Unit 4- Chemical Synthesis

Question 1

Calculate the cell volatage produced by the hydrogen fule cell under acidic conditions

Answer 1

1.23V

Question 2

Define what a reaction pathway is

Answer 2

A series of reactions that leads to the formation of the desired product.

Question 3

Give the names of the three different categories of biofuels

Answer 3

First, second and third generation biofuels

Question 4

How many principles of Green Chemistry are there?

Answer 4

12

Question 5

Hydration of ethene is produced through the __________ ___________ of products from crude oil

Answer 5

Catalytic cracking

Question 6

If tempertaure is increased during the Haber process, will the reactant or product be favoured?

Answer 6

Reactant

Question 7

In the Haber process, in which direction does the the equilibrium shift if the pressure is increased?

Answer 7

Right

Question 8

Is the haber process endothermic or exothermic?

Answer 8

Exothermic

Question 9

List the 2 ways ethanol can be synthesised

Answer 9

Fermentation and hydration of ethene

Question 10

List the requirements for fermentation.

Answer 10

Glucose from suitable grain, or fruit. Yeast. Constant temp (37 degrees) absence of air

Question 11

Name an enzyme that can be used as a biological catalyst in the production of biodiesel.

Answer 11

lipase

Question 12

Name the two main processes used for synthesising ethanol

Answer 12

Fermentation, hydration of ethene

Question 13

Name the two methods that can be used to synthesise biodiesel

Answer 13

base-catalysed and lipase-catalysed methods

Question 14

The process of converting one ester to another ester is called _________________

Answer 14

Transesterification

Question 15

True or false. A fuel cell is type of
galvanic cell

Answer 15

TRUE

Question 16

True or False. Both hydrogen fuel cells in acidic or basic conditions convert H2 & O2 into water.

Answer 16

TRUE

Question 17

True or False? Glycerin is a by-product of the production of biodiesel via transesterification of vegetable oil.

Answer 17

TRUE

Question 18

What are Biofuels?

Answer 18

Fuels produced from plants, algae or animal waste

Question 19

What does the contact process produce?

Answer 19

Sulphuric acid

Question 20

What does the Haber process produce?

Answer 20

Ammonia

Question 21

What do the twelve principles of green chemistry aim to reduce?

Answer 21

Waste, energy use, environmental impacts, risks & hazards

Question 22

What is biodiesel made from?

Answer 22

Triglycerides (fatty acids) and a short chained alcohol (eg methanol)

Question 23

What is steam reforming?

Answer 23

Production of hydrogen from fossil fuels

Question 24

What is the formula for the Haber Process?

Answer 24

N2(g) + 3H2(g) <-> 2NH3(g)

Question 25

What is the formula to calculate experimental atom economy?

Answer 25

Mass of desired product/Mass of all products x 100

Question 26

What is the formula to calculate theoretical atom economy?

Answer 26

(Molar mass of desired product x moles of product/Molar mass of all reactants x moles of reactants) x 100

Question 27

What is the Haber compromise?

Answer 27

Finding a temperature and pressure that produces enough Ammonia in adequate time without excessive costs or risks. 200atm at 450 degrees C

Question 28

What the name for the synthetic process used to synthesise sulfuric acid

Answer 28

contact process

Question 29

What type of fat is vegetable oil?

Answer 29

triglyceride

Question 30

When designing an optimal synthetic pathway there is a most often a competition between 2 factors. What are they?

Answer 30

The yield of product and the rate of formation of product.

Question 31

When producing Biodiesel from a trigylceride, what are the two products?

Answer 31

An ester and Gylcerol

Question 32

Why is vanadium oxide used as a catalyst in the production of sulphuric acid?

Answer 32

Increases the rate of reaction

Question 33

Why is water not added directly to sulphur trioxide in the contact process?

Answer 33

This would lead to an uncontrolled reaction. So the sulphur trioxide is added to sulphuric acid first before adding the water.

Question 34

Write the equation for the half reaction that occurs at the anode in a hydrogen fuel cell under acidic condictions

Answer 34

2H2 -> 4H+ + 4e-

Question 35

Write the equation for the half reaction that occurs at the cathode in a hydrogen fuel cell under alkaline conditions

Answer 35

O2 + 2H2O + 4e -> 4OH-

Question 36

Write the formula for the fermentation of glucose

Answer 36

C6H12O6(aq) -> 2C2H5OH(aq) + 2CO2