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JEE Main levelOne or more correct optionsDifficulty 2 of 3qa152

Select all correct statements about the ring test for borate (boric acid) and the confirmatory tests.

  1. ATurmeric paper dipped in acidified boric acid solution and dried turns red-brown.
  2. BTriethyl borate, formed with ethanol and conc. , burns with a green-edged flame.
  3. CThe red-brown paper turns dark greenish-black when moistened with NaOH.
  4. DThe green colour of the flame is due to copper impurity in the reagents.

Answer: A, B, C

Boric acid turns turmeric red-brown and alkali changes this to dark greenish-black. with conc. as dehydrating agent, and the ester burns with a green-edged flame characteristic of boron. The last statement is false.
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