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Solutions

Question
CBSEENCH12010660

The ratio of masses of oxygen and nitrogen of a particular gaseous mixture is 1:4. The ratio of number of their molecule is

  • 1:4

  • 7:32

  • 1:8

  • 3:16

Solution

B.

7:32

straight n subscript straight O subscript 2 over straight n subscript straight N subscript 2 end subscript space equals space fraction numerator begin display style straight m subscript straight O subscript 2 end subscript over straight M subscript straight O subscript 2 end subscript end style over denominator begin display style straight m subscript straight N subscript 2 end subscript over straight M subscript straight N subscript 2 end subscript end style end fraction
where space straight m subscript straight O subscript 2 end subscript space equals space given space mass space of space straight O subscript 2
straight m subscript straight N subscript 2 end subscript space equals space given space mass space of space straight N subscript 2
straight M subscript straight O subscript 2 space end subscript space equals space molecular space mass space of space straight O subscript 2
straight M subscript straight N subscript 2 end subscript space equals space moleular space mass space space of space straight N subscript 2
straight n subscript straight O subscript 2 end subscript space equals space number space of space moles space of space straight O subscript 2
straight n subscript straight N subscript 2 space equals space end subscript Number space of space moles space of space straight N subscript 2
space equals space open square brackets straight m subscript straight O subscript 2 end subscript over straight m subscript straight N subscript 2 end subscript close square brackets 28 over 32 space equals space 1 fourth space straight x space 28 over 32 space equals space 7 over 32