Molar Conversions

Moles The standard unit of measure for the amount of a substance in numbers

Dozen = 12 of anything

Moles = the amount of a substance that would = its mass in g from the PT

Moles = x of anything

Molar Conversions Mass to moles Volume of a gas to moles Particles to moles Volume of a solution to moles

Converting to Moles

From Mass Use atomic masses from the periodic table NaCl = 58.5 g/mole * x amu = 1 g

From Gas Volume At STP multiply volume by (1 mole/22.4 L) At non-STP use PV = nRT

Particles to Moles Multiply # particles by this conversion factor: 1 mole atoms OR molecules 6.02 x atoms OR molecules * pay attention to the question!

From Sol’n Volume Multiply molarity (M) by volume (in L) n = M x V * M = moles/L

Convert 7.0 g of silicon to moles of Si

7.0 g Si 1 mole Si = 2.5 x mol Si g Si

Convert 250 g of CaCO 3 to: moles of CaCO 3 how many moles of O?

250 g CaCO 3 1 mol CaCO 3 = 2.5 mol CaCO g CaCO 3 1 mol CaCO3 3 mol O = 7.5 mol O g CaCO 3 1 mol CaCO 3

Convert 3.0 moles of helium to grams of He

3.0 mol He g He = 12 g He 1 mol He

Convert 5.6 L of oxygen gas at STP to moles Oxygen atoms

5.6 L O 2 1 mole O 2 2 mol O = 0.50 mol O 22.4 L1 mol O 2

Convert moles of helium to volume at STP

0.500 mol He 22.4 L He = 11.2 L He 1 mol He

Convert: 2.0 x atoms He to moles

2.0 x atoms He 1 mol He = 3.3 mol He 6.02 x atoms He

Convert 3.0 moles of glucose to molecules

3.0 mol C 6 H 12 O x 1023 molecules C 6 H 12 O 6 = 1.8 x molecules C 6 H 12 O 6 1 mol C 6 H 12 O 6

Convert 250 mL of 0.10 M HCl to moles

0.10 M HCL = 0.10 mol HCL 250 mL 1 L 0.10 mol HCL = 2.5 x mol HCL 10 3 mL 1 L H 2 O 1 L

Determine the volume required to make 60.0 g NaOH into a 0.75 M solution

60 g NaOH 1 mol NaOH = mol NaOH mol NaOH = 0.75 M NaOH X = 2 L H 2 O g NaOH X L H 2 O

Convert 6.8 g NH 3 to volume at STP

6.8 g NH 3 1 mole NH L NH 3 = 8.9 L NH g NH 3 1 mole NH 3

Convert 3.0 x molecules of CO 2 to mass in kg

3.0 x molecules CO 2 1 mol CO g CO 2 1kg = 2.2 kg x molecules CO 2 1 mole CO g

Calculate the number of oxygen atoms in 32  g of Fe 2 O 3

Calculate the number of atoms in 16 ng of Fe 2 (SO 4 ) 3

Calculate the mass of solute required to make 40.0 mL of 0.25 M Pb(NO 3 ) 2