Answer:
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.
