Calculations with Moles

by  by  by No. of Grams x by No. of x by Moles x by No. of No. of formula mass (g/mol) x by x by No. of Moles x by 6.02 x 1023 22.4 L/mol  by  by No. of Particles No. of Liters

3 types calculations mole-mass (grams) mole-volume (liters) mole-number of particles (avogadro’s #)

Moles to Mass (and back) for mass-mole conversions: you must calculate the FM first

Mole/Mass Conversions What is the mass of 3 moles of sugar? formula for sugar: C6H12O6 step 1: see what mole-map says! remember, mass is in grams! moles x formula mass = grams

Conversions 180g/mole C6H12O6 step 2: find the formula mass of C6H12O6 6(12g) + 12(1g) + 6(16gl) = 180 g this means: 180g/mole C6H12O6

( ) Conversions step 3: 180g/mole C6H12O6 x 3 moles (3 moles) 180 g = 540 g mole ( )

Mole-mass conversions How many moles C6H12O6 are in 270.0 grams C6H12O6? step 1: look at mole map! grams divided by formula mass = moles step 2: formula mass of C6H12O6 = 180 g/mol

Mole-mass conversions How many moles C6H12O6 are in 270.0 grams C6H12O6? step 3: 270.0 g = 1.5 moles 180 g/mol

Mole – Volume conversions

Mole-Volume Conversions for any gas: 1 mole = 22.4 liters at STP STP = standard temperature (0C) and pressure (1 atm) (see Table A)

Mole-Volume Conversions What is volume occupied by 4 moles H2(g) at STP? step 1: Look at mole map! volume = # moles x 22.4 L/mole

Mole-Volume Conversions step 2: calculate! 4 moles x 22.4 L = 89.6 Liters mole

Mole-Volume Conversions How many moles of N2 are in 33.6 L? mole map: take liters and divide by 22.4 L/mole

Mole-Volume Conversions step 2: calculate: 33.6 Liters__ = 1.5 moles 22.4 L/mole