Two-step mole conversions

When converting perticles into grams or grams into particles, use two-step mole conversion.

Converting PARTICLES into GRAMS
Ex. What is the mass of 7.32ｘ10¹⁵ Tin(Sn)　atoms?
      1.Convert ATOMS into MOLES

          7.32ｘ10¹⁵Sn atoms ｘ 1mole / 6.022ｘ10²³ atoms
                        = 1.21ｘ10⁻⁸Sn moles
                          (always remember SIG FIGS!)

      2. Then, convert MOLES into GRAMS

         According to the periodic table, 1 mole of Sn = 118.7g
         1.21ｘ10⁻⁸Sn moles ｘ 118.7g / 1mole
                         = 143.627 g of Sn

     So, the mass of 7.32ｘ10¹⁵ Tin atoms is 144 grams.


Converting GRAMS into PARTICLES
Ex. How many atoms of Hydrogen are present in 23.0g of NH₃?

1. Convert GRAMS into MOLES

          Since 1mole of NH₃=  17.0g,
          23.0g of NH₃ ｘ 1mole / 17.0g
                       = 1.35 moles of NH₃

     2. Then, convert MOLES into PARTICLES

　　　　 1.35 moles of NH₃ｘ 6.022ｘ10²³ molecules/ 1mole
                       = 8.13ｘ10²³ molecules of NH₃
           8.13ｘ10²³ molecules of NH₃ｘ  3H atoms / 1 molecule NH₃
                       = 2.44ｘ10²⁴H atoms

     So, 2.44ｘ10²⁴atoms of Hydrogen are present in 23.0g of NH₃.

Here are some mole jokes that you might enjoy~!

Why are moles bad at counting?

Because they only know one number.
What's the mole's favorite brand of soda?
Coca-Mola.

Why are moles always on the phone?
Because they love moleble devices.
Why do moles love Tyra Banks?
Because she's on America's Next Top MoledelWho is the the mole's favorite actor?
Mole Gibson

What does Avogadro put in his hot chocolate?
Marsh-mole-ows!