Question #70c66

1 Answer
Oct 6, 2017

0.00021749

Explanation:

Whenever I need to find the number of moles of a substance, I always use the triangle:

enter image source here
Source, www.imgarcade.com, 2017

Through this triangle we can find:

  • Mass (no. of moles x molar mass of substance)
  • Molar Mass (mass (g) ÷ no. of moles)
  • Moles (mass (g) ÷ molar mass of substance)

NOTE: Before finding the number of moles in 5mg of Sodium, we must convert 5 milligrams to grams.

  1. 5mg = 0.005g

  2. #mol_(Na)# = #0.005/22.99#

                      =  0.00021749mol