For the following reaction, 9.91 grams of sulfur are allowed to react with 20.8 grams of carbon monoxide .
sulfur(s) + carbon monoxide(g) sulfur dioxide(g) + carbon(s)
is the maximum amount of sulfur dioxide that can be formed?
What is the FORMULA for the limiting reagent?
What amount of the excess reagent remains after the reaction is complete?
S + 2CO ==> SO2 + 2C
mols S = grams/molar mass = ?
mols CO = grams/molar mass = ?
Using the coefficients in the balanced equation, convert mols S to mols SO2.
Do the same for mols CO to mols SO2.
It is likely that these two values for mols SO2 will not agree which means one is not right; the correct value in limiting (LR) reactions is always the smaller value and the reagent responsible for this is the LR (that will give you the formula for the LR). Then grams SO2 = mols SO2 x molar mass SO2.
For the excess reagent, use the coefficients in the balanced equation to convert mols LR to the excess reagent used up, then subtract initial amount of excess reagent - amount used up, and convert that to grams. Post your work if you get stuck.
To find the maximum amount of sulfur dioxide that can be formed, you need to determine the limiting reagent first. The limiting reagent is the reactant that is completely consumed and limits the amount of product that can be formed.
To determine the limiting reagent, you need to compare the amount of product that can be formed from each reactant. First, you need to convert the given masses of sulfur and carbon monoxide to moles using their respective molar masses.
1. Calculate the number of moles of sulfur:
Molar mass of sulfur = 32.07 g/mol
Number of moles of sulfur = mass of sulfur / molar mass of sulfur
2. Calculate the number of moles of carbon monoxide:
Molar mass of carbon monoxide = 28.01 g/mol
Number of moles of carbon monoxide = mass of carbon monoxide / molar mass of carbon monoxide
Next, you need to determine the stoichiometric ratio between the reactants and products.
Looking at the balanced equation:
sulfur + carbon monoxide → sulfur dioxide + carbon
1 mole + 1 mole → 1 mole + 1 mole
From the balanced equation, you can see that the stoichiometric ratio is 1:1 for both sulfur dioxide and carbon monoxide.
3. Compare the moles of both reactants:
- Divide the number of moles of sulfur by the stoichiometric coefficient of sulfur dioxide.
- Divide the number of moles of carbon monoxide by the stoichiometric coefficient of carbon monoxide.
The smaller result obtained will correspond to the limiting reagent.
Now that you have determined the limiting reagent, you can calculate the maximum amount of sulfur dioxide that can be formed using the coefficient from the balanced equation.
4. Calculate the maximum amount of sulfur dioxide formed:
Multiply the moles of the limiting reagent by the molar mass of sulfur dioxide to obtain the mass.
To find the formula for the limiting reagent, refer to the balanced equation. Since the stoichiometric coefficients of sulfur and carbon monoxide are both 1, both reactants will be used up completely, and there will be no excess reagent.
Therefore, the formula for the limiting reagent is the same as the chemical formula for sulfur, which is S.
As there is no excess reagent remaining after the reaction, the amount of excess reagent is zero.