JEE Main201815 Apr 2018Evening ShiftChemistrySome Basic Concepts of ChemistryActual
For per gram of reactant, the maximum quantity of N ₂ gas is produced in which of the following thermal decomposition reactions? (Given: Atomic wt. : Cr =52 u , Ba =137 u ).
Options
- ABa ( N ₃ )₂ (s) Ba ( C )+3 ~N ₂( ~g )
- B( NH ₄ )₂ Cr ₂ O ₇( ~s ) N ₂( ~g )+4 H ₂ O ( g )+ Cr ₂ O ₃( ~s )
- C2 NH ₃( ~g ) N ₂( ~g )+3 H ₂( ~g )
- D2 NH ₄ NO ₃( ~s ) 2 ~N ₂( ~g )+4 H ₂ O ( g )+ O ₂( ~g )
Correct answer
C. 2 NH ₃( ~g ) N ₂( ~g )+3 H ₂( ~g )
Step-by-step solution
(a) Molar mass of Ba ( N ₃ )₂( ~s )=221 ~g / mol 1 mole of Ba ( N ₃ )₂( ~s ) will give 3 moles of N ₂ hence 1 ~g 221 ~g / mol moles of Ba ( N ₃ )₂( ~s ) will give 3 1 221 =0.014 moles of N ₂ (b) Molar mass of ( NH ₄ )₂ Cr ₂ O ₇=252 ~g / mol . 1 mole of ( NH ₄ )₂ Cr ₂ O ₇ will give 1 mole of N ₂ hence 1 ~g 252 ~g / mol moles of ( NH ₄ )₂ Cr ₂ O ₇ will give 1 1 252 =0.0039 moles of N ₂ (c) Molar mass of NH ₃=17 ~g / mol . 2 mole of NH ₃ will give 1 mole of N ₂ hence 1 ~g 17 ~g / mol moles of NH ₃ will give 1 2 17 =0.