Question

How many NaCl formula units does 0.16 mg of salt contain?

Answer 1

Explanation:

First, find the number of moles of sodium chloride in the 0.12 mg by using the formula moles = mass/molar mass. But, 1 mol contains an Avagadro number of particles, ie 6.022×1023 particles. Therefore by ratio and proportion, 2.051⋅10−6 mol will contain 1.2×1018 particles of NaCl .