It had been a good year for the O\'Keefe farm with just the right amount of sun
ID: 567468 • Letter: I
Question
It had been a good year for the O'Keefe farm with just the right amount of sun and rain. In fact, the cucumbers had grown so well that Farmer Richard was afraid he wouldn't be able to sell them fast enough. Faced with the prospect of a warehouse full of rotten cukes, he contemplated the idea of preserving them and selling them as O'Keefe's Farm Fresh Pickles". He discussed the plan with his wife, Diane, who agreed it was a good idea and said she had a delicious pickling recipe that had been handed down to her from her mother. "I recall one of the ingredients was alum. I think it helps to keep the pickles firm and crisp", Diane said. "It just so happens that I know of a recipe for making alum from aluminum soda cans", Richard said. "We can use some of those soda pop cans that have been piling up, and that should save us some money." “How can you convert aluminum metal into an aluminum salt?" Diane asked. Richard explained the chemistry behind the process: One of the interesting properties of aluminum is that it is amphoteric, meaning it will dissolve in both strong, aqueous acids and strong, aqueous bases. Once we process the alum, we can make our pickles I. Describe why you should NOT expect a 100% yield of alum crystals from either soda cans or aluminum foil? (2 Pts) 2. How does the solubility of the alum in water change with temperature? Reference page(s) from Lab notcbook (2 Pts) 3. Why should you not rinse your alum crystals with pure distilled water? (2 Pts) 4. Showing all work and proper laboratory equipment, Describe how you would prepared 500.00 mof a 9.00 M H SO, solution from and 18.00 M (concentrated) grade sulfuric acid. (4 pts)Explanation / Answer
1. hence the yield is not 100% because the cans or the aluminium foils we have used is not purely aluminium metals, the cans or foil is covered with plastics and organic paint layers. so at the time of crystalizations only the Aluminium metal associated with that can or foil will make crystals leaving the palstics or paints as waste material.
2. solubility of the alum in water will increase with increase in temparature, but the increment is not sharp, at initial stages the solubility is not increasing at much extent, then after 500 C it increases rapidly.
3. distilled water is free from metal ions and contaminations, cryatallization happens at super saturated conditions of the solute, now if we will use distilled water the solution will not be saturated any more, extra water will break the crystall system.
4. we know, V1*S1=V2*S2 hence in this problem V2= 500ml, S2= 9(M), S1= 18(M) V1= ?
on calculation we got V1= 250ml, so we need 250ml of 18 (M) concentrate sulfuric acid and 250ml of water (500ml-250ml=250ml) to prepare 500 ml of 9(M) sulfuric acid.
to prepare this solution we will take 250ml of water in a beaker, then we have to add very slowly 18(M) sulfuric acid with constant shaking with the help of a glas rod, while adding concentrated sulfuric acid to water put the beaker in an ice bath under a chemical hood, beacuse this reaction is highly exothermic in nature.
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.