Chemistry 20 Mole Conversions

What is a Mole? A term of measurement A counting number – Similar to saying 1 dozen = 12 things Avogadro's Number (N A ) 6.02 x items A VERY LARGE NUMBER!!! = 1 mole

3.00 moles of little green peas would cover 250 planets the size of Earth 1m deep in green peas 1.00 mole of basketballs would fill a bag the size of the Earth

Mole Conversions Mass In Grams Moles Molar Mass g/mol

Molar Mass Molar mass is the mass of one mole in an element or compound Atomic mass tells us that the units are grams per mole g/mol Examples: Carbon, C = g/mol Phosphorus, P = g/mol

Molar Mass Examples What is the Molar Mass of: Salt, NaCl: Na = 22.99g/molCl = 35.45g/mol NaCl = 22.99g/mol g/mol = 58.44g/mol Glucose, C 6 H 12 O 6 : C 6 = 6(12.01 g/mol )H 12 = 12(1.01 g/mol ) O 6 = 6( 16.00g/mol) C 6 H 12 O 6 = 6(12.01g/mol) +12(1.01g/mol) 6(16.00g/mol) = g/mol

Sodium bicarbonate, NaHCO 3 : Na= 22.99g/mol H=1.01g/molC=12.01g/mol O = 3(16.00g/mol) NaHCO 3 = 22.99g/mol g/mol g/mol + 3(16.00g/mol) = 84.01g/mol

Mole Conversion Examples A grade eleven chemistry student has 3.00 g of boron tribromide (BBr 3 ). How many moles of BBr 3 is this? Molar mass of BBr 3 = (79.90) = g/mol 3.00g BBr 3 x 1mole= mole BBr g REMEMBER SIG FIGS!

If I have 50.0g of calcium chlorate (CaClO 3 ) 2 how many moles do I have? Molar Mass (CaClO 3 ) 2 = 2(40.08) + 2(35.45) + 6(16.00) = g/mol 50.0g (CaClO 3 ) 2 x 1 mole = mole (CaClO 3 ) g Sig Figs

Determine the mass of the following amount: 6.94 mol barium chloride (BaCl 2 ) Molar Mass BaCl 2 = (35.45) = g/mol 6.94 mol BaCl 2 x g = 1.45 x 10 3 g BaCl 2 1 mole Remember only 3 sig figs

Chemistry 20 Mole Conversions

Mole Conversions Respective Particles Moles Avogadro’s Number 6.02 x molecules or atoms or formula units

Mole Conversion Examples If a chemist is experimenting with atoms of lead how many moles is she dealing with? Avogadro’s number = 6.02 x atoms atoms Pb x 1 mole= 9.5 x mol 6.02 x atoms 2 sig figs

How many moles is in 2.97 x atoms of Vanadium? 2.97 x atoms of V x 1 mole 6.02 x atoms = 49.3 moles of V

Determine the number of molecules in the following: a)1.01 moles of bismuth 1.01 mol Bi x 6.02 x atoms 1 mole = 6.08 x atoms of Bi

b) 2.5 moles of manganese 2.5 mol Mn x 6.02 x atoms 1 mole = 1.5 x atoms of Mn

If the students in a chemistry 20 class have 7.66 x molecules of hydrogen peroxide, H 2 O 2, how many moles do they have? 7.66 x molecules x1 mole 6.02 x molecules = 1.27 x molecules of H 2 O 2

Chemistry 20 Mole Conversions

Mole Conversions Volume Moles Litres of Gas at STP 22.4 L

Mole Conversion Examples Determine the volume, in liters, occupied by moles of helium gas at STP moles He (g) x 22.4L = 0.67 L of He (g) 1 mole REMEMBER UNITS

What is the volume of 0.05 mol of neon gas at STP? 0.05 mol Ne x 22.4L= 1.12L of Ne (g) 1 mole

How many moles of argon atoms are present in 11.2 L of argon gas at STP? 11.2L Ar (g) x 1 mole = 0.5 mole Ar (g) 22.4L

What is the volume of 1.2 moles of water vapor at STP? 1.2 mol H 2 O (g) x 22.4L= 26.88L of H 2 O 1 mole

Chemistry 20 Mole Conversions

Mole Conversions Representative Particles Volume at STP MOLE Mass x 1 mole 22.4L X 22.4L 1 mole x molar mass 1mole x 1mole molar mass x 1 mole 6.02 x particles x 6.02 x particles 1 mole

Mixed Mole Conversion 1.Write down the question’s the given and the unknown. 2.Convert the given unit to number of moles. 3.Convert the number of moles found to the unknown unit. 4.Make sure the answer has the correct unit and number of sig figs.

Mole Conversion Examples Calculate the mass, in grams (g), of the following: a)3.00L of O 2(g) 3.00L of O 2(g) x 1 mole x g = 4.29 g O 2(g) 22.4L 1mole b) 15 atoms of gold 15 atoms Au (s) x 1 mole x g = 4.9 x g Au 6.02 x atoms 1 mole

Calculate the number of atoms in 2.0L of SO 3 gas. 2.0 L SO 3(g ) x 1 mole x 6.02 x atoms = 5.3 x atoms SO L 1 mole

If the students in a Chemistry 20 class have 3.25 x 10 5 molecules of CO 2(g), how many litres do they have? 3.25 x 10 5 molecules of CO 2(g) x 1 mole = 5.40 x mole 6.02 x molecules 5.40 x mole CO 2 x 22.4L = 1.21 x L CO 2 1 mole