Question

1. convert 8.43 x 1025 atoms of Fe to moles
2. convert 4.75 x 1024 molecules CO to moles
3. convert 2.43 x 1020 atoms Al to moles

Answer 1

Answer:

The number of moles of Fe are, 139.9 moles.

The number of moles of CO are, 7.89 moles.

The number of moles of Al are, $4.04\times 10^{-4}$ moles.

Explanation :

As we know that 1 mole of substance contains $6.022\times 10^{23}$ atoms or molecules.

Part 1:

As, $6.022\times 10^{23}$ atoms of Fe present in 1 mole

So, $8.43\times 10^{25}$ atoms of Fe present in $\frac{8.43\times 10^{25}}{6.022\times 10^{23}}\times 1=139.9$ mole

Thus, the number of moles of Fe are, 139.9 moles.

Part 2:

As, $6.022\times 10^{23}$ molecules of CO present in 1 mole

So, $4.75\times 10^{24}$ molecules of CO present in $\frac{4.75\times 10^{24}}{6.022\times 10^{23}}\times 1=7.89$ mole

Thus, the number of moles of CO are, 7.89 moles.

Part 3:

As, $6.022\times 10^{23}$ atoms of Al present in 1 mole

So, $2.43\times 10^{20}$ atoms of Al present in $\frac{2.43\times 10^{20}}{6.022\times 10^{23}}\times 1=4.04\times 10^{-4}$ mole

Thus, the number of moles of Al are, $4.04\times 10^{-4}$ moles.