Stoichiometry

Moles and Molar mass

How Big is a Mole?

One mole of marbles would cover the entire Earth (oceans included) for a depth of two miles.

One mole of $1 bills stacked one on top of another would reach from the Sun to Pluto and back 7.5 million times.

It would take light 9500 years to travel from the bottom to the top of a stack of 1 mole of $1 bills.

Amedeo Avogadro

1 mole = 602213673600000000000000

or 6.022 x 1023

thousandsmillionsbillionstrillions

quadrillions?

Welcome to Mole Island

1 mole = 22.4 L @ STP

1 mol = molar mass

1 mol = 6.02 x 1023 particles

Stoichiometry Island Diagram

Mass

Particles

Volume Mole Mole

Mass

Known UnknownSubstance A Substance B

Stoichiometry Island Diagram

Volume

Particles

M

V

P

Mass Mountain

Liter Lagoon

Particle Place

Mole Island

Mass, Volume, Mole Relationship

Formation of Ammonia

Example: What is the number of moles of 14 g Li? (Li:7)

Example: What is the mass of 0.1 mole Ca? (Ca:40)

Example: Calculate the mole number of each of the followings.a) 13.7g Ba (Ba:137) b) 10.4 g Cr (Cr:52)

c) 635 g Cu (Cu:63.5) d) 12 g Mg (Mg:24)

Example: Calculate the mass of each of the following.a) 0.1 mole Na (Na:23) b) 0.5 mole Be (Be:9)

c) 2 mole K (K:39) d) 1.5 mole Fe (Fe:56)

Molecular weightExample 1: Calculate the molar mass of each of the following.

a) H2O b) P4

c) CaCl2 d) Na2CO3 e) C2H5OH f) Al(OH)3 g) NH4NO3h) H2SO4 i)Ca(OH)2 j) KClO4 k) H3PO4l) N2O5

m) CaCO3 n) Ca3(PO4)2

Example2: How many moles are 8.8 g of CO2 gas? Example 3: How many grams are 0.015 moles of Cl2 gas?

Example 4: How many moles are there in 10.26 g of Al2(SO4)3?

1)Calculate the molar mass of

Carbon dioxide

2) How many moles are there in 62.5 grams of NaHCO3

3) Calculate the molar mass of nitrogen trioxide

4) Calculate the molar mass of acetic acid CH3COOH

5) Calculate the number of moles of nitrogen trioxide in 67.8 grams

6) Calculate the number of grams in 2.5 moles of acetic acid

7)Calculate the number of moles in 36.2 g of acetic acid

Real life Stoichiometry

Air Bag Design

• Exact quantity of nitrogen gas must be produced in an instant.

• Use a catalyst to speed up the reaction

2 NaN3(s) 2 Na(s) + 3 N2(g)

6 Na(s) + Fe2O3(s) 3 Na2O(s) + 2 Fe (s)

Rocket Fuel The compound diborane (B2H6) was at one time considered for use as a rocket fuel. How many grams of liquid oxygen would a rocket have to carry to burn 10 kg of diborane completely? (The products are B2O3 and H2O).

B2H6 + 3 O2 B2O3 + 3 H2O

B2H6 + O2 B2O3 + H2OChemical equation

Balanced chemical equation

Water in Space

In the space shuttle, the CO2 that the crew exhales is removed from the air by a reaction within canisters of lithium hydroxide. On average, each astronaut exhales about 20.0 mol of CO2 daily. What volume of water will be produced when this amount of CO2 reacts with an excess of LiOH? (Hint: The density of water is about 1.00 g/mL.)

CO2(g) + 2 LiOH(s) Li2CO3(aq) + H2O(l)

X mL H2O = 20.0 mol CO2 (1 mol H2O) (18 g H2O) (1 mL H2O)(1 mol CO2) (1 mol H2O) (1 g H2O)

excess20.0 mol x g

X = 360 mL H2O