37 u00b0 c water bath the anodes and cathodes were made of lead and aluminium respectively the laboratory supplied msds sheet indicated for the electrolyte the following composition zinc sulfate 28 34 by weight magnesium sulfate 9 15 g l grams litre and manganese 1 5 2 5 g l after allowing the temperature inside the test cells to reach the desired value of 37 u00b0 c a constant current of 0 045 a representing an electrowinning current density of 450 amperes meter 2 was applied for either 4 or 20 hours to a non agitated electrolyte after completion of the experiment the electrode assembly was removed from the glass beaker rinsed with distilled water and the cathode deposit carefully scraped off and weighed with four digits precision using a digital mettler ae 100 analytical balance the test cells were rinsed between experiments with distilled water and acetone in order to remove traces of the organic additives replicates were also performed and the standard deviation was estimated the zinc electrodeposition current efficiency was calculated based on faraday 39 s law ce u2062 u2062 z u00b7 f u00b7 m d i u00b7 t u00b7 a zn u00b7 100 1 ce u2014 current efficiency for zn electrodeposition z u2014 no of electrons exchanged 2 f u2014 faraday 39 s number 96485 3 c mol u2212 1 m d u2014 amount of zinc deposit g i u2014 applied current 0 045 a t u2014 time s a zn u2014 atomic weight of zinc 65 39 the cetylpyridinium chloride cpc e g sigma aldrich u s had the following structure.