If a reaction was started with 3 mL of TEOS in H2O and yielded 0.3275 grams of SiO2. what is the percent recovery of SiO2?
1. What is the concentration of TEOS?
2.What is TEOS?
Si(OC2H5)4 + 2 H2O → SiO2 + 4 C2H5OH
TEOS: Tetraethyl orthosilicate. No concentration given.
To calculate the percent recovery of SiO2, we need to compare the amount of SiO2 obtained to the amount that could have been obtained if the reaction went to completion.
First, let's calculate the molar mass of SiO2. Silicon (Si) has a molar mass of 28.0855 g/mol, and oxygen (O) has a molar mass of 15.999 g/mol. Since SiO2 contains two oxygen atoms, the molar mass of SiO2 is:
Molar mass of SiO2 = (28.0855 g/mol) + 2*(15.999 g/mol) = 60.0845 g/mol
Next, let's convert the mass of SiO2 obtained to moles. We know that the obtained mass is 0.3275 grams. Therefore, the number of moles of SiO2 is:
Number of moles of SiO2 = mass / molar mass = 0.3275 g / 60.0845 g/mol
Now, let's calculate the theoretical yield of SiO2. The balanced chemical equation of the reaction is needed to determine the molar ratio between TEOS and SiO2.
Assuming the balanced equation is:
4 TEOS + 12 H2O -> 4 SiO2 + 12 Ethanol
The molar ratio between TEOS and SiO2 is 4:4, or 1:1.
Since we started with 3 mL of TEOS in H2O, we need to convert this volume to moles. The molar volume of a gas at standard temperature and pressure is 22.414 L/mol. However, since TEOS is a liquid, we need to consider its density and its molar mass.
Unfortunately, the density of TEOS and its molar mass are not provided. Without this information, we cannot accurately convert the volume to moles.
Hence, we cannot determine the percent recovery of SiO2 without knowing the molar mass and density of TEOS.