Question

Which salts are used to determine nitrogen from urea by biuret -Spectrophotometrically
Options
O
Copper salts
Iron salts
O nickel salts
O zinc salt
Clear Response​

Answer 1

sulphuric acid and a little amount of potassium sulphate and copper sulphate. Heat the flask to evaporate the water and to digest the biuret. After digestion, determine the nitrogen by micro- distillation method

Answer 2

Explanation:

Biuret is an impurity in urea fertilizer caused by a side reaction at higher temperatures during processing. It has been identified as injurious to citrus foliage and to certain germinating seeds. The earliest urea plant designs produced urea with up to five percent biuret. ex

Given Urea= NH2- CO- NH2 And we know that Total mass of urea = 60 Mass of nitrogen = 14 Two molecules of nitrogen= 2*14= 28 Percentage of nitrogen = Mass of Nitrogen/(Urea ) x 100 = 28/60 x 100 = 46.6% Hence Percentage of nitrogen in urea is 46% Option A is the right answer.