<u>Answer:</u>
<u>For a:</u> The number of sodium ions in given amount of sodium sulfite are ![2.65\times 10^{22}](https://tex.z-dn.net/?f=2.65%5Ctimes%2010%5E%7B22%7D)
<u>For b:</u> The number of sulfite ions in given amount of sodium sulfite are ![1.325\times 10^{22}](https://tex.z-dn.net/?f=1.325%5Ctimes%2010%5E%7B22%7D)
<u>For c:</u> The mass of one formula unit of sodium ions is
grams
<u>Explanation:</u>
The chemical formula of sodium sulfite is
. It is formed by the combination of 2 sodium
ions and 1 sulfite
ions
To calculate the number of moles, we use the equation:
![\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}](https://tex.z-dn.net/?f=%5Ctext%7BNumber%20of%20moles%7D%3D%5Cfrac%7B%5Ctext%7BGiven%20mass%7D%7D%7B%5Ctext%7BMolar%20mass%7D%7D)
Given mass of sodium sulfite = 2.80 g
Molar mass of sodium sulfite = 126 g/mol
Putting values in above equation, we get:
![\text{Moles of sodium sulfite}=\frac{2.80g}{126g/mol}=0.022mol](https://tex.z-dn.net/?f=%5Ctext%7BMoles%20of%20sodium%20sulfite%7D%3D%5Cfrac%7B2.80g%7D%7B126g%2Fmol%7D%3D0.022mol)
Moles of sodium ions in sodium sulfite = (2 × 0.022) moles
According to mole concept:
1 mole of a compound contains
number of particles
So, 0.022 moles of sodium sulfite will contain =
number of sodium ions
Hence, the number of sodium ions in given amount of sodium sulfite are ![2.65\times 10^{22}](https://tex.z-dn.net/?f=2.65%5Ctimes%2010%5E%7B22%7D)
Moles of sulfite ions in sodium sulfite = (1 × 0.022) moles
According to mole concept:
1 mole of a compound contains
number of particles
So, 0.022 moles of sodium sulfite will contain =
number of sulfite ions
Hence, the number of sulfite ions in given amount of sodium sulfite are ![1.325\times 10^{22}](https://tex.z-dn.net/?f=1.325%5Ctimes%2010%5E%7B22%7D)
Molar mass of sodium sulfite = 126 g/mol
According to mole concept:
number of formula units are present in 1 mole of a compound
Or,
number of formula units of sodium sulfite have a mass of 126 grams
So, 1 formula unit of sodium sulfite will have a mass of = ![\frac{126}{6.022\times 10^{23}}\times 1=2.09\times 10^{-22}g](https://tex.z-dn.net/?f=%5Cfrac%7B126%7D%7B6.022%5Ctimes%2010%5E%7B23%7D%7D%5Ctimes%201%3D2.09%5Ctimes%2010%5E%7B-22%7Dg)
Hence, the mass of one formula unit of sodium ions is
grams