysis) 25.0 cm 3 aliquot at 0.2 A for 10, 20, 30, 40, 50 and 60 mins. Relationship between mass (g) of electroplated Cu and time (10 to 60 mins) taken to electrolyze Cu in 25 cm 3 aliquot was determined where conventional electrolytic cell electroplated 0.02 g to 0.22 g of Cu, compact electrolytic cell electroplated 0.03 g to 0.23 g of Cu and theoretically calculated mass of electroplated Cu in 25 cm 3 aliquot was 0.04 g to 0.24 g respectively. Statistical comparison of the two set of systems at 95.0% percent confidence level indicated a significant difference in their performances. However at 99.0% - 99.9% confidence level the comparison showed that there is no significant difference in their performances. The results of this study buttress that Perspex is a good material for constructing compact, durable and portable electrolytic cells. It also showed that the constructed electrolytic cell is highly a sensitive tool as revealed by its ability to electroplate higher mass of electroplated copper than the conventional cell; that mass of electroplated copper and time of electrolysis have a positive correlation and statistical analysis revealed that the two sets of methods do not agree significantly with each other at 95.00% confidence level but they agree significantly with each other beyond this.
The paradigm shift in the trend of chemistry from classical methods of analysis to instrumental methods has to do with system development and in the field of electrochemical analysis such system development will be incomplete without innovations in the area of voltaic and electrolytic cells.
According to [
Measurement according to [
Electrolysis and/or voltaic processes are the basis or the fundamental principles of three basic electro-analytical methods: electrogravimetry, potentiostatic coulometry and amperostatic coulometry or coulometric titration. The understanding of voltaic or galvanic cell and electrolytic cell is the knowledge of such electro-analytical techniques [
In this study, a compact, durable and portable electrolytic cell was designed, constructed and used for electrogravimetric determination of copper to study the relationship between mass of electroplated copper and time of electrolysis compared with the use of conventional electrolytic cell which is usually simulated with opened fragile glass wares (in which electrolytes are prone to interference and contamination) whose assemblage is so cumbersome such that one person cannot lift it up. Statistical test of significant difference between the two methods was done. Local materials were used to design and construct the cell in Nigeria.
According to [
Electrolytic cells were first invented in 1875 by Doctor Charles Michel [
The amount of a substance consumed or produced at one of the electrodes in an electrolytic cell is governed Faraday’s law of electrolysis which states that such amount of a substance is directly proportional to the amount of electricity that passes through the cell [
As at the time of this study and write up, literature show that electrolytic cells are being assembled or constructed using beakers, tubes, tanks and troughs as vessels for electrolytes [
The following apparatus and materials were used; a panel of Perspex, meter rule, hacksaw, smoothing file, G-clamp, silicone adhesives, weighing balance, stop watch, rubber corks, crocodile clips, spatula, assorted glass wares, desiccators, wash bottle, sandpaper and carbon rods. The following instruments were used; ammeters, a drilling machine and oven.
The following reagents were used; copper (2) tetraoxosulphate (vi) pentahydrate (CuSO4∙7H2O), concentrated sulphuric acid (H2SO4), concentrated nitric acid (HNO3) and ethanol (CH3CH2OH).
Methods reported by several authors [
Meter rule was used to measure and mark the Perspex panel into the allotted dimensions specified in the design. The Perspex panel was then clamped and sawn into the required sizes using saw. The top and one of the side pieces of sawn panel were placed on a wooden platform, openings for dispensing, fixing electrodes and draining out spent or used electrolytes were drilled to 1.2 cm diameter.
Surfaces of sawn pieces of the Perspex panel were degreased, cleaned and dried. The base was placed on a work bench after which silicone adhesive was applied to its sides and edges. This was followed by attaching parts at angle 90˚ starting with sides, edges, top cover, power source casing and finally electrodes storage compartment. Flexible wires, crocodile clips and electrodes were fixed. The ammeter was attached at the left edge of the cell’s electrolytes compartment. Capacity of the cell was determined to be 500 cm3.
Relationship between mass of deposited copper and time of electrolysis was established or studied by plotting a graph of mass of electroplated copper against time of electrolysis.
The procedures for electrogravimetry reported by [
Plate 1 and Plate 2 are experimental set up constructed (compact) and conventional electrolytic cells for electrogravimetric (electrolysis) analysis.
Figures 2(s1)-(s6) shows different views of attempted designed and constructed compact, durable and portable unit of electrolytic cell indicating a smaller volume rigid and non-fragile covered or lidded plastic (Perspex materials) sample (electrolyte) cell, organized electrical wires, fixed ammeter, fixable power source (battery) and electrodes.
Compactability of the designed and constructed electrolytic cell was checked by tilting them, inclining them at different angles and transporting it from one place to another particularly, from Gwagwalada and Nasarawa to Makurdi as at 15th September, 2016 to date. These activities have not impacted any defect or
Plate 1. Experimental set up of compact electrolytic cell.
Plate 2. Experimental set up for simulated conventional electrolytic cell.
Conventional electrolytic cell | Designed and constructed electrolytic cell |
---|---|
It is cumbersome. | It is compact and portable. |
Its electrolytes compartment is made of fragile beaker which is opened hence prone to interference and contamination. | Its electrolytes compartment is made of durable plastic (Perspex) lidded material. |
Its electrodes are usually somehow suspended in the electrolyte resulting to uneven or non-uniform deposition of metal ions on its cathode. | Electrodes are fixed into electrolytes through bores designed for electrodes hence metal ions are evenly or uniformly deposited on the cathode. |
It has no switch. It operates only once both electrodes are immersed into the electrolyte. | It has innovated switch for smooth and better operations and results. |
negative effects on the cells if not for the removal of electrodes from the cells electrolytes compartments whenever they were turned upside down which is obvious. The constructed electrolytic cell is compact, durable and portable.
Average experimental mass of electroplated copper electrolyzed by the use of the conventional and compact electrolytic cells at various time of electrolysis is being compared with theoretical mass of electroplated copper in
Figures 4-6 show a comparative curve of experimental mass of electroplated copper electrolyzed by conventional and compact electrolytic cells relative to the
Average experimental mass of electroplated copper (g) | |||
---|---|---|---|
Time of electrolysis (mins) | Conventional E.C. | Constructed E.C. | Theoretical values |
10 | 0.02 ± 0.07 | 0.03 ± 0.07 | 0.04 ± 0.00 |
20 | 0.06 ± 0.07 | 0.07 ± 0.07 | 0.08 ± 0.00 |
30 | 0.10 ± 0.07 | 0.11 ± 0.07 | 0.12 ± 0.00 |
40 | 0.14 ± 0.07 | 0.15 ± 0.07 | 0.16 ± 0.00 |
50 | 0.18 ± 0.07 | 0.19 ± 0.07 | 0.20 ± 0.00 |
60 | 0.22 ± 0.07 | 0.23 ± 0.07 | 0.24 ± 0.00 |
Total mass of Cu (g) | 0.72 ± 0.07 | 0.78 ± 0.07 | 0.84 ± 0.00 |
Note: E.C. = Electrolytic cell.
theoretical mass of electroplated copper (g) versus time of electrolysis (mins), vertical and horizontal bar charts showing experimental mass of electroplated copper (g) against time of electrolysis (min) and time of electrolysis (min) against experimental mass of electroplated copper (g) for conventional, compact electrolytic cells and theoretical value respectively where length of each bar is proportional to the average experimental mass of electroplated copper it represents.
Data analysis and statistical tests conducted on data obtained from conventional and constructed electrolytic cells in line with [
Efficiency or percentage performance of the conventional electrolytic cell was determined according to method reported by [
Plate 1 is an experimental set up of the constructed compact, durable, portable and lidded unit of electrolytic cell providing interference-free electrolytic environment while Plate 2 is an experimental set up of conventional electrolytic cell showing how cumbersome and fragile it is with its vessel containing electrolyte opened hence prone to interference and contamination. The constructed electrolytic cell in Plate 1 is compact, portable and durable unit with lidded electrolyte (s) cell, vessel or compartment. It also has an innovation switch and the electrodes are fixed or immersed into electrolyte (s) through a bore designed to hold them in position. In contrast, the simulated conventional electrolytic cell in Plate 2 is so cumbersome in its arrangement. It is not durable because its vessel is a fragile beaker. It is open ended hence prone to interference and contamination. It has no switch―it operates only when the two electrodes are immersed in the electrolyte (s).
In
Relationship between mass of electroplated copper and time taken to electrolyze it determined using conventional electrolytic cell in line with [
It is observed that experimental mass of electroplated copper (g) which is directly proportional to time of electrolysis increased from 10 mins after which 0.02 g copper was electroplated followed by 20 mins, 30 mins, 40 mins, 50 mins and the longest time, 60 mins after which 0.22 g copper was electroplated in the conventional electrolytic cell.
However, relationship between mass of electroplated copper and time taken to electrolyze it studied in accordance to [
It is also observed that experimental mass of electroplated copper (g) which is directly proportional to time of electrolysis increased from 10 mins after which 0.03 g copper was electroplated followed by 20 mins, 30 mins, 40 mins, 50 mins and the longest time, 60 mins after which 0.23 g copper was electroplated in the constructed electrolytic cell. The values of standard deviation shown in
Data analysis and statistical tests conducted on data obtained from conventional and constructed electrolytic cells in line with techniques reported by [
Compact, durable and portable unit of electrolytic cell was designed and constructed using Perspex, a glass like plastic material. Electrolysis was carried out for 10 mins, 20 mins, 30 mins, 40 mins, 50 mins, and 60 mins at 0.2 A using the conventional and constructed electrolytic cells and mass of electroplated copper at each time was deduced. Total experimental mass of electroplated copper electrolyzed using conventional and constructed electrolytic cells is 0.72 g and 0.78 g respectively while theoretical mass of electroplated copper is 0.84 g. Statistical analysis on data obtained from the use of the conventional and constructed electrolytic cells showed that the two methods do not significantly agree with each other hence are not the same at 95.5%, 98.% and 99.0% confidence levels; however, they significantly agree with each other at 99.9% confidence level. Percentage performances of these cells are 85.5% performance for conventional and 92.86% performance for constructed electrolytic cells. Percentage error of conventional and constructed electrolytic cell is 14.29% and 7.15% respectively.
The results of this study buttress that Perspex is a good material for constructing compact, durable and portable electrolytic cells. Compact electrolytic cell provided better results than the conventional cell; that mass of electroplated copper and time of electrolysis have a positive correlation and statistical analysis of data obtained from the conventional and constructed electrolytic cell revealed that the two sets of methods do not agree significantly with each other at 95.00% confidence level but they agree significantly with each other beyond this confidence level to 99.9% confidence level.
Musa, D.E., Sha’Ato, R., Eneji, I.S. and Itodo, A.U. (2018) Electrogravimetric Determination of Copper Using a Constructed Compact Electrolytic Cell Open Access Library Journal, 5: e4446. https://doi.org/10.4236/oalib.1104446