Expt 6:

Question 1

Describe the purpose of this lab?

Answer 1

Use a transfer hydrogenation of an alkene –> alkane

Question 2

What kinds of fats are alkenes and alkanes”

Alkene–>Alkane?

Answer 2

unsaturated–>saturated.

Question 3

What do hydrogenation reactions require?

Answer 3

a finely divided metal catalyst.

Question 4

What is palladium?

Answer 4

a finely divided metal catalyst.

Question 5

What kind of molecule is ammonium formate?

Answer 5

hydrogen donor

Question 6

What does a hydrogen donor do in the presence of metal catalyst?

Answer 6

it decomposes molecules. In the case of experiment 6: ammonium, carbon dioxide and hydrogen.

Question 7

What is the point of a permanganate test and what should the results be if our lab was conducted correctly?

Answer 7

• The test measures the presence or absence of double bonds, which tells us if we effectively turned an alkene into an alkane; or if the unsaturated fat became saturated.
• starting material should yield a color change which tells us that their is a presence of a double bond.
• The product should remain the same pink/purple color through the duration of the lab.

Question 8

Given:

• you have .250 g of oleic acid (molar mass: 282.46 G/mol)
• the ratio of ammonium formate: oleic acid is 4:1.
• molar mass of ammonium formate is 63.06.
• Calculate the amount of ammonium formate that should be formed.

Answer 8

.22 g

Question 9

How does one calculate limiting reagent?

Answer 9

Limiting reagent Is found by converting both starting materials into their mole amounts and then dividing each by their molar mass. Next, multiply each by their mol ratio. The smaller one is the limiting reagent.

Question 10

Calculate the theoretical yield given the following:

• .250 g of oleic acid (limiting reagent)
• 282.46 g of oleic acid - Molar mass
• molar mass of product: stearic acid: 284.48 g

Answer 10

.252 g stearic acid.

Question 11

given you know what the hydrogen donor decomposes into, what is the correct moleucle?

Answer 11

NH4+ HCO2-

Question 12

Which layer from the separatory funnel contains the stearic acid product in this experiment?

Answer 12

Organic layer (bottom layer)

Question 13

If you were provided 0.159 g of oleic acid for this hydrogenation experiment, and needed to calculate a 4 mole equivalent of ammonium formate (same calculation done on your pre-lab report), what mass of ammonium formate in g would you need?

MW of oleic acid: 282.48

MW of ammonium formate: 63.06

Answer 13

0.142