For the elementary reaction, 3H_2g+N_2g→2NH_3g identify the correct relation among the following relations:

Q30 / 150 · MHT CET 2019 (Shift 1) · Chemistry

For the elementary reaction, $3 H_{2} (g) + N_{2} (g) \to 2 N H_{3} (g)$ identify the correct relation among the following relations:

A
$\frac{- 3}{2} \frac{d [H_{2} (g)]}{d t} = \frac{d [N H_{3} (g)]}{d t}$
Correct answer
B
$\frac{- 2}{3} \frac{d [H_{2} (g)]}{d t} = \frac{d [N H_{3} (g)]}{d t}$
C
$\frac{d [N H_{3} (g)]}{d t} = \frac{- 1}{3} \frac{d [H_{2} (g)]}{d t}$
D
$\frac{- d [H_{2} (g)]}{d t} = \frac{d [N H_{3} (g)]}{d t}$

Key Idea

•

Rate of disappearance

= \frac{D e c r a s e i n c o n c e n t r a t i o n}{T i m e t a k e n}

•

Rate of appearance

= \frac{I n c r e a s e i n c o n c e n t r a t i o n}{T i m e t a k e n}

For elementary reaction,

3 H_{2} (g) + N_{2} (g) \to 2 N H_{3} (g)

Rate of reaction

= \frac{- 1}{3} \frac{d [H_{1}]}{d t} = \frac{- d N_{2} (g)}{d t}

= \frac{1}{2} \frac{N H_{3} (g)}{d t}

From the given options,

(B)

is correct.

- \frac{2}{3} \frac{d [H_{2} (g)]}{d t} = \frac{d [N H_{3} (g)]}{d t}

Hence, the correct answer is option: 'B'.