[phoenixrising]

Ok so I'm not sure I know how to find theoretical yield
I need help

[discodermolide]

You have 10mmol of benzaldehyde, therefore you would expect 10mmol of the benzyl alcohol if the yield is 100%, what is that in grams?

[phoenixrising]

You have 10mmol of benzaldehyde, therefore you would expect 10mmol of the benzyl alcohol if the yield is 100%, what is that in grams?

0.0106 g

[discodermolide]

1.08 grams.
You are not using the molecular weights in your calculations.
In fact I'm not even sure what you have done in your calculations.

[phoenixrising]

1.08 grams.
You are not using the molecular weights in your calculations.
In fact I'm not even sure what you have done in your calculations.

Wait how did you get that

[discodermolide]

1.06 grams benzaldehyde is 10mmol or 0.010mol if the yield is 100% (Theoretical yield) then you get 0.010 mol of benzyl alcohol.
Benzyl alcohol has a MWt. of 108, therefore 0.010 mol = 1.08grams.

[phoenixrising]

1.06 grams benzaldehyde is 10mmol or 0.010mol if the yield is 100% (Theoretical yield) then you get 0.010 mol of benzyl alcohol.
Benzyl alcohol has a MWt. of 108, therefore 0.010 mol = 1.08grams.

Ohh...So 1.08 g is the answer right?

[discodermolide]

Yes, but do you understand how I got it?

[phoenixrising]

Yes, but do you understand how I got it?

Yes.

So essentially: If theoretical yield is 100%, theoretical yield = MW of Product x Amount of Moles of Limiting Reagent

[discodermolide]

The theoretical yield is what you would expect if the reaction goes to 100%, that is A is transformed to B, 1 mol of A gives 1 mole of B.
Now if you have 10grams of A with a MWt. of 100, that is 0.1 mol of A. As we just said 100% yield means you get 100% B, in this case 0.1 mol B. If the MWt of B is 200 then the yield in grams is 20g because you will get 0.1mol of B.

[phoenixrising]

The theoretical yield is what you would expect if the reaction goes to 100%, that is A is transformed to B, 1 mol of A gives 1 mole of B.
Now if you have 10grams of A with a MWt. of 100, that is 0.1 mol of A. As we just said 100% yield means you get 100% B, in this case 0.1 mol B. If the MWt of B is 200 then the yield in grams is 20g because you will get 0.1mol of B.

Ohh! that makes more sense! Thanks!!

[phoenixrising]

I have 2 more questions

Back to Aldol + NaOH chemistry...I can't get this one...



I made OH- attack the alpha carbon on the right of the ketone molecule (the ketone on the left)  and that made a carbanion/nucleophilic C. H2O was produced

I then tried to make that nucleophilic C attack the carbonyls carbon on the right side of the molecule to kick out 2 electrons in that C=O bond to make C-O^-. Then after that, I didn't know what t do exactly.
I proceeded to protonate that oxygen with H2O and after doing that, I used the OH- that was produced to attack that one alpha hydrogen sticking out and eventually kick out OH- and produce H2o and a Ketone structure with CH3 attached to the left and a triangle shape attached to the right...

I didn't submit this structure because I thought it looked wrong and so I guessed again what the structure would look like and I submitted the one above

[discodermolide]

Well this is another aldol condensation. The product you are talking about is this one?


Draw out the steps to this product and complete the aldol condensation.

[phoenixrising]

Well this is another aldol condensation. The product you are talking about is this one?


Draw out the steps to this product and complete the aldol condensation.

Is this the answer?

[discodermolide]

Not quite, compare it with mine.