JEE Exam  >  JEE Questions  >  The incorrect statement is :a)Cu2+ ion gives ... Start Learning for Free
The incorrect statement is :
  • a)
    Cu2+ ion gives chocolate coloured precipitate with potassium ferrocyanide solution
  • b)
    Cu2+ and Ni2+ ions give black precipitate with H2S in presence of HCl solution
  • c)
    Ferric ion gives blood red colour with potassium thiocyanate
  • d)
    Cu2+ salts give red coloured borax bead test in reducing flame
Correct answer is option 'B'. Can you explain this answer?
Verified Answer
The incorrect statement is :a)Cu2+ ion gives chocolate coloured precip...
Due to common ion effect, sufficient S2– concentration is not produced and no ppt formed of NiS.
View all questions of this test
Most Upvoted Answer
The incorrect statement is :a)Cu2+ ion gives chocolate coloured precip...
Incorrect statement: Cu2 and Ni2 ions give black precipitate with H2S in presence of HCl solution.

Explanation:

Cu2 ions give a black precipitate with H2S in the presence of HCl solution, but Ni2 ions give a green precipitate. Therefore, the statement is incorrect.

Explanation in detail:

Cu2 ion gives chocolate coloured precipitate with potassium ferrocyanide solution:

When potassium ferrocyanide solution is added to a solution containing Cu2 ion, a chocolate-brown precipitate of copper ferrocyanide is formed.

Cu2+ + K4[Fe(CN)6] → Cu2[Fe(CN)6]↓ + 4K+

Cu2 and Ni2 ions give black precipitate with H2S in presence of HCl solution:

When hydrogen sulfide gas is passed through a solution containing Cu2 ion in the presence of HCl solution, a black precipitate of CuS is formed. However, when the same procedure is carried out with Ni2 ions, a green precipitate of NiS is formed. Therefore, the statement is incorrect.

2Cu2+ + H2S → Cu2S↓ + 2H+

Ni2+ + H2S → NiS↓ + 2H+

Ferric ion gives blood red colour with potassium thiocyanate:

When potassium thiocyanate solution is added to a solution containing ferric ion, a blood-red colour is obtained due to the formation of ferric thiocyanate complex.

Fe3+ + 3SCN- → Fe(SCN)3↓

Cu2 salts give red coloured borax bead test in reducing flame:

Copper compounds give a characteristic red colour to the borax bead in a reducing flame due to the formation of copper oxide.

Cu2+ + CuO + Na2B4O7 → Na2[CuB4O7]↓ + O2

Therefore, option B is incorrect.
Explore Courses for JEE exam
The incorrect statement is :a)Cu2+ ion gives chocolate coloured precipitate with potassium ferrocyanide solutionb)Cu2+ and Ni2+ ions give black precipitate with H2S in presence of HCl solutionc)Ferric ion gives blood red colour with potassium thiocyanated)Cu2+ salts give red coloured borax bead test in reducing flameCorrect answer is option 'B'. Can you explain this answer?
Question Description
The incorrect statement is :a)Cu2+ ion gives chocolate coloured precipitate with potassium ferrocyanide solutionb)Cu2+ and Ni2+ ions give black precipitate with H2S in presence of HCl solutionc)Ferric ion gives blood red colour with potassium thiocyanated)Cu2+ salts give red coloured borax bead test in reducing flameCorrect answer is option 'B'. Can you explain this answer? for JEE 2024 is part of JEE preparation. The Question and answers have been prepared according to the JEE exam syllabus. Information about The incorrect statement is :a)Cu2+ ion gives chocolate coloured precipitate with potassium ferrocyanide solutionb)Cu2+ and Ni2+ ions give black precipitate with H2S in presence of HCl solutionc)Ferric ion gives blood red colour with potassium thiocyanated)Cu2+ salts give red coloured borax bead test in reducing flameCorrect answer is option 'B'. Can you explain this answer? covers all topics & solutions for JEE 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for The incorrect statement is :a)Cu2+ ion gives chocolate coloured precipitate with potassium ferrocyanide solutionb)Cu2+ and Ni2+ ions give black precipitate with H2S in presence of HCl solutionc)Ferric ion gives blood red colour with potassium thiocyanated)Cu2+ salts give red coloured borax bead test in reducing flameCorrect answer is option 'B'. Can you explain this answer?.
Solutions for The incorrect statement is :a)Cu2+ ion gives chocolate coloured precipitate with potassium ferrocyanide solutionb)Cu2+ and Ni2+ ions give black precipitate with H2S in presence of HCl solutionc)Ferric ion gives blood red colour with potassium thiocyanated)Cu2+ salts give red coloured borax bead test in reducing flameCorrect answer is option 'B'. Can you explain this answer? in English & in Hindi are available as part of our courses for JEE. Download more important topics, notes, lectures and mock test series for JEE Exam by signing up for free.
Here you can find the meaning of The incorrect statement is :a)Cu2+ ion gives chocolate coloured precipitate with potassium ferrocyanide solutionb)Cu2+ and Ni2+ ions give black precipitate with H2S in presence of HCl solutionc)Ferric ion gives blood red colour with potassium thiocyanated)Cu2+ salts give red coloured borax bead test in reducing flameCorrect answer is option 'B'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of The incorrect statement is :a)Cu2+ ion gives chocolate coloured precipitate with potassium ferrocyanide solutionb)Cu2+ and Ni2+ ions give black precipitate with H2S in presence of HCl solutionc)Ferric ion gives blood red colour with potassium thiocyanated)Cu2+ salts give red coloured borax bead test in reducing flameCorrect answer is option 'B'. Can you explain this answer?, a detailed solution for The incorrect statement is :a)Cu2+ ion gives chocolate coloured precipitate with potassium ferrocyanide solutionb)Cu2+ and Ni2+ ions give black precipitate with H2S in presence of HCl solutionc)Ferric ion gives blood red colour with potassium thiocyanated)Cu2+ salts give red coloured borax bead test in reducing flameCorrect answer is option 'B'. Can you explain this answer? has been provided alongside types of The incorrect statement is :a)Cu2+ ion gives chocolate coloured precipitate with potassium ferrocyanide solutionb)Cu2+ and Ni2+ ions give black precipitate with H2S in presence of HCl solutionc)Ferric ion gives blood red colour with potassium thiocyanated)Cu2+ salts give red coloured borax bead test in reducing flameCorrect answer is option 'B'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice The incorrect statement is :a)Cu2+ ion gives chocolate coloured precipitate with potassium ferrocyanide solutionb)Cu2+ and Ni2+ ions give black precipitate with H2S in presence of HCl solutionc)Ferric ion gives blood red colour with potassium thiocyanated)Cu2+ salts give red coloured borax bead test in reducing flameCorrect answer is option 'B'. Can you explain this answer? tests, examples and also practice JEE tests.
Explore Courses for JEE exam

Top Courses for JEE

Explore Courses
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev