No Bell Ringer Today.
We will have a test tomorrow.
WS: Chemical Reactions and Equations
Part 1
1/19
1/26
WS: Word Equations and Formula
Equations
1/20
1/27
Quiz: Word Equations and Formula
Equations
1/21
1/21
WS: Chemical Reactions and Equations
Part 2
1/24
1/28
WS: Chemical Reactions and Equations
Part 3
1/25
1/31
Lab: Types of Reactions
1/28
1/31
WS: Chemical Reactions and Equations
Part 4
1/27
2/2
Test 6
2/10
2/10
WS: Moles and Molar Mass
2/11
2/18
WS - Practice with Mole–Mass-Numbers
of Atoms Conversions
2/14
2/21
WS – Stoichiometry: Mole-Mole
Conversions
2/15
2/22
Review for Test 7
12
For the reaction:
S8 + O2 æ SO2
how many moles of sulfur
are required to produce 15
mol of sulfur dioxide?
13
For the reaction:
Fe +
H2O æ Fe3O4 + H2
how many moles of iron are
required to produce 30 mol of
hydrogen gas? Be sure to
balance the equation
14
How many grams of mass are
in 34.5 moles of lead?
15
How many grams of mass are
23
there in 3.01 x 10 atoms of
carbon?
Bell Ringer
12-17-09
Write only the white and yellow.
Hydrochloric acid reacts with magnesium
hydroxide to produce magnesium chloride
and water according to the following
equation:
HCl + Mg(OH)2 æ MgCl2 + HOH
Balance the equation and determine
how many moles of hydrochloric acid
will be needed to produce 35 moles of
magnesium chloride.
Bell Ringer
12-18-09
Write only the white and yellow.
Sulfuric acid reacts with sodium
hydroxide according to the following
equation:
H2SO4 + NaOH → Na2SO4 +
H2O
Balance the equation, then determine the
mass (g) of H2SO4 that would be required
to react with 0.75 mol of NaOH.
Bell Ringer
1-4-10
Write only the white and yellow.
Magnesium chloride reacts with
calcium hydroxide as we see below:
MgCl2 + Ca(OH)2 →
Identify the type of reaction, predict the
products, and balance the equation.
Determine the mass (g) of MgCl2 that
would be required to react with 12.5 mol
of Ca(OH)2.
Limiting Reactants
•In the laboratory, a reaction is rarely
carried out with exactly the required
amounts of each of the reactants.
•In most cases, one or more reactants is
present in excess; that is, there is more
than the exact amount required to
react.
•Once one of the reactants is used up,
no more product can be formed.
Limiting Reactants
• The substance that is completely used up
first in a reaction is called the limiting
reactant.
• The limiting reactant is the reactant that
limits the amounts of the other reactants
that can combine and the amount of
product that can form in a chemical
reaction.
• The substance that is not used up
completely in a reaction is sometimes called
the excess reactant.
Limiting Reactants
• Consider the reaction between carbon
and oxygen to form carbon dioxide.
C + O2 → CO2
• According to the equation, one mole of
carbon reacts with one mole of oxygen to
form one mole of carbon dioxide.
• Suppose you could mix 5 mol of C with
10 mol of O2 and allow the reaction to
take place.
Limiting Reactants
•
•
•
The figure below shows that there is more oxygen
than is needed to react with the carbon.
Carbon is the limiting reactant in this situation, and
limits the amount of CO2 that is formed.
Oxygen is the excess reactant, and 5 mol of O 2 will be
left over at the end of the reaction.
Bell Ringer
Tuesday, 1-5-10
Write only the white and yellow.
Hydrogen gas reacts with oxygen gas
as we see below:
H2 + O2 →
Identify the type of reaction, predict the
product(s), and balance the equation.
If 4.0 moles of hydrogen react with 3.0
moles of oxygen, which is the limiting
reactant?
Percent Yield
• The amounts of products calculated in the
stoichiometric problems in this chapter so
far represent theoretical yields.
• The theoretical yield is the maximum
amount of product that can be produced
from a given amount of reactant.
• In most chemical reactions, the amount of
product obtained is less than the
theoretical yield.
Percent Yield
• There are many reasons for this.
– Some of the reactant may be used
in competing side reactions that
reduce the amount of the desired
product.
– Also, once a product is formed, it
often is usually collected in impure
form, and some of the product is
often lost during the purification
process.
Percent Yield
• The measured amount of a product
obtained from a reaction is called the
actual yield of that product.
• Chemists are usually interested in the
efficiency of a reaction.
• The efficiency is expressed by comparing
the actual and theoretical yields.
• The percent yield is the ratio of the actual
yield to the theoretical yield, multiplied by
100.
Percent Yield
Percent Yield
• The amounts of products calculated in the
stoichiometric problems in this chapter so
far represent theoretical yields.
• The theoretical yield is the maximum
amount of product that can be produced
from a given amount of reactant.
• In most chemical reactions, the amount of
product obtained is less than the
theoretical yield.
Percent Yield
• There are many reasons for this.
– Some of the reactant may be used
in competing side reactions that
reduce the amount of the desired
product.
– Also, once a product is formed, it
often is usually collected in impure
form, and some of the product is
often lost during the purification
process.
Percent Yield
• The measured amount of a product
obtained from a reaction is called the
actual yield of that product.
• Chemists are usually interested in the
efficiency of a reaction.
• The efficiency is expressed by comparing
the actual and theoretical yields.
• The percent yield is the ratio of the actual
yield to the theoretical yield, multiplied by
100.
Percent Yield
Percent Yield
• The amounts of products calculated in the
stoichiometric problems in this chapter so
far represent theoretical yields.
• The theoretical yield is the maximum
amount of product that can be produced
from a given amount of reactant.
• In most chemical reactions, the amount of
product obtained is less than the
theoretical yield.
Percent Yield
• There are many reasons for this.
– Some of the reactant may be used
in competing side reactions that
reduce the amount of the desired
product.
– Also, once a product is formed, it
often is usually collected in impure
form, and some of the product is
often lost during the purification
process.
Percent Yield
• The measured amount of a product
obtained from a reaction is called the
actual yield of that product.
• Chemists are usually interested in the
efficiency of a reaction.
• The efficiency is expressed by comparing
the actual and theoretical yields.
• The percent yield is the ratio of the actual
yield to the theoretical yield, multiplied by
100.
Percent Yield