Now, what is a mole? It is not a little mark on your cheek. It is not a burrowing animal. Actually, it is both of those things, but, in a chemistry context, a mole is just saying you have this much of something. The word mole was first used by the German chemist Wilhelm Ostwald at the end of the 19th century, and he came up with the word because of its relation to molecule.
Now, what does that mean? Well, think about the word dozen. If I say I've got a dozen of eggs, how many eggs do I have? Well, if I have a dozen of eggs, that means I have 12 eggs. So, if I say I have a mole of lithium atoms, how many lithium atoms do I have? That means that I have 6. Exact same idea, it's just that Avogadro's number is much hairier of a number than a dozen. So, let's use our new found powers of the mole and Avogadro's number to start doing some useful things.
Let's say that someone were to walk up to you and say, hey, you, I have a How many atoms of germanium am I dealing with? Pause this video and try to think about that.
So, let me clear out some space the periodic table of elements was taking up. All right, so we started off with The first step might be hey, let's convert this to grams of germanium.
And so, we can do a little bit of dimensional analysis. Privacy Policy. Skip to main content. Mass Relationships and Chemical Equations. Search for:.
Key Takeaways Key Points The mole allows scientists to calculate the number of elementary entities usually atoms or molecules in a certain mass of a given substance. This can also be written as 6.
Key Terms mole : The amount of substance of a system that contains as many elementary entities as there are atoms in 12 g of carbon Molar Mass of Compounds The molar mass of a particular substance is the mass of one mole of that substance.
Learning Objectives Calculate the molar mass of an element or compound. Key Takeaways Key Points The molar mass is the mass of a given chemical element or chemical compound g divided by the amount of substance mol. Molar mass serves as a bridge between the mass of a material and the number of moles since it is not possible to measure the number of moles directly.
Key Terms molar mass : The mass of a given substance chemical element or chemical compound in g divided by its amount of substance mol. Learning Objectives Convert between the mass and the number of moles, and the number of atoms, in a given sample of compound.
To convert between mass and number of moles, you can use the molar mass of the substance. The solution is the concept of the mole, which is very important in quantitative chemistry.
Amadeo Avogadro first proposed that the volume of a gas at a given pressure and temperature is proportional to the number of atoms or molecules, regardless of the type of gas. Although he did not determine the exact proportion, he is credited for the idea. It is equal to 6. A dozen molecules is 12 molecules. A gross of molecules is molecules. How do you convert grams to mole?
Question e5. Question 8d48c. Why is the mole an important unit to chemists? What's the mole number? How does the mole relate to carbon 12? How does the mole relate to molecules and ions? How do you calculate the moles of a substance?
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