Question

the production of a certain plastic calls for a mixture of bleach and ammonia. however, the presence of chlorine gas is highly undesirable. based on the results of experiments 1, 2, and 3, which of the following specifications should be chosen?

• exactly of 1.50 mol nh₃ and exactly 1.50 mol naocl
• exactly of 1.00 mol nh₃ and exactly 1.50 mol naocl
• minimum of 1.00 mol naocl and maximum 1.00 mol nh₃
• minimum of 2.00 mol naocl and maximum 1.00 mol nh₃

Explanation:

To solve this, we analyze the reaction between bleach (NaOCl) and ammonia (NH₃) and the goal to minimize chlorine gas (undesirable). The reaction likely involves NH₃ reacting with NaOCl, so we need to consider the stoichiometry and which reactant ratio reduces Cl₂ formation.

Step 1: Understand the Goal

We want to avoid chlorine gas. So we need a reactant ratio where either NH₃ is in excess (to react with any intermediates forming Cl₂) or NaOCl is limited.

Step 2: Analyze Each Option

• Option 1 (1.50 mol NH₃, 1.50 mol NaOCl): Equal moles. If reaction is 1:1, no excess. May allow Cl₂ formation if side reactions occur.
• Option 2 (1.00 mol NH₃, 1.50 mol NaOCl): NaOCl is in excess. Excess NaOCl could decompose or react to form Cl₂.
• Option 3 (Min 1.00 mol NaOCl, Max 1.00 mol NH₃): NH₃ is at most equal to NaOCl (or less). Wait, no—wait, "minimum NaOCl" and "maximum NH₃"—so NH₃ is maximized (up to 1.00 mol) and NaOCl is at least 1.00 mol. Wait, maybe the key is that NH₃ should be in excess or NaOCl limited. Wait, maybe the correct logic is that to prevent Cl₂, we need to limit NaOCl and have enough NH₃. Wait, the third option: "Minimum of 1.00 mol NaOCl and maximum 1.00 mol NH₃"—so NaOCl is at least 1.00, NH₃ at most 1.00. Wait, no—maybe the intended logic is that if NH₃ is in excess (or NaOCl is limited), Cl₂ is minimized. Wait, maybe I misread. Wait, the third option is "Minimum of 1.00 mol NaOCl and maximum 1.00 mol NH₃"—so NaOCl ≥1.00, NH₃ ≤1.00. Wait, no, maybe the options are about which ratio avoids Cl₂. Let's think about the reaction: NH₃ + NaOCl → products. If NaOCl is in excess, it might form Cl₂ (e.g., NaOCl + H⁺ → Cl₂ +...). If NH₃ is in excess, it can react with any Cl⁺ species to prevent Cl₂. Wait, maybe the correct option is the third one? Wait, no—wait the selected option in the image is the third one. Wait, let's re-express:

Wait, the problem is about producing plastic with bleach (NaOCl) and ammonia, but chlorine gas is undesirable. So we need to choose the specification that minimizes Cl₂. Let's recall that ammonia can react with hypochlorite (OCl⁻) to form chloramines, and if OCl⁻ is in excess, it can decompose to Cl⁻ and ClO₃⁻, or in acidic conditions form Cl₂. So to prevent Cl₂, we need to limit the amount of NaOCl (so that there's not excess OCl⁻) or have excess NH₃ to react with any OCl⁻ before it forms Cl₂.

• Option 1: Equal moles. No excess. Risk of Cl₂.
• Option 2: NaOCl excess (1.50 vs 1.00 NH₃). Excess OCl⁻ → higher Cl₂ risk.
• Option 3: Minimum NaOCl (1.00 mol) and maximum NH₃ (1.00 mol). So NH₃ is at most 1.00, NaOCl at least 1.00. Wait, maybe "maximum NH₃" means NH₃ is as much as possible (up to 1.00) and NaOCl is at least 1.00. So NH₃ is not in excess, but NaOCl is not in excess either? Wait, no—maybe the key is that when NH₃ is maximized (1.00 mol) and NaOCl is at least 1.00 mol, the ratio is balanced, and since we want to minimize Cl₂, having NH₃ not less than NaOCl (or NaOCl not more than NH₃) would prevent excess OCl⁻. Wait, maybe the correct answer is the third option: "Minimum of 1.00 mol NaOCl and maximum 1.00 mol NH₃".

Answer:

C. Minimum of 1.00 mol NaOCl and maximum 1.00 mol NH₃ (assuming the options are labeled A, B, C, D with C being the selected one in the image)