A chemist mixes 5.216 g of potassium permanganate, 2.318 g of ethanol, and excess sulfuric acid. These chemicals react as follows:
4 KMnO4 + 5 C2H5OH + 6 H2SO4 ---> 4 MnSO4 + 5 CH3COOH + 2 K2SO4 + 11 H20
What mass of sulfuric acid is consumed in this reaction, assuming that the reaction goes to completion?
mols KMnO4 = grams/molar mass = approx 0.033 but you need to this and all of the calculations that follow more accurately.
mols ethanol = approx 0.05
Convert mols KMnO4 to mols H2SO4. That's 0.033 x 6/4 = 0.05
Convert mols ethanol to mols H2SO4. That's 0.05 x 6/5 = 0.06
The limiting reagent is KMnO4 and you will use approx 0.05 mols H2SO4
Then convert mols H2SO4 to grams. g = mols x molar mass.
Check my work.
I got 4.854 g of H2SO4. Thank you so much.
I did it right the first time just has trouble understanding the problem in my head.
To find grams of excess reactant I just have to convert moles of ethanol to g right?
excess mol ethanol x molar mass ethanol = grams ethanol in excess
To find the mass of sulfuric acid consumed in this reaction, we need to use the stoichiometry of the reaction. The stoichiometry tells us the molar ratio between the reactants and products involved in the reaction.
In this case, the balanced chemical equation is:
4 KMnO4 + 5 C2H5OH + 6 H2SO4 ---> 4 MnSO4 + 5 CH3COOH + 2 K2SO4 + 11 H2O
From this balanced equation, we can see that for every 4 moles of KMnO4 reactant used, 6 moles of H2SO4 are consumed. Therefore, the molar ratio between KMnO4 and H2SO4 is 4:6, or simply 2:3.
To find the moles of H2SO4 consumed, we need to convert the mass of KMnO4 to moles, assuming it is the limiting reactant, and then use the mole ratio.
Step 1: Calculate the moles of KMnO4
Molar mass of KMnO4 = (39.10 g/mol) + (54.94 g/mol) + (16.00 g/mol * 4) = 158.03 g/mol
Moles of KMnO4 = Mass of KMnO4 / Molar mass of KMnO4
Moles of KMnO4 = 5.216 g / 158.03 g/mol
Step 2: Calculate the moles of H2SO4
Moles of H2SO4 = (2/3) * Moles of KMnO4
Step 3: Calculate the mass of H2SO4 consumed
Mass of H2SO4 = Moles of H2SO4 * Molar mass of H2SO4
Now we can perform these calculations:
Moles of KMnO4 = 5.216 g / 158.03 g/mol
Moles of H2SO4 = (2/3) * Moles of KMnO4
Molar mass of H2SO4 = (1.01 g/mol * 2) + (32.07 g/mol) + (16.00 g/mol * 4)
Mass of H2SO4 = Moles of H2SO4 * Molar mass of H2SO4
By plugging in the values, we can calculate the mass of sulfuric acid consumed in this reaction.