[yourdeath01]

1)

We did a lab where we nitrated Napthalene using 2 mL of mixed acid (sulfuric and nitric acid). Being asked to go ahead and calculate theoretical yield and % yield of the crude and % recovery of the purified product!!

My data

Initial mass of Napthalene: 1.002 g

Mass of crude: 0.986 g

Of the crude only 0.200 g was used for recrystallization

Purified product mass: 0.003 g

Again calculate theoretical yield, % yield of crude product, % recovery of purified product!

Here is the overall reaction if needed:

https://imgur.com/ImXlofY I found out that theoretical yield of crude is going to be 1.354 g and so % yield of crude is 72.82%

I didn't use reagents to find limiting reagent or non of that cos I alrdy knew it was 1:1 ratio so I just multiplied initial mass by both molecular weight to get 1.354 g as my theoretical yield.

Here is my work: https://imgur.com/L40swOs

2)

But what about % recovery of purified product?

Is it mass of product extracted/starting mass x 100

SO,

0.003 g / 0.200 g * 100% = 1.5%?!

OR

is it also 0.200 g = 0.003 g

0.986 g =?

We cross multiply 0.986 g x 0.003 g/0.200 g = 0.0148

0.0148 g / 1.354g x 100% = 1.09% recovery?

[chenbeier]

Calculation sounds ok för me.

Because only  0.2 g of crued product was used for purification only this number can be used.