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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: confused!! on September 25, 2010, 01:28:21 PM

Title: Simple yield question but im lost
Post by: confused!! on September 25, 2010, 01:28:21 PM

So my experiment is preparation of Sodium Peroxoborate
The question im stuck on is calculate the yield you obtained

so from Na2[B2(O2)2(OH)4].6H2O i calculated the weight to be in total 302 from the periodic table.

The weight of my end product was 4.54g's.

And from here i got really lost ???. My teacher and I went through it and we got the theortical yield to be 5.9g but doing it now on my own im lost.

for my percentage yield i got 75.79%.

I dont knowhow to find the (mloar) yield because of the moles of reactant and moles of product.

I think my moles of product is 1.483 but dont know wat my moles of product is.

The equation is Na2[B4O5(OH)4].8H2O + 2NaOH + 4H202 ---> 2Na2[B2(02)2(OH)4].6H20 + 3H20

ANY HELP AT ALL WOULD BE REALLY APPRECIATED

i dont have anyone else to ask

Tanks soo much ;D

Title: Re: Simple yield question but im lost
Post by: Borek on September 25, 2010, 03:48:40 PM

You have listed what you don't know, but you failed to list what you do know - there are some data that the calculation should be based on. I guess you have started with some substance? Of known mass perhaps?