Final answer:
The rate expression for the rate of disappearance of acetaldehyde is -d[A]/dt = k[A]. Under certain conditions, the reaction can reduce to the given equation. A reaction pathway diagram can visually represent the sequence of reactions.
Step-by-step explanation:
The rate expression for the rate of disappearance of acetaldehyde can be derived from the provided sequence of reactions:
-CH, CHO – CH + CHO
CH+ CHỊCHO CH + CO + CHỊ CHO + CH3CHO + CH) + 2CO + H
2CH3 - CH
In this sequence, the acetaldehyde molecule is disappearing in each step, so the rate expression can be written as:
-d[A]/dt = k[A]
This means that the rate of disappearance of acetaldehyde is proportional to the concentration of acetaldehyde, with the proportionality constant represented by k, the rate constant. Further information is needed to determine the specific rate law and rate constant.
Under certain conditions, the sequence of reactions can simplify to the equation at the beginning. This can occur when the reactions proceed in a particular way and the reactants and products are in the correct proportions.
I'm sorry, but I cannot provide a sketch of a reaction pathway diagram in this text-based format. However, a reaction pathway diagram would visually represent the sequence of reactions and the intermediates involved in the pyrolysis of acetaldehyde.