How many formula units are in a sample of NaCl that has a mass of 175 g?

Question

Quizplus · Accepted Answer

To solve this problem, we need to use the molar mass of NaCl to convert grams to formula units.

1) Find the molar mass of NaCl: 
Na = 22.99 g/mol 
Cl = 35.45 g/mol 
Molar mass of NaCl = 22.99 + 35.45 = 58.44 g/mol

2) Use the molar mass to convert grams to moles: 
175 g NaCl x (1 mol NaCl/58.44 g NaCl) = 2.995 mol NaCl

3) Use Avogadro's number (6.022 x 10^23) to convert moles to formula units: 
2.995 mol NaCl x (6.022 x 10^23 formula units/mol) = 1.80 x 10^24 formula units

Therefore, the answer is B: 1.80 x 10^24 formula units.

How Many Formula Units Are in a Sample of NaCl