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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: Luke on October 19, 2015, 04:04:25 AM

Title: How do i find the theoretical mass?
Post by: Luke on October 19, 2015, 04:04:25 AM

I did a lab experiment where I liquefy aluminum in 2 M KOH.

After its liquefied I filtered it and had to wait about 48 hours until it crystalized and weighed it

side note: i screwed up the data when I accidentally threw it in the trash because my partner wrapped it up in paper towels and I assumed it was trash where I eventually dug it out ...Any who its the calculations that my professor is most concerned about

Mass of aluminum: 0.445

mas of filter paper: 0.478

mass of filter paper and dried alum crystals: 0.786

Calculations: 0.308

theoretical mass of alum possible: ?

percent yield: ?

percent yield = (actual yield/theoretical) yield x 100

whats my actual yield and how do I get theoretical yield?

Title: Re: How do i find the theoretical mass?
Post by: Borek on October 19, 2015, 04:22:55 AM

Quote from: Luke on October 19, 2015, 04:04:25 AM

whats my actual yield

You have already calculated it, didn't you?

Quote

how do I get theoretical yield?

Theoretical yield is the one given by the stoichiometry. You have not described the procedure, but I guess everything other than Al was in excess, which makes Al a limiting reagent.