C16 P2

Question 1

Explain whether the first method or the second method of production of phosphoric acid has higher atomic economy

Answer 1

Method 1 as its the only product

Question 2

By considering both rate and yield, why the reaction is carried out at a temperature of 300oC rather than at a higher temperature

Answer 2

Rate would decrease because E>Ea
Chosen T is a compromise

Question 3

On an industrial scale ethanol can be produced from ethene by direct hydration or from glucose by fermentation
State the conditions for the direct hydration reaction
State two advantages an two disadvantages of the fermentation method compared with the direct hydration method

Answer 3

Hot concentrated H3PO4
Fermentation -
Low energy use
Less fossil fuel use
Lower equipment costs

Slower
Impure product
Low atom economy

Question 4

Suggest why lidocaine hydrochloride is used medically in preference to lidocaine

Answer 4

Salt is ionic and soluble

Question 5

Suggest why inital rates of reaction are used to determine these orders rather than rates of reaction at other times during the experiments

Answer 5

Concentration are known

Question 6

State how the initial rate is obtained from a graph o the concentration of the product against time

Answer 6

Gradient at t=0

Question 7

Suggest why the order with respect to iodine is zero

Answer 7

Slowest/ limiting step