How many moles of na2cr2o7 contain 14 moles of oxygen atoms?

The number of moles of the compound are 2 moles.

Explanation:

We are given:

Moles of oxygen atom = 14 moles

The chemical formula for the given compound is

In 1 mole of sodium dichromate, 2 moles of sodium atoms, 2 moles of chromium atoms and 7 moles of oxygen atoms are present.

To calculate the moles of compound, we use unitary method:

7 moles of oxygen atoms are present in 1 mole of sodium dichromate.

So, 14 moles of oxygen atoms will be present in of sodium dichromate.

Hence, the number of moles of the compound are 2 moles.