[NewbieScience66]

HI,
I looking for someone that can check my work to make sure I am heading the right direction... thanks

So this what I have now.... am I on the right track.... I am stuck now on what 1:1 ratio is asking about...which on is the reactant and the product...

a. 2-propanol (60.10g/mol) has a density of 0.785 g/ml.  Calculate the mg in 825 uLs of 2-propanol.; Calculate the moles of 2-propanol in 825 uLs.   

825 uL = .825 ml
0.785 g/ml=mass/(.825 ml)

(.825 ml)0.785 g/ml= .647625 g

.647625 g ×1000=647.625 mg of 2"-propanol"

b. A dehydration reaction calls for 125 mmoles of cyclohexanol.  The density of cyclohexanol is 0.948.  Calculate the volume in mLs needed for the experiment.

0.125 moles ((100.158 g cyclohexanol)/(1 mol))  ((1 ml)/(0.948g cyclohexanol))=13.206 ml

c. The same reaction produces 0.495 grams of cyclohexene.  Calculate the moles of cyclohexene produced. 

0.495 g ((1 mol)/(82.143g cyclohexene))=0.00602 moles of cyclohexene


 Assume a 1:1 molar ratio of reactant to product in this reaction.  What is the theoretical yield of the product, cyclohexene, in moles?  What is the percent yield of cyclohexene?

[Dan]

a. 2-propanol (60.10g/mol) has a density of 0.785 g/ml.  Calculate the mg in 825 uLs of 2-propanol.; Calculate the moles of 2-propanol in 825 uLs.  

825 uL = .825 ml
0.785 g/ml=mass/(.825 ml)

(.825 ml)0.785 g/ml= .647625 g

.647625 g ×1000=647.625 mg of 2"-propanol"

The number is OK, but the number of significant figures is inappropriate.

You were also asked to find the moles, which you've not done.

b. A dehydration reaction calls for 125 mmoles of cyclohexanol.  The density of cyclohexanol is 0.948.  Calculate the volume in mLs needed for the experiment.

0.125 moles ((100.158 g cyclohexanol)/(1 mol))  ((1 ml)/(0.948g cyclohexanol))=13.206 ml

Again, check significant figures, otherwise OK.

c. The same reaction produces 0.495 grams of cyclohexene.  Calculate the moles of cyclohexene produced.  

0.495 g ((1 mol)/(82.143g cyclohexene))=0.00602 moles of cyclohexene

Fine.

Assume a 1:1 molar ratio of reactant to product in this reaction.  What is the theoretical yield of the product, cyclohexene, in moles?  What is the percent yield of cyclohexene?

It means that 1 mol of cyclohexanol can produce 1 mol of cyclohexene.

Theoretical yield is the maximum amount of product (cyclohexene) that can theoretically be produced from the starting material (cyclohexanol).

The actual percent yield an expression of the actual amount of material you get experimentally as a percentage of the theoretical yield. E.g. if the theoretical yield is 4 g, then I do the experiment and get 3 g, my yield is 75% (because 3 is 75% of 4, or (3/4)*100 = 75).