How to Calculate Efficiency in Chemical Reactions

How can we calculate the efficiency of a chemical reaction?

Given the data when silicon dioxide combines with carbon in the following reaction, it is only 95.2% efficient. What mass of silicon carbide will form when 5.75g of silicon dioxide reacts?

Answer

The efficiency of a chemical reaction can be calculated by comparing the actual yield to the theoretical yield. In this case, the efficiency is stated as 95.2%. The mass of silicon carbide that will form when 5.75g of silicon dioxide reacts, considering the 95.2% efficiency, is 3.67g.

Efficiency in chemical reactions is a crucial concept that helps determine the actual yield produced compared to the theoretical yield that could be obtained under ideal conditions. In the given data, the efficiency of the reaction between silicon dioxide and carbon is specified at 95.2%.

To calculate the mass of silicon carbide that will form when 5.75g of silicon dioxide reacts, we first need to determine the number of moles of silicon dioxide and silicon carbide involved in the reaction.

The balanced chemical equation for the reaction is: SiO₂ + 3C → SiC + 2CO

Given that the mole ratio of SiO₂ and SiC is 1:1, we can proceed with the calculation:

First, calculate the number of moles of SiO₂:

Number of moles of SiO₂ = 5.75g / 60.08 g/mol = 0.096 mol

Since the mole ratio of SiO₂ and SiC is 1:1, the number of moles of SiC will also be 0.096 mol.

Next, determine the mass of SiC produced at 100% efficiency:

Mass of SiC = 0.096 mol × 40.11 g/mol = 3.85 g

However, since the reaction is only 95.2% efficient, we need to adjust the mass of SiC accordingly:

Mass of SiC at 95.2% efficiency = (3.85g / 100) × 95.2 = 3.67g

Therefore, when 5.75g of silicon dioxide reacts with carbon in the given reaction, 3.67g of silicon carbide will form at 95.2% efficiency.