In this assignment you will calculate the mass of 5 moles and 5 micro-moles of your element super hero. In just this one sentence there are two terms you may not be familiar with.
What is mass?
Mass is an intrinsic property of a physical body that determines its resistance to acceleration and its strength of gravitational attraction to other bodies. Some common units of mass are grams, kilograms, daltons, and moles.
What is a mole?
Since 2018 a mole has been defined as the number of atoms in 12 grams of carbon 12. When I was in high school, a mole was defined based on the number of atoms in 1 gram of hydrogen….not deuterium or tritium! So 12 grams of carbon 12 contains 6.02214076×1023 carbon particles.
- Why not use carbon 14 or H2 deuterium?
- Could you have one mole of electrons or one mole of elephants?
4Cu + O2 → 2 CuO (cuprous) or 2 Cu + O2 → 2 CuO (cupric)
Measuring amounts in grams is fine for baking. When you want the right product, counting heads in moles becomes necessary.
What does 6.02214076×1023 mean?
Some of you may have forgotten scientific notation. Scientific notation is a ways of expressing very large or very small numbers as a number between 1 and 10 multiplied by an exponent of 10. These are some examples to jog your memory
Now for the assignment
Do this for your element following our mole friend’s example. Our mole friend’s hero element is antimony. Antimony has an atomic mass of 121.76 Daltons, that is the same thing as grams per mole.
Our mole friend thought that 0.000609 g Sb was kind of an awkward expression. It decided to multiply this value by 1000 to get the same mass in milligrams. It could have added this conversion to the big fraction that scientists refer to as dimensional analysis.