introduction to stoichiometryimages.pcmac.org/sisfiles/schools/ga/houstoncounty/... ·...
TRANSCRIPT
Introduction to Stoichiometry
Reaction Stoichiometry
The relationships between reactants and
products in a chemical reaction are
studied through reaction stoichiometry.
Reaction Stoichiometry and
Chemical Equations All reaction stoichiometry begins with a
balanced chemical equation and the law of
conservation of matter.
Recall that balanced chemical equations
give us a relative number of moles of
reactants and products
Reaction Stoichiometry Problem
Types Mole-Mole: Given and unknown quantities
are amounts measured in moles
– Mol X Mol Y
Mass-Mole: Given is an amount measured
in moles. Unknown is a mass measured
in grams.
– Mol X Mass (g) Y
– Mass (g) X Mol Y
Reaction Stoichiometry
Problem Types Mass-Mass: Given and unknown quantities are measured in grams.
–Mass (g) X Mass (g) Y
Solving Reaction
Stoichiometry Problems To solve a stoichiometry problem you will
use mole ratio and Molar mass as the
conversion factors.
Molar mass is the conversion factor used
to relate one mole of a substance to its
mass in grams.
Molar mass is used to convert
g X mol X or
mol X g X
The mole ratio is a conversion factor used
to describe the relative amounts of two
different substances in a chemical
reaction. It is derived from the balanced
chemical equation.
Mole ratio is used to convert
mol X mol Y
Practice Problems Mole-Mole Ammonia, NH3, is widely used as a fertilizer and in may
household cleaners.
How many moles of ammonia (nitrogen trihydride) are
produced when 6 mol of hydrogen gas react with an
excess of nitrogen gas?
Practice Problems Mole-Mole Ammonia, NH3, is widely used as a fertilizer and in may household
cleaners. How many moles of ammonia are produced when 2 mol of
nitrogen gas react with an excess of hydrogen gas?
N2 + H2 NH3
Practice Mass-Mole When magnesium burns in air, it combines with oxygen
to form magnesium oxide. What mass in grams of
magnesium oxide is produced from 2.00 mol of
magnesium?
In a spacecraft, the carbon dioxide exhaled by astronauts can be
removed by its reaction with lithium hydroxide. Lithium carbonate
and water are produced during this reaction. How many moles of
Lithium hydroxide are required to react with 80.0 g of CO2, the
average amount exhaled by a person each day?
The decomposition of potassium chlorate yields
potassium chloride and oxygen gas. It is used as a
source of oxygen in the laboratory. How many moles of
potassium chlorate are needed to produce 32.0 g of
oxygen?
Practice The decomposition of potassium chlorate into potassium chloride and
oxygen is used as a source of oxygen in the laboratory. How many moles
of potassium chlorate are needed to produce 15 mol of oxygen?
KClO3 KCl + O2
What mass of glucose can be produced from a photosynthesis reaction that
occurs using 10 mol CO2?
CO2 + H2O C6H12O6 + O2 What mass of carbon dioxide, in grams, is needed to react with 40.0g of
water in the photosynthesis reaction?
CO2 + H2O C6H12O6 + O2 In a spacecraft, the carbon dioxide exhaled by astronauts can be removed
by its reaction with h hydroxide. How many grams of Lithium hydroxide are
required to react with 20.0 mol of CO2, the average amount exhaled by a
person each day?
CO2 + LiOH Li2CO3 + H2O
Mass-Mass
AgNO3 + BaCl2 AgCl + Ba(NO3)2
If 5.0 grams of silver (I) nitrate react, how
many grams of barium chloride will also
react?
Mass-Mass
AgNO3 + BaCl2 AgCl + Ba(NO3)2
– 5.0g AgNO3 = _____g BaCl2
– 5.0g AgNO3 = _____g AgCl
N2 + H2 NH3
– 50.0 g N2 = _____g NH3
– 100.0 g N2 = _____g H2
KClO3 KCl + O2
– 25.0 g KClO3 = _____g KCl
– 20.0g KClO3 = _____g O2