Question

When 3.0 g of carbon is burnt in 8.00 g oxygen, 11.00 g of carbon dioxide is produced. What mass of carbon dioxide will be formed when 3.00 g of carbon is burnt in 50.00 g of oxygen? Which law of chemical combinations will govern your answer?

Answer 1

Step 1: Given Information:

• $3.0\mathrm{g}$ of carbon is burnt in $8.00\mathrm{g}$ oxygen, and $11.00\mathrm{g}$ of carbon dioxide is produced.
• The total mass of the reactant is equal to the total mass of the product, this satisfies the law of definite proportions.

Step 2: Reaction for the formation of Carbon dioxide:

• The reaction for the formation of carbon dioxide is depicted as:

$$\begin{gathered} \mathrm{C}\left(\mathrm{s}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right)\to {\mathrm{CO}}_2\left(\mathrm{g}\right) \\ 3\mathrm{g}8.00\mathrm{g}11.00\mathrm{g} \end{gathered}$$

Step 3: Calculation for the mass of carbon dioxide:

$$\begin{gathered} \mathrm{C}\left(\mathrm{s}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right)\to {\mathrm{CO}}_2\left(\mathrm{g}\right) \\ 3\mathrm{g}50.0\mathrm{g}? \end{gathered}$$

When $3.0\mathrm{g}$ of carbon reacts with $8.00\mathrm{g}$ of oxygen then $11.00\mathrm{g}$ of carbon dioxide is produced.

So, the mass of leftover oxygen is:

$\mathrm{Mass}\mathrm{of}\mathrm{left}\mathrm{over}\mathrm{oxygen}=(50.0\mathrm{g}-8.00\mathrm{g})=42\mathrm{g}$

In this case, also, only $11.00\mathrm{g}$ of carbon dioxide will be formed