Pharm Chem Lab

Question 1

Prescribed solution(arsenic compounds)+Hypophosphorus Reagent

Answer 1

Brown ppt is produced

Question 2

Solution(bromide)+Silver nitrate+ammonia

Answer 2

A curdy pale yellow ppt is produced
ppt dissolves with difficulty upon addition of ammonia

Question 3

Solution(chloride)+Nitric acid+Silver nitrate+Ammonia

Answer 3

A curdy white ppt is produced
ppt dissolves easily upon addition of ammonia

Question 4

Solution(iron)+Potassium hexacyanoferrate 3

Answer 4

Blue ppt which is insoluble in HCl

Question 5

Solution(iron)+HCl+Potassium thiocyanate

Answer 5

Red colour is discharged

Question 6

Solution (lead)+Acetic acid+Potassium chromate

Answer 6

A yellow ppt is produced which is soluble in sodium hydroxide

Question 7

Solution (lead) + Water +Acetic acid+Potassium iodide

Answer 7

Yellow ppt produced which when heated becomes glistering yellow plates

Question 8

Solution (sulphates) + HCl +Barium chloride

Answer 8

A white ppt is produced

Question 9

Schiff’s reagent+solution

Answer 9

Pink colouration produced
Carbonyls may be present

Question 10

Tollens reagent(ammonia+aqueous silver nitrate)+ solution

Answer 10

Silver mirror is formed on the walls of the test tube
Aldehydes may be present

Question 11

Fehling 1(copper sulphate solution)+Fehling 2(alkaline tartrate solution)+Solution+heat

Answer 11

Reddish brown ppt is formed
Aliphatic aldehydes may be present

Question 12

Potassium permanganate+solution

Answer 12

Decolourization with brown ppt formation (manganese dioxide)
Aldehydes may be present

Question 13

Solution+Sodium hydroxide+Iodide in Potassium iodide + heat

Answer 13

Pale finely divided ppt of iodoform forms
Ketones may be present
Exceptions:
Acetyladehyde may be present (if all tests are positive)
Secondary alcohol or ethanol may be present (if only iodoform rxn is positive)

Question 14

Lactone (cyclic esters)

Answer 14

Cyclic esters of organic acids

Question 15

Lactams(cyclic amides)

Answer 15

Cyclic amides derived from amino alkanoic acid

Question 16

Lactols(hemiacetal or hemiketal)

Answer 16

Formed from addition if hydroxyl group to carbonyl group

Question 17

Lactides

Answer 17

Lactone cyclic esters derived from multiple esterification