Steady-state material balance concept check: For complete combustion of 1 kg·mol carbon with 1 kg·mol oxygen to yield 1 kg·mol carbon dioxide in a steady-state reactor, what is the accumulation (in kg·mol)?

Introduction / Context:
Steady-state mass balances are a cornerstone of chemical engineering calculations. They underpin reactor design, process control, and safety analyses. This question evaluates whether you recognise that at steady state, the accumulation term in the general balance is zero.

Given Data / Assumptions:

• Reaction: C + O2 → CO2 (complete combustion).
• Molar flow basis: 1 kg·mol C and 1 kg·mol O2 feed; 1 kg·mol CO2 product.
• System is at steady state (time-invariant inventories).

Concept / Approach:
The general material balance is: Accumulation = In − Out + Generation − Consumption. At steady state, inventories do not change with time; thus Accumulation = 0 for each conserved quantity (overall and for non-reacting species). Reaction stoichiometry affects generation/consumption terms, not the steady-state accumulation term.

Step-by-Step Solution:

Verification / Alternative check:
If the reactor were transient (start-up/shutdown), accumulation would not be zero. The steady-state qualifier is decisive here.

Why Other Options Are Wrong:

• 1, 16, 44: These resemble stoichiometric molar amounts or molecular weights but do not represent an accumulation term at steady state.

Common Pitfalls:
Confusing “generation/consumption” with “accumulation.” Even with strong reaction rates, steady state means constant inventory, hence zero accumulation.

Final Answer:
0