Question

Amount of oxygen in 2.5 moles of water is *

Answer 1

Explanation:

From a balanced chemical equation we know that

2H2O ↔ 2H2 + O2

Thus, we see that two mole of water contains one mole pf oxygen

So, for 2.5 moles of water, we will have 1.25 moles of oxygen.

We know,

moles = mass/ molar mass

So, mass of oxygen = moles * molar mass

Mass of oxygen = 16 * 1.25 = 20 g

Answer 2

The amount of oxygen in 2.5 moles of water is 40  grams.

Explanation:

The molecular formula of water is H₂O.

1 mole of water contains 1 mole of oxygen.

Moles of oxygen = (Weight of oxygen)/(Molecular weight of oxygen)

Now,

Moles of oxygen × Molecular weight of oxygen = Weight of oxygen

Where,

Moles of oxygen = 2.5 moles (Given)

Molecular weight of oxygen = 16 g (constant)

On substituting the values, we get,

2.5 × 16 = Weight of oxygen

∴ Weight of oxygen = 40  g