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8/12/2019 IntroToChem_StoichFollowAlongNotes

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AP Chemistry: Chapter 1-3 Notes Outline

Objectives:

Memorize key ions and atoms symbols and their charges

Matter

Be able to count and use significant figures in calculations Be able to convert measurements using dimensional analysis

Be able to name ionic compounds

Be able to name acids

Balance chemical equations

Use dimensional analysis to solve stoichiometric problems

Use dimensional analysis to do limiting reactant problems

Use dimensional analysis to calculate percent yield

Calculate percent composition

Calculate empirical and molecular formulas

Memorize Key ions an atoms:

You must score a 9!"## to receive credit$ %ee memory sheet for these items$

Matter:

&ure %ubstances vs Mi'tures

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Mi!tures

"omo#eneous

$e%inition

&!amples

"etero#eneous

$e%inition

&!amples

'eparation o% Mi!tures

(ase on Physical Properties

$istillation

Chromato#raphy

'olubility

Others

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'i#ni%icant )i#ures:

*hy significant figures+

Rules for counting significant figures

1. All nonzero numbers count

2. Leading zeros dont count3. Trailing zeros count if there is a decimal

4. Trailing zeros dont count if there is no decimal

,'amples of counting significant figures:

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.ules for calculating /ith significant figures:

"$ 0ddition and %ubtraction: You are only as good as your least accurate place value)$ Multiplication and 1ivision: You are only as good as your least accurate number o% si#ni%icant %i#ures

,'amples of calculations involving significant figures

Convert *ith $imensional Analysis2he principle is that you are multiplying several fractions tog tether3 but each is the same measurement so that you are essentially multiplying

by "$

1imensional 0nalysis .ules:

"$ 0ll numbers must be /ritten as fractions4this includes numbers that are given4so 5$6 grams is"

6$5 g

)$ 0ll subsequent multipliers are /ritten such that the units must cancel: 7or e'ample: lbsg

lbx

g#"$#

88

"

"

6$5=

/

/$ otice ho/ the

grams cancel

-$ 0ll numbers on the top of a series of fractions are multiplied and all numbers on the bottom of a series of fractions are divided$ 7ore'ample:

143.55mL

1x

1L

1000mLx0.2642gal

1Lx4qt

1galx2pt

1qt=0.30341pt. In your calculator you would: 143.55*0.264*4*2/1000=.

2ype ": ne 1imensional &roblems

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2ype ) : *orking /ith multiple dimensions4Convert miles per hour into meters per second$

2ype -: 0rea and ;olume:


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Namin# +onic Compouns

Rules1. Name ation

2. !se Roman Numerals if the metal is a transition metal "#xce$tions% &n' Ag' Al(

3. Name the Anion ")t ma* be a $ol*ion(

,'amples: 7rom ame to 7ormula

,'amples: 7rom 7ormula to ame

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Namin# Acis

Rules% Al+a*s chec, the anion of the acid1. )f the anion ends in ide change to h*do--------ic acid

2. )f the anion ends in ate change to --------ic acid

3. )f the anion ends in ite change to --------ous acid4. )f the anion is $er----ate change to $er-----ic acid

,'amples

(alance chemical e,uations

Balance the follo/ing:

>>C5


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'toichiometry Problems usin# imensional Analysis

Rules1. Al+a*s start +ith a balanced euation

2. /rite +hat *ou ,no+ underneath the chemical that is ,no+n "0.23grams(

3. lace a uestion mar, "( underneath +hat *ou are loo,ing for.4. !se dimensional anal*sis to conert to the chemical *ou are tr*ing to find information about. Note that *ou +ill most li,el* need to

use the molemole ratio "also called the stoichiometric ratio( to conert from one chemical to another.

&!amples


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imitin# .eactant Problems

Rules1. onert all reactants to moles

2. 5iide b* the coefficient in the balanced euation

3. The chemical +ith the lo+est number of moles is the limiting reactant "LR(4. !se the LR for all further calculations

&!ample:

*hen ""8$# g of iron and ))$6 g of chlorine gas reacts3 ironD chloride is formed$a$ *rite a balanced equation

b$ *hat is the limiting reactant+c$


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--$5 grams of sulfur dio'ide reacts /ith $- grams of /ater to form sulfurous acid$

a$ *rite a balanced equation$b$ *hat is the limiting reactant+

c$


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Percent Composition

7ind the percentage composition of a chemical by finding the total molar mass of the compound find the mass percent of each element in acompound:

,'ample:


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Molecular )ormulas

"$ Molecular 7ormulas are >>>>>>>> >>>>>>>>>not Fust the simplest >>>>>>>>>>>>>)$ the molar mass of the empirical formula ,7D is al/ays a multiple of the M*$

-$ Use the M* to determine by /hat factor you need to multiply the empirical formula to find the molecular formula$

,'ample

Determine the molecularformula for a compound that contains 22.5% Na, 30.4% P and 47.1% O and a molar mass of 306 g/mol

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,'ample: Comple' Molecular and ,mpirical 7ormula &roblems4Combustion &roblems

Many homes in rural 0merica are heated by propane gas3 a compound that contains only carbon and hydrogen$ Complete combustion

of a sample of propane produced )$58" grams of carbon dio'ide and "$88) grams of /ater as the only products$ 7ind the empirical

formula of propane$

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Galactose GalD also called brain sugarD is a type of sugar found indairy products3 in sugar beetsand othergumsand mucilages$

*hen )$-" grams of galactos is completely burned it produces -$9- grams of carbon dio'ide and "$-A9 grams of /ater$ 2he molarmass of galactose is bet/een "6) g!mol and "A5 g!mol$ *hat is the empirical and molecular formula of galactose+

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http://en.wikipedia.org/wiki/Sugarhttp://en.wikipedia.org/wiki/Dairy_producthttp://en.wikipedia.org/wiki/Sugar_beethttp://en.wikipedia.org/wiki/Gumhttp://en.wikipedia.org/wiki/Mucilagehttp://en.wikipedia.org/wiki/Sugarhttp://en.wikipedia.org/wiki/Dairy_producthttp://en.wikipedia.org/wiki/Sugar_beethttp://en.wikipedia.org/wiki/Gumhttp://en.wikipedia.org/wiki/Mucilage

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