20ml CO was mixed with 50 ml of oxygen and the mixture was exploded. On cooling, the resulting mixture was shaken with KOH. Find the final gaseous volume

Options

A. 20 ml
B. 30 ml
C. 40 ml
D. 10 ml

Answer

To solve the problem step by step, we will analyze the reaction between carbon monoxide (CO) and oxygen (O2) and determine the final gaseous volume after the reaction with potassium hydroxide (KOH).

### Step 1: Identify the Reaction
The reaction between carbon monoxide and oxygen can be represented as:
\[ 2 \text{CO} + \text{O}_2 \rightarrow 2 \text{CO}_2 \]

### Step 2: Determine the Initial Volumes
We are given:
- Volume of CO = 20 ml
- Volume of O2 = 50 ml

### Step 3: Determine the Limiting Reagent
From the balanced equation, 2 volumes of CO react with 1 volume of O2. Therefore, for 20 ml of CO:
- Required O2 = \( \frac{20 \text{ ml CO}}{2} = 10 \text{ ml O2} \)

Since we have 50 ml of O2 available, CO is the limiting reagent.

### Step 4: Calculate the Volume of O2 Reacted
Since 20 ml of CO will react with 10 ml of O2, the remaining volume of O2 after the reaction will be:
- Remaining O2 = Initial O2 - Reacted O2
- Remaining O2 = 50 ml - 10 ml = 40 ml

### Step 5: Calculate the Volume of CO2 Produced
According to the reaction, 2 volumes of CO produce 2 volumes of CO2. Therefore, the volume of CO2 produced from 20 ml of CO is:
- Volume of CO2 = 20 ml

### Step 6: Reaction of CO2 with KOH
The reaction of CO2 with KOH can be represented as:
\[ \text{CO}_2 + 2 \text{KOH} \rightarrow \text{K}_2\text{CO}_3 + \text{H}_2\text{O} \]

From the stoichiometry of this reaction, 1 volume of CO2 will react with 2 volumes of KOH. However, we only need to consider the gaseous products.

### Step 7: Determine the Final Gaseous Volume
Since all of the CO2 produced (20 ml) will react with KOH, it will be completely consumed. Therefore, after the reaction, the only gas remaining will be the unreacted O2.

Final gaseous volume:
- Remaining O2 = 40 ml

Thus, the final gaseous volume after the reaction with KOH is **40 ml**.

### Summary of the Steps:
1. Identify the reaction and write the balanced equation.
2. Determine the initial volumes of CO and O2.
3. Identify the limiting reagent (CO).
4. Calculate the volume of O2 that reacts.
5. Calculate the volume of CO2 produced.
6. Determine the reaction of CO2 with KOH.
7. Calculate the final gaseous volume.