JEE Advanced levelSingle correct optionDifficulty 3 of 3pn012
Arrange the following in increasing order of the oxidation state of nitrogen: NHX3, NX2HX4, NHX2OH, HNX3 and NOX2X−.
ANHX3<NX2HX4<NHX2OH<HNX3<NOX2X−
BNHX3<HNX3<NX2HX4<NHX2OH<NOX2X−
CNHX3<NX2HX4<HNX3<NHX2OH<NOX2X−
DNX2HX4<NHX3<NHX2OH<HNX3<NOX2X−
Answer: A
Taking H as +1 and O as -2: NHX3 gives -3; NX2HX4 gives 2x+4=0, so -2; NHX2OH gives x+3−2=0, so -1; HNX3 gives 3x+1=0, so average -1/3; NOX2X− gives x−4=−1, so +3. The order is -3 < -2 < -1 < -1/3 < +3.