How many grams of water (H2O) have the same number of oxygen atoms as 7.0 mol of oxygen gas

7.0 mol of oxygen gas contain the same number of oxygen atoms as 250 g of water.

We want to know the mass of water (H₂O) that has the same number of oxygen atoms as 7.0 mol of oxygen gas (O₂).

First, we will calculate the number of oxygen atoms in 7.0 mol of O₂ considering the following relations.

Now, we want to calculate the mass of H₂O that contains 8.4 × 10²⁴ atoms of O. We will consider the following relations.

7.0 mol of oxygen gas contain the same number of oxygen atoms as 250 g of water.

Learn more about Avogadro's number here: link

126 g of water, H2O.

Explanation:

First, we'll begin by calculating the number of atoms in 7 mole oxygen gas.

This is illustrated below:

From Avogadro's hypothesis, we understood that 1 mole of any substance contains 6.02×10²³ atoms. This means that 1 mole of O2 also contains 6.02×10²³ atoms.

Now, if 1 mole of O2 contains 6.02×10²³ atoms, then 7 moles of O2 will contain = 7 × 6.02×10²³ = 4.214×10²⁴ atoms.

Finally, we shall determine the mass of H2O that will contain 4.214×10²⁴ atoms.

This is illustrated below:

6.02×10²³ atoms is present in 1 mole of any substance contains

1 mole of H2O = (2x1) + 16 = 18 g

6.02×10²³ atoms is present in 18 g of H2O.

Therefore, 4.214×10²⁴ atoms will be present in = (4.214×10²⁴ × 18)/6.02×10²³

= 126 g of water, H2O.

Therefore, 126 g of water, H2O will contain the same number of oxygen atoms as 7.0 mol of oxygen gas.