20 ml of CO is exploded with 30 ml of O_2 at constant temperature and pressure. Final volume of the gases in ml will be

Options

A. 35
B. 40
C. 50
D. 60

Answer

To solve the problem of determining the final volume of gases after the reaction between carbon monoxide (CO) and oxygen (O2), we can follow these steps:

### Step 1: Write the balanced chemical equation
The reaction between carbon monoxide and oxygen can be represented by the following balanced equation:
\[ 2 \text{CO} + \text{O}_2 \rightarrow 2 \text{CO}_2 \]

### Step 2: Identify the initial volumes of the gases
From the problem, we have:
- Volume of CO = 20 ml
- Volume of O2 = 30 ml

### Step 3: Determine the stoichiometric ratios
From the balanced equation, we see that:
- 2 volumes of CO react with 1 volume of O2.
- Therefore, 1 volume of CO requires 0.5 volumes of O2.

### Step 4: Calculate the amount of O2 needed for the given CO
For 20 ml of CO:
\[ \text{O}_2 \text{ needed} = \frac{20 \text{ ml CO}}{2} = 10 \text{ ml O}_2 \]

### Step 5: Identify the limiting reagent
Since we have 30 ml of O2 available and only 10 ml is required to react with 20 ml of CO, CO is the limiting reagent.

### Step 6: Calculate the remaining volume of O2 after the reaction
Since 10 ml of O2 is consumed:
\[ \text{Remaining O}_2 = 30 \text{ ml} - 10 \text{ ml} = 20 \text{ ml} \]

### Step 7: Calculate the volume of CO2 produced
According to the balanced equation, 2 volumes of CO produce 2 volumes of CO2. Therefore, 20 ml of CO will produce:
\[ \text{CO}_2 \text{ produced} = 20 \text{ ml} \]

### Step 8: Calculate the total volume of gases after the reaction
Now we can sum the volumes of the remaining gases:
- Remaining CO = 0 ml (all reacted)
- Remaining O2 = 20 ml
- Produced CO2 = 20 ml

Total volume of gases after the reaction:
\[ \text{Total Volume} = \text{Remaining CO} + \text{Remaining O}_2 + \text{Produced CO}_2 = 0 \text{ ml} + 20 \text{ ml} + 20 \text{ ml} = 40 \text{ ml} \]

### Final Answer
The final volume of the gases will be **40 ml**.

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