Data Table 1. Mass of flask +iodine - Mass of empty flask Mass of iodine used 83
ID: 538225 • Letter: D
Question
Data Table 1. Mass of flask +iodine - Mass of empty flask Mass of iodine used 83.310 3.388g 2. 002 2.00c Mass of zinc used Observations after addition of methanol: The cotor immadia ations after addition of methanol: d e Zinc iodide is produced in the reaction. Where is it? At the bothom of lask Data Table 2. //0.75 8 109 (o45 1.11302 Mass of beaker+crystals - Mass of beaker Mass of crystals formed Data Table 3 Mass of flask + solid; 1t weighing Mass of flask +solid; 2hd weighing Mas of fask + solid, 5" weighing GF 72641 82,0410 necessary) unnucos Mass of excess reactant recovered -1.253 a What color are the crystals that formed in the beaker? uhiteExplanation / Answer
The resulting Zinc Iodide will remain in solution. Because the Zinc is used in excess, some powdered Zinc will remain at the bottom of the flask even after all the dark brown color of the Iodine has cleared. Zinc Iodide will form a pale yellow solution in Methanol.
The solution can be poured off the remaining Zinc and the Methanol subsequently evaporated to give pure Zinc Iodide as a solid. Hence crystal formed are Zinc Iodide which is obtained after evaporating the excess of methanol.
There are some mannual error during experiment because mole of zinc reacted must be equal to mole of I2. But Here mole of Zn and I2 are not in equimolar ratio. It may happen that you have decanted the excess methanol from solution instead of evaporating , which cause some loss of Zinc Iodide with solution.
Otherwise you can see that if I2 is limiting reagent then mass of ZnI2 must be more than total mass of I2. but in your case it is less than 2 which can't happen according to law of conservation of mass.
hence all calculation are correct but experimental observation may be wrong.
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