how many molecules of O2 are in 5.0g of O2? how many atoms of oxygen are in this many molecules?
moles= 5.0g/32
atoms= 2*moles*avagradro's number
To calculate the number of molecules of O2 in 5.0g of O2, we'll follow these steps:
Step 1: Determine the molar mass of O2.
The molar mass of O2 (oxygen gas) is 32.00 grams/mol. This is because oxygen has an atomic mass of 16.00 grams/mol, and O2 consists of two oxygen atoms.
Step 2: Convert grams to moles.
We'll use the formula:
moles = mass / molar mass
moles = 5.0g / 32.00 grams/mol
moles ≈ 0.15625 mol
Step 3: Calculate the number of molecules.
One mole of any substance contains 6.022 x 10^23 particles (Avogadro's number).
number of molecules = moles × Avogadro's number
number of molecules ≈ 0.15625 mol × 6.022 x 10^23 molecules/mol
number of molecules ≈ 9.4 x 10^22 molecules of O2
Thus, there are approximately 9.4 x 10^22 molecules of O2 in 5.0 grams of O2.
To find the number of atoms of oxygen in this many molecules, we should consider that each molecule of O2 contains two atoms of oxygen.
number of atoms of oxygen = number of molecules × 2
number of atoms of oxygen ≈ 9.4 x 10^22 molecules × 2 atoms/molecule
number of atoms of oxygen ≈ 1.88 x 10^23 atoms
Therefore, there are approximately 1.88 x 10^23 atoms of oxygen in this many molecules of O2.
To find the number of molecules of O2 in 5.0g of O2, you need to use the concept of moles, the molar mass of O2, and Avogadro's number. Here's how you can calculate it step by step:
1. Find the molar mass of O2, which is the sum of the atomic masses of two oxygen atoms:
O2 = (2 * atomic mass of oxygen)
The atomic mass of oxygen (O) is approximately 16.00 g/mol.
Therefore, the molar mass of O2 = 2 * 16.00 g/mol = 32.00 g/mol.
2. Convert the given mass of O2 (5.0g) to moles using the molar mass of O2:
Moles of O2 = (mass of O2 / molar mass of O2)
Moles of O2 = 5.0g / 32.00 g/mol
Moles of O2 ≈ 0.15625 mol (rounded to five decimal places)
3. Use Avogadro's number to convert moles to the number of molecules:
Number of molecules of O2 = (moles of O2 * Avogadro's number)
Avogadro's number is approximately 6.022 × 10^23 molecules/mol.
Number of molecules of O2 = 0.15625 mol * 6.022 × 10^23 molecules/mol
Number of molecules of O2 ≈ 9.4090625 × 10^22 molecules (rounded to significant figures)
Now, let's calculate the number of atoms of oxygen in this many molecules.
Since there are two oxygen atoms in each O2 molecule, multiply the number of molecules of O2 by 2 to get the number of oxygen atoms:
Number of oxygen atoms = (Number of molecules of O2 * 2)
Number of oxygen atoms = 9.4090625 × 10^22 molecules * 2
Number of oxygen atoms ≈ 1.8818125 × 10^23 atoms (rounded to significant figures)
Therefore, there are approximately 9.4 × 10^22 molecules of O2 and 1.9 × 10^23 atoms of oxygen in 5.0g of O2.