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Moles: part 2 body parts (mole ratio) math : the knee bone is connected to the thigh bone…. How many toes connected to the hands (assuming no deformities) ?. 5. 4. 3. 2. 1. x. 10 toes person. 5 hands . 1 person hand. = 50 toes. x.
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Moles: part 2body parts (mole ratio) math: the knee bone is connected to the thigh bone….
How many toes connected to the hands (assuming no deformities) ? 5 4 3 2 1 x 10 toes person 5 hands 1 person hand = 50 toes x
Solving Mole parts (ratio) problems: The overall flow goes so… • Convert any given weight or molecule count to moles (“all roads lead through moles”) • Relate the computed moles above to desired moles (put unknown on top, known on bottom of the ratio for simplicity) • If necessary, convert desired moles to target grams or molecule count
Simplest `body’ parts example : mole Mole Octane = C8H18 How many H are in 20 moles of octane ? 20 mols octane * 18 mol H = 360 mol H mol octane
Isohexane has the formula C6H14. How many C moles are present if we have 0.1667 moles of isohexane • 0.0277 mol C • 1.00 mol C • 36 mol C • 2.333 mol • None of the above
`body’ parts example 2 : Weight moles first, then mol Mol Octane = C8H18 How many moles of octane contain 24 grams of C (at. wt. = 12 g/mol) 1)Convert grams C to moles C 2) Relate moles C to moles octane 1 mol octane=x 8 mol C 2 24 g = 2 moles C 12 g/mol C x= 2/8=0.25 moles octane
Isohexane has the formula C6H14. How many moles of isohexane are formed with 24 grams of C • 0.333 moles isohexane • 2 moles isohexane • 0.1667 moles isohexane • 3 moles isohexane • Stoichiometry blows F. None of the above
`body’ parts example 3 : Weight moles , then mol Mol weight Octane = C8H18 (MW=114) How many grams of H are in 10 grams of Octane ? (1 mole H=1 g H) 2) Relate moles H to moles octane 1)Convert grams octane to moles octane 10 g = 0.0877 mol 114 g/mol octane 14 mol H= x 1 octane 0.0877 x= 14*0.0877=1.228 mol = 1.228 g
Isohexane has the formula C6H14. How many grams of H (at. Wt. = 1 g/mol) are combined in 300 grams of C6H14 (MW=86 g/mol) • 36.84 g H • 1.32 g H • 0.249 g H • 0.020 g H • 48.84 g H
“Practice, practice, practice….”
In-class exercise #3b: chem1114 MoleCalculations: part 2 3.1)mole to mole: how many moles of O are present in 0.1666 mole of C6 H12O6? 1 mol O 3.2) mole to mole how many moles of C6H12O6 can be made with 12 mole of O ? 2moles C6H12O6
In-class exercise #7b: chem 1114 Mole Calculations: part 2 3.3) weight to moles how many moles of C6H12O6 in a sample containing 216 g C ? 3mol 3.4)moles to weight how many grams of C6H12O6 are formed with 0.2666 mol H? = 4 g
3.5) moles to molecules how many molecules of O are present in 0.8333 mol of C6 H12O6? =5*1023 3.6) molecules to moles how many moles of C6 H12O6 are formed from 5.04*1025 atoms of H ? 7 moles
3.7 mass to molecules: how many moleculesof C6 H12O6form from 96 g of C ? 8 *1023 molecules ofC6H12O6 3.8 atoms to mass: how many grams of H are combined with 2.7*1024 atoms of O in C6H12O 6 ? 9 grams H