Question

How many moles of o are in 12.4 mol fe(no3)3?

Answer 1

The answer is 111.6 moles


In 1 mol Fe(NO3)3 there are 9 moles of oxygen

so in 12.4 mol of Fe(NO3)3 there will be 12.4 × 9 =

111.6 mols of oxygen.

Hope it helps!

Answer 2

111.6 moles of Oxygen are present in 12.4 moles of $\bold{\mathrm{Fe}\left(\mathrm{NO}_{3}\right)_{3}}$

Solution:

A mole of substance is known as mass of substance which contains same amount of fundamental units of atoms in 12.000 g of $^{12} C$ .Mole is the basic unit of substance.

In a mole of $\mathrm{Fe}\left(\mathrm{NO}_{3}\right)_{3}$ there are 9 mole of oxygen present.

So using basic unitary method no of moles of oxygen present in 12.4 moles of $\mathrm{Fe}\left(\mathrm{NO}_{3}\right)_{3}$ are,

$\bold{12.4 \times 9=111.6}$ moles of oxygen