Question

The decomposition of $H_2{O}_2$ has a strong thermodynamic driving force
$2H_2{O}_2\to 2H_{2}O+O_2\left(g\right)\Delta H=-99kj/mole,\Delta s=+69J{K}^{-1}mol{e}^{-1}$
Addition of solution of KI causes $H_2{O}_2$ to decompose very rapidly as well
Step -1 (slow) $H_2{O}_2+l\to lO+H_{2}O$
Step -2 (fast) $H_2{O}_2+lO\to H_{2}O+r+O_2\left(g\right)$
Overall reaction: $2H_2{O}_2\to H_{2}O+O_2\left(g\right)$

The above experiment causes a big fluff of foam to spiral out of the beaker ( Elephant toothpaste reaction)
Identify the wrong statement.

• A. $H_2{O}_2$ is thermodynamically and kinetically unstable
• B. LO (aq) is the reaction intemediate
• C. the elephant tooth paste is hot to toch
• D. a glowing splint if plunged into the elephant toothpaste will catch fire

Answer 1

Answer: (A), (D)

$H_2{O}_2$ is thermodynamically and kinetically unstable
a glowing splint if plunged into the elephant toothpaste will catch fire

The statements (A) and (D) are the wrong statements.
(A)
The decomposition of $H_2{O}_2$ has a strong thermodynamic driving force.
Addition of solution of KI causes $H_2{O}_2$ to decompose very rapidly.
Hence, $H_2{O}_2$ is thermodynamically unstable and kinetically stable.
(B) IO (aq) is the reaction intermediate as it is formed in the first step and consumed in the second step.
(C) The elephant tooth paste is hot to touch as the decomposition of $H_2{O}_2$ is an exothermic reaction with negative value of enthalpy change.
(D) a glowing splint if plunged into the elephant toothpaste will not catch fire as along-with oxygen water is also present which will not support combustion.