Question

How many barium ions does one mole of barium phosphate contain?

Answer 1

Answer : The number of barium ion is, $18.066\times 10^{23}$

Explanation :

The formula of barium phosphate is, $Ba_3(PO_4)_2$

Barium phosphate is formed from three barium ion and 2 phosphate ion by criss-cross method. That means,

1 mole of barium phosphate dissociates to give 3 moles of barium ion and 2 moles of phosphate ion.

Or,

As we know that, 1 mole contains $6.022\times 10^{23}$ number of ions.

1 mole of barium phosphate dissociates to give $3\times 6.022\times 10^{23}$ moles of barium ion and $2\times 6.022\times 10^{23}$ moles of phosphate ion.

The number of barium ion = $3\times 6.022\times 10^{23}=18.066\times 10^{23}$

The number of phosphate ion = $2\times 6.022\times 10^{23}=12.044\times 10^{23}$

Hence, the number of barium ion is, $18.066\times 10^{23}$

Answer 2

The molecular formula of barium phosphate is Ba3(PO4)2. This is because, barium (Ba) is has +2 charge and the phosphate group (PO4) has a -3 charge.

Therefore, 1 mole of Ba3(PO4)2 has 3 moles of Ba2+ and 2 moles of PO4(3-)

Now:

1 mole of Ba2+ has $6.023*10^{23}$Ba2+ ions

Therefore, 3 moles of Ba2+ would correspond to : 3*6.023*$10^{23} = 1.807*10^{24}$ Ba2+ ions