Chemistry · p-Block (I) (Grp. 13, 14)

JEE Main 2024 — 5 April, Shift 1 — Question 76

The number of neutrons present in the more abundant isotope of boron is xx. Amorphous boron upon heating with air forms a product in which the oxidation state of boron is yy. The value of x+yx+y is:

  1. Option A:

    44

  2. Option B:

    66

  3. Option C:

    33

  4. Option D:

    99

    Correct

Answer: D

Step-by-step solution

The more abundant isotope of boron is 11B\mathrm{^{11}B}. Number of neutrons, x=11−5=6x = 11 - 5 = 6

On heating amorphous boron in air, we have

4B+3O2→2B2O3\mathrm{4B + 3O_2 \rightarrow 2B_2O_3}

Let oxidation state of boron = yy

2y+3(−2)=0⇒y=+32y + 3(-2) = 0 \Rightarrow y = +3

Thus, x+y=6+3=9x+y = 6+3 = 9 and the correct answer is Option D.

Answer key and solution verified before publishing.

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Exam
JEE Main 2024
Subject
Chemistry
Chapter
p-Block (I) (Grp. 13, 14)
Topic
Introduction & Properties of Group 13: Boron Family
The number of neutrons present in the more abundant isotope of boron… | JEE Main 2024 PYQ with Solution · DhiX AI