JEE Main levelSingle correct optionDifficulty 2 of 3qa066
In the yellow precipitate (NHX4)X3[P(MoX3OX10)X4], the oxidation states of P and Mo respectively are
A+5 and +4
B+5 and +6
C+5 and +5
D+3 and +6
Answer: B
The unit MoX3OX10 carries charge −2 (3x−20=−2 gives x=+6). With four such units the anion charge is −8+nP=−3, so P is +5. The ammonium ions supply +3. Thus P is +5 and Mo is +6.