A certain volume of CO2 is passed over red hot coke then it gives 700 dm3 of CO and 50 dm3 of CO2 .calculate the initial volume of CO2 passed over red hot coke

To determine the initial volume of carbon dioxide (CO2) that was passed over red hot coke, we can use the principles of stoichiometry and the conservation of mass. The reaction between carbon dioxide and coke (which is primarily carbon) produces carbon monoxide (CO) and carbon dioxide. The balanced chemical equation for this reaction can be represented as follows:

The Reaction Equation

The reaction can be simplified to:

• CO2 + C → 2CO

This equation tells us that one molecule of carbon dioxide reacts with one molecule of carbon (from coke) to produce two molecules of carbon monoxide. In terms of volumes, since gases at the same temperature and pressure occupy volumes that are proportional to the number of moles, we can apply this directly to volumes.

Volume Relationships

From the reaction, we see that:

• 1 volume of CO2 produces 2 volumes of CO.

In your case, we know that the reaction produces 700 dm³ of CO and 50 dm³ of CO2. However, the 50 dm³ of CO2 is actually a product of the reaction, not the initial reactant. Therefore, we need to find out how much CO2 was initially present before the reaction took place.

Calculating Initial Volume of CO2

Let’s denote the initial volume of CO2 that was passed over the coke as V. According to the stoichiometry of the reaction:

• For every 1 volume of CO2 that reacts, 2 volumes of CO are produced.

Since we produced 700 dm³ of CO, we can set up the following relationship:

• V (initial CO2) - 50 dm³ (produced CO2) = 700 dm³ (produced CO)

From the balanced equation, we know that the volume of CO produced is twice the volume of CO2 that reacted. Therefore, we can express this as:

• V - 50 = 700/2

Now, simplifying this gives:

• V - 50 = 350
• V = 350 + 50
• V = 400 dm³

Final Result

The initial volume of CO2 that was passed over the red hot coke is therefore 400 dm³.

This calculation illustrates how stoichiometric relationships in chemical reactions can help us deduce the amounts of reactants and products involved. By understanding the ratios in which substances react, we can solve for unknown quantities effectively.