Core prac 4 - rates of hydrolysis of halogenoalkanes

Question 1

method

Answer 1

set up water bath in 250ml beaker with water around 50C
fil 3 test tubes with 5cm3 of ethanol. add four drops of each halogenoalkane to one of each test tube
loosely bung each test tube and place into water
pour 5cm3 of silver nitrate solution into 3 clean test tubes and place into water bath
once halo-eth solutions reach water bath temp add silver nitrate into them, replace bung and start stop watch
measure time taken for precipitate to form and solution cloudy.

Question 2

what other two halogenoalkanes do you use after the original three

Answer 2

1-bromobutane (repeat and primary)
2-bromobutane (secondary)
2-bromo-2-methylpropane (tertiary)

Question 3

safety

Answer 3

wear eye protection

halogenoalkane and ethanol flammable

Question 4

why dont use hydroxide ions as nucleophile

Answer 4

if hydroxide ions are used then forms silver hydroxide precipitate will form

Question 5

patterns shown in results

Answer 5

down group 7 the time to react decreases

tertiary halogenoalkanes take the shortest time to react, then secondary and slowest primary

Question 6

what are the original three compounds

Answer 6

1-chlorobutane
1-bromobutane
1-iodobutane