equilibrium in practicals

Question 1

A common experiment is working out the equilibrium constant is …,,.

Answer 1

esterification reaction. Ethanol and

ethanoic acid are mixed together with a sulphuric acid catalyst

Question 2

Method
Part 1
steps

Answer 2

Preparing the equilibrium mixture
1 Use burettes to prepare a mixture in boiling tube of carboxylic acid, alcohol, and dilute sulfuric acid.
2 Swirl and bung tube. Leave the mixture to reach equilibrium for one week

Question 3

Method

Part 1 step 1

Answer 3

1 Use burettes to prepare a mixture in boiling tube of carboxylic acid, alcohol, and dilute sulfuric acid.

Question 4

method
part 1
step 2

Answer 4

2 Swirl and bung tube. Leave the mixture to reach equilibrium for one week

Question 5

Part 2

Titrating the equilibrium mixture

Answer 5

1 Rinse a 250 cm3 volumetric flask with distilled water.
Use a funnel to transfer the contents of the boiling tube into the flask. Rinse the boiling tube with water and add
the washings to the volumetric flask.
2 Use distilled water to make up the solution in the volumetric flask to exactly 250 cm3
. Stopper the flask, then invert and shake the contents thoroughly. 3 Use the pipette to transfer 25.0 cm3 of the diluted equilibrium mixture to a 250 cm3 conical flask.
4 Add 3 or 4 drops of phenolphthalein indicator to the conical flask.
5 Set up the burette with sodium hydroxide solution..
6 Add the sodium hydroxide solution from the burette until the mixture in the conical flask just turns pink. Record
this burette reading in your table.
7 Repeat the titration until you obtain a minimum of two concordant titres.

Question 6

step 1 part 2

Answer 6

1 Rinse a 250 cm3 volumetric flask with distilled water.
Use a funnel to transfer the contents of the boiling tube into the flask. Rinse the boiling tube with water and add
the washings to the volumetric flask.

Question 7

step 7 part 2

Answer 7

7 Repeat the titration until you obtain a minimum of two concordant titres.

Question 8

step 6 part 2

Answer 8

6 Add the sodium hydroxide solution from the burette until the mixture in the conical flask just turns pink. Record
this burette reading in your table.

Question 9

step 5 part 2

Answer 9

5 Set up the burette with sodium hydroxide solution..

Question 10

step 4 part 2

Answer 10

4 Add 3 or 4 drops of phenolphthalein indicator to the conical flask.

Question 11

step 2 part 2

Answer 11

2 Use distilled water to make up the solution in the volumetric flask to exactly 250 cm3
. Stopper the flask, then invert and shake the contents thoroughly
.

Question 12

step 3 part 2

Answer 12

3 Use the pipette to transfer 25.0 cm3 of the diluted equilibrium mixture to a 250 cm3 conical flask.

Question 13

Haber process conditions

Answer 13

T= 450oC, P= 200 – 1000 atm, catalyst = iron

Question 14

haber process and methanol from CO2

Answer 14

Low temp gives good yield but slow rate:
compromise temp used
High pressure gives good yield and high rate: too
high a pressure would lead to too high energy costs
for pumps to produce the pressure

Question 15

co to methanol

Answer 15

T= 400oC, P= 50 atm, catalyst = chromium and zinc

oxides

Question 16

contact process

Answer 16

T= 450oC, P= 1 or 2 atm, catalyst = V2O5
Low temp gives good yield but slow rate: compromise moderate temp used
High pressure only gives slightly better yield and high rate: too high a pressure would lead to too high energy costs for pumps to produce the pressure

Question 17

hydration of ethene

Answer 17

Low temp gives good yield but slow rate: compromise temp used
High pressure gives good yield and high rate: too high a pressure would lead to too high energy costs for pumps to produce the pressure
High pressure also leads to unwanted polymerisation of ethene to poly(ethene)

Question 18

condition of hydration of ethene

Answer 18

T= 300oC, P= 70 atm, catalyst = conc H3PO4

Question 19

catalyst in the reaction

Answer 19

In all cases catalysts speeds up the rate, allowing a lower temp to be used (and hence lower energy costs), but have no effect on position of equilibrium

Question 20

high pressure equipment

Answer 20

In all cases high pressure leads to too high energy costs for pumps to produce the pressure and too high
equipment costs to have equipment that can withstand high pressures.