Transcript Molar mass
Catalyst 1. How many particles are in one mole? 2. How many hours are there in 362 minutes 3. How many minutes are in 2 years? (1 year = 365 days; 1 day=24 h; 1 h=60 min) End Puppies! • You have 5 white dogs that weigh 15 pounds, 3 brown dogs that weigh 10 pounds, and 1 black dog that weighs 20 pounds. How much do all the dogs weigh together? Rate Yourself! Using your exit ticket score, rate yourself 1 – 4 on LT Lecture 3.3 – Molar Mass and Gram to Moles Conversion Today’s Learning Targets • LT 3.7 – I can calculate the molar mass of given element or compound. • LT 3.8 – Given an element, I can convert between the number of moles to grams and grams back to moles What is molar mass? I. Molar Mass • Molar mass is the mass, in grams, of 1 mole of substance. • The molar mass is equal to the mass listed on the periodic table • Units of Molar mass are g/mol Molar Mass How do we calculate molar mass? More Tables! Element Number of Molar Mass Total Total Molar Atoms in Element Mass Compound Molar Mass x = x = x = Class Examples • Ca • Br2 • Ca3(PO4)2 Table Talk • Calculate the molar mass for the following compounds: –KCN –Ca(NO3)2 –Al2(SO4)3 How do we convert between moles and grams? Our Focus for Today Grams of Substance A How do we go from grams to moles? Moles A Grams of A I. Converting from Grams to Moles & Back • It is possible to easily convert between grams and moles of a substance. • We accomplish this conversion using the same tools of dimensional analysis we talked about last week. II. OUR CONVERSION FACTOR FOR GOING BETWEEN GRAMS AND MOLES… III. Using the Conversion Factor When converting from grams to moles you must DIVIDE by the molar mass Grams Grams Moles Moles When converting from moles to grams you must MULTIPLY by the molar mass Grams Moles Grams Moles Class Example • If you react 360 g of C6H12O6 how many moles of C6H12O6 did you react in this reaction? Table Talk • If you start with 36 g of H2O, then how many moles of H2O do you react? Class Example • If we place 15 moles of NaN3 how many grams of NaN3 do you have before the reaction? Let’s Go Big Time! • If we place 26 moles of MgCl2 how many grams of MgCl2 do you have before the reaction? BINGO • Take out a sheet of paper and make a 4 x 4 grid by folding the paper in half 4 times. • Write the following terms/numbers on the sheet: 74 98 g/mol 75 122 Molar Mass g 56 37 Atomic Mass mol 97 36 99 55 123 Questions 1. The mass, in grams, of 1 mole of substance 2. This is the molar mass for an element on the Periodic Table 3. This is the units for molar mass 4. Calculate the molar mass for H2SO4 5. Calculate the molar mass for Ca(OH)2 6. Calculate the molar mass for AlPO4 7. Calculate the molar mass for HCl 8. Calculate the molar mass for MgO2 Moles of Chalk Collaborative Assignment • Some people might ask: “What do moles have to do with me?” This lab shows you!