"What mass of silicon carbide should result when 100.00g of silicon dioxide reacts with excess 100.00g of carbon?"

SiO2 + 3 C = 2 CO + SiC (balanced)

Direct question from homework; I was wondering if someone could explain how to find the solution with limiting reactants. A step-by-step would be helpful.

The problem states that the 100 g C is an excess; therefore, this is not a limiting reagent problem, assuming that statement is correct. Therefore, it's worked as a simple stoichiometry problem.

To solve this problem using the concept of limiting reactants, you need to determine which reactant is the limiting reactant and then calculate the mass of the desired product, silicon carbide (SiC).

Step 1: Write the balanced equation for the reaction.
The balanced equation is already given: SiO2 + 3 C = 2 CO + SiC.

Step 2: Calculate the molar mass of silicon dioxide (SiO2) and carbon (C).
The molar mass of SiO2 is calculated by adding the atomic masses of silicon (Si) and two oxygen (O) atoms: 28.086 g/mol + (2 × 16.00 g/mol) = 60.08 g/mol.
The molar mass of carbon is calculated by adding the atomic mass of carbon (C): 12.01 g/mol.

Step 3: Convert the masses of silicon dioxide and carbon to moles using their molar masses.
Number of moles of SiO2 = mass of SiO2 / molar mass of SiO2.
Number of moles of SiO2 = 100.00 g / 60.08 g/mol = 1.665 mol.
Number of moles of carbon = mass of carbon / molar mass of carbon.
Number of moles of carbon = 100.00 g / 12.01 g/mol = 8.33 mol.

Step 4: Determine the stoichiometric ratio between silicon dioxide and silicon carbide from the balanced equation.
The stoichiometric ratio is 1 mole of SiO2 reacts with 1 mole of SiC.

Step 5: Compare the moles of silicon dioxide and carbon.
Since the stoichiometric ratio is 1:1 between SiO2 and SiC, the limiting reactant is the one with fewer moles, which is SiO2 (1.665 mol).

Step 6: Calculate the moles of silicon carbide formed.
Since the balanced equation shows that 1 mole of SiO2 reacts to form 1 mole of SiC, the moles of SiC formed will be equal to the moles of SiO2 used.

Step 7: Convert the moles of silicon carbide to grams using its molar mass.
Mass of SiC = moles of SiC × molar mass of SiC.
Mass of SiC = 1.665 mol × (28.09 g/mol) = 46.70 g.

Therefore, the mass of silicon carbide that should result from the reaction is 46.70 grams.