Explanation:
Step 1: Write out the chemical formula of the compound.
Magnesium Chloride = MgCl^2
Step 2: Convert moles into number of compounds using Avogadro's number
0.5 moles MgCl^2 ⋅(6.022⋅10^23 - 1 mole MgCl^2)= 3.011⋅ 10^23
Step 3: Determine how many Chloride ions there will be in 1 compound
There will be 2 Cl− ions in each compound (Cl^2 part)
Step 4: Multiply the number from Step 2 by the number in Step 3
3.011 ⋅ 10^23 ⋅ 2= 6.022 ⋅ 10^23
We do this because the ratio is 2 Cl− ions for every 1 compound.
In the case of finding how many ions in general (both sodium and chloride), we would multiply by 3 because there are 3 ions per 1 compound.
I hope this helped!
