The Mole, in all it’s glory…

Moles… or the chemist dozen, other known as 602000000000000000000. Just to sweeten up that number let’s just use 6.02×10^23. The number was created by Lorenzo Romano Amedeo Carlo Avogadro.. Let’s call him Avogadro, since he was the one to create a “mole” it’s also called Avogadro’s Number (creative right?) After our discussions in class and notes; I see a mole as a unit of measurement. *”A mole is what chemist use to measure the quantities at the magnitude of 602 sextillion”. Let’s say you have a glass of water that weighed to be 18.02 grams. You would have 6.02×10^23 molecules of water. What I have taken from this section is just how large a mole is and how we use it. What really shocked me you could say is just how large that number is, it’s inconceivable.

mole(a mole

 

 

 

)chemcat(this was painful to make)

How to – Percent Composition

Percent Composition is the how much an element is to that of the compound it’s in. When given a compound, let’s say  we want to know the percentage of Potassium in K2C2O7, which would be Potassium Dicarbonate. You would take the weight of the element from the Periodic Table and add them together. Potassium weights 39.09 amu, Carbon weights 12.01 amu, Oxygen weighs 16.00 amu. Now just add them up to get the sum of the compound. 2(39.0 amu)+2(12.01amu)+7(16.00amu)= 214.18 amu. Now divide the total amount of weight by the weight of Potassium (in the compound). 78.18/214.18= .365 or %36.5. Using percent composition in Chemistry can help us with the amount of a component in a compound.

Science by the Numbers

Accuracy and precision both have different meanings. When we talk about accuracy, we  refer it to how closely the data is with the true value, while precision is how close single measurements are together. It’s easy to visualize, imagine you’re shooting at a target; your goal is to aim at the “bulls-eye” or expected target. Being accurate is your ability to get your shots close to the center; when precision is having your targets group together in a close bunch, though they may not be near the bulls-eye. These ideas are important when we talk about numbers, more importantly, significant numbers. Significant numbers are a degree of accuracy, having exact and inexact numbers. Numbers that are know and certain are exact, while inexact are those who are unknown, for example, if I say a car is $9,000, then that number can be anywhere between under 10,000 and more than 8,000. Only 1 significant number was in 9,000; but if I use a more accurate number like $9,239 then it’s an more accurate than just 9,000 because more numbers are know and a greater amount of significant numbers. Even the atomic weight was changed because we found more accurate numbers that changed the weight of 19 elements.