Mole Conversions Part 2

Last class, we learned how to convert between particles to mass (grams); and conversions between mass (grams) to particles.

1) Particles→ Grams

• To find the mass of the molecule, another step is added to the equation from last time.   
• Ex: You want: 7.49x 10^21 atoms of Colbalt into grams,            

                          = 7.49x 10^21 atoms x 1 mole       x       58.9g = 0.733 of Cobalt.
                                                               ‒‒‒‒‒‒              ‒‒‒‒‒
                                                  6.022 x 10^23                1 mole
                           * the grams is the atomic mass of Cobalt


2) Grams → Particles    

• From the example above, the placement of 6.022 x 10^23 and the grams are swapped when converting grams→particles.
• Ex: You want the number of particles in 6.24 grams of Phosphorous.

                      = 6.24g x 1 mole x 6.022 x 10^23 = 1.21 x 10^23 atoms of Phosphorous
                                      ‒‒‒‒‒     ‒‒‒‒‒‒‒‒‒‒‒
                                      31.0g           1 mole

     * Please remember that significant figures always applys to the answers!

Here is a Mole Map to understand this concept visually!



For more expamples and practice visit this website!

http://www.fordhamprep.org/gcurran/sho/sho/lessons/lesson92.htm

Victoria