A 10.0-g sample of C2H5OH is burned completely in air. How many molecules of H2O are formed?
3.92×1023
*How many grams are formed?*
did anyone figure out how to get the grams of H2O formed?
start by defining the reaction:
C2H5OH + 3O2 = 2CO2 + 3H2O
Now you know that each mole of C2H5OH produces 3 moles of H2O.
convert grams C2H5OH to moles, multiply by 3, and convert moles H2O to grams.
Well, it seems you're in need of some water-weight calculations! To determine the grams of H2O formed, we can use the molar mass of water, which is approximately 18 grams per mole. Considering that you have 3.92×10^23 molecules of H2O, let's put on our math circus hats and get to work!
First, we convert the number of molecules to moles by dividing by Avogadro's number (6.022×10^23). So, (3.92×10^23 molecules) / (6.022×10^23 molecules/mole) ≈ 0.65 moles of H2O.
Next, we can use the molar mass of water to find the grams. Multiply the number of moles (0.65 moles) by the molar mass of water (18 grams/mole), and voila! The answer floats right in front of us.
0.65 moles × 18 grams/mole ≈ 11.7 grams of H2O.
So, after a weighty endeavor with some mole-y math, we found that approximately 11.7 grams of water are formed when burning that 10.0-g sample of C2H5OH. *Ta-da!*
To determine the number of grams of H2O formed, we need to calculate the mole ratio of C2H5OH to H2O and then convert it to grams. Here's how you can do it step-by-step:
1. Find the molar mass of C2H5OH:
- C: 12.01 g/mol * 2 = 24.02 g/mol
- H: 1.01 g/mol * 6 = 6.06 g/mol
- O: 16.00 g/mol * 1 = 16.00 g/mol
Total molar mass = 24.02 g/mol + 6.06 g/mol + 16.00 g/mol = 46.08 g/mol
2. Calculate the number of moles of C2H5OH:
Mass of C2H5OH = 10.0 g
Moles of C2H5OH = Mass / Molar mass = 10.0 g / 46.08 g/mol = 0.217 mol
3. Use the balanced chemical equation to determine the mole ratio between C2H5OH and H2O:
C2H5OH + O2 -> CO2 + H2O
From the equation, we can see that one mole of C2H5OH reacts to form one mole of H2O.
4. Calculate the number of moles of H2O formed:
Moles of H2O = Moles of C2H5OH = 0.217 mol
5. Convert the moles of H2O to grams:
Molar mass of H2O = 2 * 1.01 g/mol + 16.00 g/mol = 18.02 g/mol
Mass of H2O = Moles of H2O * Molar mass of H2O = 0.217 mol * 18.02 g/mol = 3.91 g
Therefore, the mass of H2O formed is approximately 3.91 grams.
To calculate the number of grams of H2O formed, we'll first need to determine the number of moles of C2H5OH that were burned, and then use the mole ratio between C2H5OH and H2O to find the moles of H2O formed. Finally, we can convert the moles of H2O into grams using the molar mass of H2O.
1. Find the number of moles of C2H5OH:
We have a 10.0-g sample of C2H5OH. To determine the number of moles, we'll divide the mass by the molar mass of C2H5OH. The molar mass of C2H5OH is calculated by adding up the atomic masses of each element: 2 (C) + 6 (H) + 1 (O) = 46.07 g/mol.
Number of moles of C2H5OH = 10.0 g / 46.07 g/mol ≈ 0.217 mol (rounded to three decimal places)
2. Determine the moles of H2O formed:
According to the balanced chemical equation of the combustion reaction, one mole of C2H5OH reacts to produce 2 moles of H2O. Therefore, the moles of H2O formed will be twice the moles of C2H5OH.
Moles of H2O formed = 0.217 mol (C2H5OH) × 2 = 0.434 mol
3. Convert moles of H2O to grams:
The molar mass of H2O is calculated by adding up the atomic masses of hydrogen and oxygen: 2 (H) + 1 (O) = 18.02 g/mol.
Mass of H2O formed = 0.434 mol (H2O) × 18.02 g/mol = 7.82 g (rounded to two decimal places)
Therefore, the grams of H2O formed in the combustion of the 10.0-g sample of C2H5OH is approximately 7.82 g.