I really don't understand why counting units (such as the mole) are use so much more often in chemistry instead of a mass unit. Can anybody explain this to me?
2006-09-14 08:20:07 · 3 answers · asked by Anonymous in Education & Reference ➔ Homework Help
Because a mole accurately describes a fixed number of atoms - mass does not.
For example, for H20, it's not 2 grams of Hydrogen to 1 gram of Oxygen - it's 2 atoms of hydrogen and 1 atom of Oxygen. Oxygen's atomic number is 8, so if you had 10g of water, 8g is Oxygen, and 2g is Hydrogen.
Using moles in Chemistry allows you to accurately describe how the chemical reactions are taking place.
2006-09-14 08:24:43 · answer #1 · answered by ³√carthagebrujah 6 · 1⤊ 0⤋
Would you use the number of grains of rice to measure cooking instructions for rice? Could get problematic.
consider combustion
CH4 + 2(O2) ---> 2(H2O) + CO2
can you see how the just doing moles would be easier than adding up all the AMUs and then mulitplying them. Especialy when you consider the reactants and products will have diferent concentrations of the individual elements.
2006-09-14 15:38:37 · answer #2 · answered by joe b 2 · 0⤊ 0⤋
mass can vary and mole is fixed
2006-09-14 15:35:16 · answer #3 · answered by raj 7 · 0⤊ 0⤋