The combustion of ethanol, C2H5OH produces CO2 and H2O. The density of ethanol is 0.789 g/ml, oxygen is 1.43 g/L, and CO2 is 1.98 g/L. In one experiment 17.6 mL of ethanol were combined with 10.5 L O2 and allowed to react.
Determine the theoretical yield of CO2 in grams.
C2H5OH + 3O2 ==> 2CO2 + 3H2O
mols C2H5OH = 17.6 mL x 0.789 g/mL x (1 mol/46 g) = 0.3018
mols O2 = 10.5 L x 1.43 g/L x (1 mol/32 g) = 0.469
So you need 3 mols O2 for every 1 mol O2. Do you have that? 3*0.3018 = 0.905 g O2 but you don't have that so O2 must be the limiting reagent.
How much CO2 will that produce? That's 0.469 mols O2 x (2 mols CO2/3 mols O2) = 0.313 mols O2 and that x 44 = 13.8 grams CO2 = theoretical yield in grams.
oops! typo. Should be CO2 and not O2 in the last two lines.
That's 0.469 mols O2 x (2 mols CO2/3 mols O2) = 0.313 mols "CO2" and that x 44 = 13.8 grams CO2 = theoretical yield in grams.
To determine the theoretical yield of CO2 in grams, we first need to calculate the number of moles of ethanol and oxygen used in the reaction.
1. Calculate the number of moles of ethanol:
Given density of ethanol = 0.789 g/ml and volume = 17.6 mL
Mass of ethanol = density * volume = 0.789 g/ml * 17.6 ml = 13.8704 g
Molar mass of ethanol (C2H5OH) = (2 * Atomic mass of C) + (6 * Atomic mass of H) + (1 *Atomic mass of O)
= (2 * 12.01 g/mol) + (6 * 1.00784 g/mol) + (1 * 16.00 g/mol)
= 46.07 g/mol
Number of moles of ethanol = mass of ethanol / molar mass of ethanol
= 13.8704 g / 46.07 g/mol
= 0.301 mol
2. Calculate the number of moles of oxygen:
Given volume of oxygen (O2) = 10.5 L
The molar mass of oxygen (O2) is 16.00 g/mol.
Number of moles of oxygen = volume of oxygen / molar volume of oxygen
= 10.5 L / (1 L/mol)
= 10.5 mol
The balanced equation for the combustion of ethanol is:
C2H5OH + 3O2 -> 2CO2 + 3H2O
From the equation, we can see that for every 1 mole of ethanol, 2 moles of CO2 are produced.
3. Calculate the theoretical yield of CO2:
Number of moles of CO2 = 2 * Number of moles of ethanol
= 2 * 0.301 mol
= 0.602 mol
To convert moles of CO2 to grams, we use the molar mass of CO2, which is 44.01 g/mol.
Theoretical yield of CO2 = number of moles of CO2 * molar mass of CO2
= 0.602 mol * 44.01 g/mol
≈ 26.492 g
Therefore, the theoretical yield of CO2 in grams is approximately 26.492 g.