Question

M(Si)=15г н.у.=22.4л\моль V(O2-?​

Answer 1

Si+O2=SiO2

n(Si)=15/28=0.54моль

V=0.54*22.4=12.096л

Answer 2

To calculate the volume of oxygen gas (O2) at standard conditions (0°C and 1 atm) based on the given information, we'll use the concept of stoichiometry and molar volumes.

Given information:

1. Molar mass of Si (silicon) = 15 g/mol
2. Avogadro's number = 6.022 x 10^23 molecules/mol (1 mole contains 6.022 x 10^23 molecules)
3. Volume of 1 mole of gas at standard conditions (STP) = 22.4 L/mol

The first step is to determine the number of moles of silicon (Si) in 15 grams of it. To do that, we'll use the formula:

Number of moles = Mass of substance (in grams) / Molar mass

Number of moles of Si = 15 g / 28.0855 g/mol ≈ 0.534 moles

Now, we need to find the number of moles of oxygen ions (O2-) required to react with 0.534 moles of Si in a balanced chemical equation.

The balanced chemical equation for the reaction between silicon and oxygen is:

3 Si + 2 O2 → Si3O4

According to the equation, 3 moles of silicon react with 2 moles of O2. So, to find the moles of O2 required, we'll use the ratio:

Moles of O2 = (2 moles O2 / 3 moles Si) * 0.534 moles Si ≈ 0.356 moles O2

Finally, we can calculate the volume of O2 at STP using the molar volume:

Volume of O2 = Moles of O2 * Molar volume at STP Volume of O2 = 0.356 moles O2 * 22.4 L/mol ≈ 7.98 L

So, the volume of oxygen gas (O2) at standard conditions (0°C and 1 atm) is approximately 7.98 liters.