How many ions are in 13.54 mol sample of nacl?
and can you tell me how you got this answer?

You don't have to do this first part, but I think it's important to know if something is ionic, sometimes you get trick questions on exams. 

Na has an electronegativity of 0.93.
Cl has an electronegativity of  3.16. 
                                               ---------   There is a difference of,       2.23     

When the electronegativity difference is greater than 1.5, the compound is ionic. 

NaCl is an ionic compound, so when it dissolves in a solvent, it separates into two. 
Steps to solve:
1. There are 6.02 x 10²³ molecules in one mole
2. There are 13.54 moles in our sample
3. We must convert moles to molecules by multiplying. 
4. After the number of molecules is obtained, you must multiply that number by 2 to obtain the number of ions, because NaCl is ionic. 

Hope this helps!