amount of substance

1、what is the molewhat is the avogadro constantTeaching objectives relationship between mole and number of particlesrelationship between mole and massKeywordsamount of substance avogadro constantatommoleculeion number of molesmolar massgram 物质的量原子摩尔数离子摩尔质量分子阿伏加德罗常数克How many water molecules in a drop o

2、f water ? 1670000000000000000000= 1.671021What is the mole? The relative atomic mass or relative molecular mass of a substance in grams is called a mole of the substance We often refer to the mass of a mole of substance as its molar mass (abbreviation M) The units of molar mass are g mol-1 One mole

3、of a substance is the amount of that substance which has the same number of specific particles (atoms,molecules or ions) as there are atoms in exactly 12g of the carbon-12 isotope The abbreviation for a mole is mol 1 mol 1 molthe relative atomic (molecular) mass of a substance12g of the carbon-12 is

4、otopeavogadro constant = 6.02*1023atoms,molecules ,ions and electronswhat is the mole? 意大利化学家。生于一个律师家庭。意大利化学家。生于一个律师家庭。17921792年进都灵大学法律系学习，取得年进都灵大学法律系学习，取得法学博士学位。法学博士学位。18001800年弃法从理，年弃法从理，18201820年被选为都灵科学院院士年被选为都灵科学院院士。他。他在在化学上的重大贡献是建立化学上的重大贡献是建立分子学说分子学说。为了纪念阿伏加德罗的伟大功绩，将为了纪念阿伏加德罗的伟大功绩，将0.0120.012kg

5、kg1212C C中所含的中所含的C C原子数目称为原子数目称为阿伏加德罗常数。它是自然科学中的阿伏加德罗常数。它是自然科学中的基本基本常数之一。常数之一。The avogadro constant is given the symbol L L Johann Joseph LoschmidtJohann Joseph Loschmidt阿伏加德罗阿伏加德罗Avogadro 17761856 Do you know? a mole of sodium (Ar=23.0) weights , there are Nain 1 mole of sodium chloride (NaCl) ther

6、e are sodium ions and chloride ions 1 mole of chlorine23.0gLLLmoles and massnumber of moles (mol)= -mass of substance in grams (g)molar mass (g mol-1)number of moles (mol)= -the total numberavogadro constant (mol-1)Worked exampleHow many moles of sodium chloride are present in 117.0 g of sodium chloride, NaCl ? molar mass of NaCl =23.0+35.5 =58.5 g mol-1 number of moles = mass/molar mass =117.0/58.5 =2.0 molCheck-upuse these Ar values (Fe=55.8,N=14.0,O=16.0,S=32.1) to calculate the amount of substance in moles in each of the fo