the week before ch 8 test i made an outline of the whole chapter. i gave a copy to will brantly and he said it was very helpful, sorry for posting it so late but soccer never stops i guess here it is
Chris Mathews Chemistry notes Chapter ocho
Section uno I. Describing Chemical Reaction a. Chemical reaction-the process by which one or more substances are changed into one or more different substances. i. In chemical reactions, the original substances are the reactants and the results are products. ii. The law of conservation of mass must be followed 1. Aka… matter can be neither created nor destroyed b. Chemical reactions are often described by chemical equation i. Chemical equation- represents with symbols and formulas, the identities and relative molecular or molar amounts of the reactants and products in a chemical reactions. Big def. ii. Ex. (NH4)2Cr2o7 → N2 + Cr2O3 + 4H2O 1. That’s an equation baby II. Indications of a Chemical Reaction a. To be sure that substances have undergone chemical changes, they usually run chemical tests BUT there are also observations that can be made i. Evolution of energy as heat and light 1. A change in matter that releases heat or light strongly indicates a chemical reaction a. Ex. Fire uses oxygen to produce heat and light ii. Production of a gas 1. The evolution of gas bubbles also indicates a chemical reaction a. Ex. CO2 is released rapidly after baking soda is mixed with vinegar iii. Formation of a Precipate 1. Precipate-a solid that is produced as a result of a chemical reaction in solution and that separates from that solution iv. Color change 1. Usually when there exists a color change a chemical reaction has occurred III. Characteristics of chemical equations a. A proper equation can summarize any chemical reaction i. The equation must represent known facts 1. All reactants and products must be identified meaning listed as solid (s) etc. ii. Must contain the correct formulas for the reactants and products 1. This is going to be a huge part of the test ergo study up, use ch 7 for reference but know oxidation states and common rules such as oxygen is always -2 and therefore can’t be mixed with a halogen (quiz question) 2. Remember most elements are unlisted because they don’t form anything a. Exceptions are S8 and P4 3. Law of conservation of mass must be satisfied a. Atoms are neither created or destroyed so you may have to balance each equation with a coefficient i. Small whole number that appears in front of a formula in a chemical reaction. IV.
have to do it in sections Word and Formula Equations a. First step to writing chemical equation is to know all the players i. It is helpful, then, to write out a word equation 1. An equation in which the reactants and products in a chemical reaction are represented by words. a. Does not give quantities of reactants or products b. Ex. Methane + Oxygen → carbon dioxide + water i. Arrow in above equation most always means yield 2. Second step is to replace names with the appropriate symbols, Remember oxygen exists as a diatomic element a. Ex. CH4 (s) + O2 (g) → CO2 (g) + H2O (g) i. However this is not balanced ii. It is a formula equation-represents the reactants and products of a chemical reaction by their symbols or formulas 3. Now the third step is to satisfy the law of conservation of mass a. Therefore we must balance the equation with coefficients b. We all know how to balance equations i. Final answer ii. Ex. CH4 (s) + 2O2 (g) → CO2 (g) + 2H2O (g) 4. Additional symbols used in Chemical equations a. There are many expressions used to simplify formulas i. Upward arrow = gaseous product ii. Down arrow = precipate b. The condition under which the reaction takes place is also given i. Ex. Heat is shown by 1. Known as delta 2. For complete details go to the chart on page 266 ii. Temperature may also be written over the arrow c. Some reactants also have reverse reactions where the products interact and become the reactants. i. Reversible reaction-a chemical reaction in which the products reform the original reactants. d. Do sample problem A page 267 V. Significance of a Chemical Equation a. Chemical Equations are useful in giving us Quantitative info i. The Coefficients of a chemical reaction indicate relative, but not absolute, amounts of a product of reactant 1. Usually shows the smallest number of atoms that will satisfy the law of conservation of mass 2. The reactions can be enlarged, by using the right amount of coefficients. ii. The relative Masses of the reactants and products of a chemical reactions can be determined from the reactions coefficients 1. Recall that you can find the mass in grams by multiplying the substance by its molar mass a. 1 mol H2 * 2.02/mol H2 = 2.02 g H2 iii. The reverse reaction for a chemical equation has the same relative amounts of substances as the forward reaction 1. A chemical equation is like an algebra problem and therefore can be read and multiplied on either side a. What you do to one side, you have to do to the other (Mr. coach almost Dr. Weldon)
Balancing Chemical Equations a. Most equations can be balanced by inspection, but if you are stuck, use these simple rules. i. Identify names and reactants and write a word def. 1. Ex. Water → hydrogen + water ii. Write a formula equation 1. H2O (L) → H2(g) + O2 (g) iii. Balance according to the law of conservation of mass. 1. 2H2O (L) → 2H2(g) + O2(g) iv. check your work b. sample problems page 273
Section dos I. Synthesis Reactions- also known as composition reaction, two or more substances combine to form a compound i. A + X = AX b. Reactions of elements with oxygen and sulfur i. One simple type of synthesis reaction, is the combination with oxygen to form an oxide. 1. Almost all metals react with oxygen to form oxides a. Ex. When magnesium is burned it glows bright white and turns to a powder ii. The other group two elements react in a similar way. 1. The general equation is MO where m is the metal and o is the oxide a. Also occurs with sulfur in the formula MS to make sulfides c. Reactions of metals with Halogens i. Most metals form with halogens to form ionic or covalent compounds 1. The general formula is MX where m is the metal and x is the halogen d. Synthesis Reactions with Oxides i. Active metals are highly reactive 1. These metals mixed with oxygen will combine with water to form metal name plus hydroxide a. Ex. Calcium oxide + water → calcium Hydroxide 2. Nonmetal oxides react with water to produce oxyacids a. Sulfur dioxide + water → Sulfurous acid i. This is also known as acid rain 3. Metal oxides react with nonmetal oxides to form salts II. Decomposition Reactions a. A single compound undergoes a reaction that produces two or more simpler substances i. General formula is AX= A+X b. Decomposition of Binary Compounds i. The simplest decomposition reaction is one compound into its two elements 1. The decomposition of a substance by an electric current is called electrolysis c. Decomposition of metal carbonates i. when a metal carbonate is heated, it breaks down into a metal and carbon dioxide gas d. decomposition of metal hydroxides i. all metal hydroxides, except for group one metals, when heated produce a metal oxide and water e. decomposition of metal chlorates i. When metal chlorate is heated, decomposed to form metal chloride and oxygen f. Decomposition of acids i. Certain acids decompose into nonmetal oxides and water 1. Carbonic acids decompose to produce carbon dioxide and water 2. Sulfuric acid → sulfur trioxide and water III. Single Displacement Reaction a. Also known as replacement reaction, one element replaces a similar element in a compound i. takes place mostly in aqueous solutions ii. general formula is A+BX→AX+B or Y+BX→ BY+X b. Displacement of a metal in a compound by another metal i. when a more reactive metal comes along, it replaces the less reactive metal c.
last one Displacement of Hydrogen in water by a metal i. Group one metals react vigorously with water to form a metal hydroxide and hydrogen ii. Less reactive metals form with steam to make metal oxide and hydrogen gas d. Displacement of Hydrogen in an acid by a metal i. More active metals produce a hydrogen gas and a salt e. Displacement of halogens i. One halogen replaces another halogen 1. Each halogen can replace every halogen below it IV. Double Displacement Reactions a. The ions of two compounds exchange places in an aqueous solution to form two new compounds i. One is almost always a precipate, gas, or molecular compound i.e. water ii. General formula is AX+BY→ AY+BX b. Formation of a Precipate i. Occurs when the cations of one reactant combine with the anions of another to form an insoluble or slightly soluble compound. c. Formation of a Gas i. One of the products is also an insoluble gas that bubbles out of the mixture d. Formation of water i. Water is also a product V. Combustion Reactions a. A substance combines with oxygen, releasing a large amount of energy in the form of heat or light i. The burning of natural gas is a combustion reaction 1. Know this reaction 2. C3H8(g) + O2(g) → 3CO2 (g) + 4H2O(g)
Section Tres I. Activity Series of the Elements a. Activity-the ability of an element to react i. The more greatly an element reacts, the greater the activity ii. Activity series- a list of elements organized according to the ease with which the elements undergo certain chemical reactions. 1. for metals, greater activity means easier loss of electrons 2. for nonmetals, greater activity means greater ease of gaining electrons iii. the most active element in a series can replace all those under it and so on. 1. This is used to guess what will happen in a reaction a. Ex. 2Al(s) + 2ZnCl2(aq) → 3 Zn(s) + 2AlCl3(aq) i. Aluminum replaces zinc b. Co(s) + 3ZnCl2(aq) → no reaction i. Cobalt cannot replace sodium
good work will. and remember that in combustion reactions, the products are H2O and CO2
ReplyDeleteThis comment has been removed by the author.
ReplyDelete2C12H22O2 + 33O2 => 24C02 + 22H2O
ReplyDeleteThis comment has been removed by the author.
ReplyDeletec. 2Al(OH)3 (s) + 3H2SO4 (aq) ==> Al2(SO4)3(aq) + 6H2O
ReplyDeleteAnd products of combustion reactions are only CO2 when it is a carbohydrate.
Test tomorrow expect at least 8 calculations,one from each of the practice problems, but there will probably be more.
ReplyDeletethe week before ch 8 test i made an outline of the whole chapter. i gave a copy to will brantly and he said it was very helpful, sorry for posting it so late but soccer never stops i guess here it is
ReplyDeleteChris Mathews
Chemistry notes
Chapter ocho
Section uno
I. Describing Chemical Reaction
a. Chemical reaction-the process by which one or more substances are changed into one or more different substances.
i. In chemical reactions, the original substances are the reactants and the results are products.
ii. The law of conservation of mass must be followed
1. Aka… matter can be neither created nor destroyed
b. Chemical reactions are often described by chemical equation
i. Chemical equation- represents with symbols and formulas, the identities and relative molecular or molar amounts of the reactants and products in a chemical reactions. Big def.
ii. Ex. (NH4)2Cr2o7 → N2 + Cr2O3 + 4H2O
1. That’s an equation baby
II. Indications of a Chemical Reaction
a. To be sure that substances have undergone chemical changes, they usually run chemical tests BUT there are also observations that can be made
i. Evolution of energy as heat and light
1. A change in matter that releases heat or light strongly indicates a chemical reaction
a. Ex. Fire uses oxygen to produce heat and light
ii. Production of a gas
1. The evolution of gas bubbles also indicates a chemical reaction
a. Ex. CO2 is released rapidly after baking soda is mixed with vinegar
iii. Formation of a Precipate
1. Precipate-a solid that is produced as a result of a chemical reaction in solution and that separates from that solution
iv. Color change
1. Usually when there exists a color change a chemical reaction has occurred
III. Characteristics of chemical equations
a. A proper equation can summarize any chemical reaction
i. The equation must represent known facts
1. All reactants and products must be identified meaning listed as solid (s) etc.
ii. Must contain the correct formulas for the reactants and products
1. This is going to be a huge part of the test ergo study up, use ch 7 for reference but know oxidation states and common rules such as oxygen is always -2 and therefore can’t be mixed with a halogen (quiz question)
2. Remember most elements are unlisted because they don’t form anything
a. Exceptions are S8 and P4
3. Law of conservation of mass must be satisfied
a. Atoms are neither created or destroyed so you may have to balance each equation with a coefficient
i. Small whole number that appears in front of a formula in a chemical reaction.
IV.
have to do it in sections
ReplyDeleteWord and Formula Equations
a. First step to writing chemical equation is to know all the players
i. It is helpful, then, to write out a word equation
1. An equation in which the reactants and products in a chemical reaction are represented by words.
a. Does not give quantities of reactants or products
b. Ex. Methane + Oxygen → carbon dioxide + water
i. Arrow in above equation most always means yield
2. Second step is to replace names with the appropriate symbols, Remember oxygen exists as a diatomic element
a. Ex. CH4 (s) + O2 (g) → CO2 (g) + H2O (g)
i. However this is not balanced
ii. It is a formula equation-represents the reactants and products of a chemical reaction by their symbols or formulas
3. Now the third step is to satisfy the law of conservation of mass
a. Therefore we must balance the equation with coefficients
b. We all know how to balance equations
i. Final answer
ii. Ex. CH4 (s) + 2O2 (g) → CO2 (g) + 2H2O (g)
4. Additional symbols used in Chemical equations
a. There are many expressions used to simplify formulas
i. Upward arrow = gaseous product
ii. Down arrow = precipate
b. The condition under which the reaction takes place is also given
i. Ex. Heat is shown by
1. Known as delta
2. For complete details go to the chart on page 266
ii. Temperature may also be written over the arrow
c. Some reactants also have reverse reactions where the products interact and become the reactants.
i. Reversible reaction-a chemical reaction in which the products reform the original reactants.
d. Do sample problem A page 267
V. Significance of a Chemical Equation
a. Chemical Equations are useful in giving us Quantitative info
i. The Coefficients of a chemical reaction indicate relative, but not absolute, amounts of a product of reactant
1. Usually shows the smallest number of atoms that will satisfy the law of conservation of mass
2. The reactions can be enlarged, by using the right amount of coefficients.
ii. The relative Masses of the reactants and products of a chemical reactions can be determined from the reactions coefficients
1. Recall that you can find the mass in grams by multiplying the substance by its molar mass
a. 1 mol H2 * 2.02/mol H2 = 2.02 g H2
iii. The reverse reaction for a chemical equation has the same relative amounts of substances as the forward reaction
1. A chemical equation is like an algebra problem and therefore can be read and multiplied on either side
a. What you do to one side, you have to do to the other (Mr. coach almost Dr. Weldon)
Balancing Chemical Equations
ReplyDeletea. Most equations can be balanced by inspection, but if you are stuck, use these simple rules.
i. Identify names and reactants and write a word def.
1. Ex. Water → hydrogen + water
ii. Write a formula equation
1. H2O (L) → H2(g) + O2 (g)
iii. Balance according to the law of conservation of mass.
1. 2H2O (L) → 2H2(g) + O2(g)
iv. check your work
b. sample problems page 273
Section dos
I. Synthesis Reactions- also known as composition reaction, two or more substances combine to form a compound
i. A + X = AX
b. Reactions of elements with oxygen and sulfur
i. One simple type of synthesis reaction, is the combination with oxygen to form an oxide.
1. Almost all metals react with oxygen to form oxides
a. Ex. When magnesium is burned it glows bright white and turns to a powder
ii. The other group two elements react in a similar way.
1. The general equation is MO where m is the metal and o is the oxide
a. Also occurs with sulfur in the formula MS to make sulfides
c. Reactions of metals with Halogens
i. Most metals form with halogens to form ionic or covalent compounds
1. The general formula is MX where m is the metal and x is the halogen
d. Synthesis Reactions with Oxides
i. Active metals are highly reactive
1. These metals mixed with oxygen will combine with water to form metal name plus hydroxide
a. Ex. Calcium oxide + water → calcium Hydroxide
2. Nonmetal oxides react with water to produce oxyacids
a. Sulfur dioxide + water → Sulfurous acid
i. This is also known as acid rain
3. Metal oxides react with nonmetal oxides to form salts
II. Decomposition Reactions
a. A single compound undergoes a reaction that produces two or more simpler substances
i. General formula is AX= A+X
b. Decomposition of Binary Compounds
i. The simplest decomposition reaction is one compound into its two elements
1. The decomposition of a substance by an electric current is called electrolysis
c. Decomposition of metal carbonates
i. when a metal carbonate is heated, it breaks down into a metal and carbon dioxide gas
d. decomposition of metal hydroxides
i. all metal hydroxides, except for group one metals, when heated produce a metal oxide and water
e. decomposition of metal chlorates
i. When metal chlorate is heated, decomposed to form metal chloride and oxygen
f. Decomposition of acids
i. Certain acids decompose into nonmetal oxides and water
1. Carbonic acids decompose to produce carbon dioxide and water
2. Sulfuric acid → sulfur trioxide and water
III. Single Displacement Reaction
a. Also known as replacement reaction, one element replaces a similar element in a compound
i. takes place mostly in aqueous solutions
ii. general formula is A+BX→AX+B or Y+BX→ BY+X
b. Displacement of a metal in a compound by another metal
i. when a more reactive metal comes along, it replaces the less reactive metal
c.
last one
ReplyDeleteDisplacement of Hydrogen in water by a metal
i. Group one metals react vigorously with water to form a metal hydroxide and hydrogen
ii. Less reactive metals form with steam to make metal oxide and hydrogen gas
d. Displacement of Hydrogen in an acid by a metal
i. More active metals produce a hydrogen gas and a salt
e. Displacement of halogens
i. One halogen replaces another halogen
1. Each halogen can replace every halogen below it
IV. Double Displacement Reactions
a. The ions of two compounds exchange places in an aqueous solution to form two new compounds
i. One is almost always a precipate, gas, or molecular compound i.e. water
ii. General formula is AX+BY→ AY+BX
b. Formation of a Precipate
i. Occurs when the cations of one reactant combine with the anions of another to form an insoluble or slightly soluble compound.
c. Formation of a Gas
i. One of the products is also an insoluble gas that bubbles out of the mixture
d. Formation of water
i. Water is also a product
V. Combustion Reactions
a. A substance combines with oxygen, releasing a large amount of energy in the form of heat or light
i. The burning of natural gas is a combustion reaction
1. Know this reaction
2. C3H8(g) + O2(g) → 3CO2 (g) + 4H2O(g)
Section Tres
I. Activity Series of the Elements
a. Activity-the ability of an element to react
i. The more greatly an element reacts, the greater the activity
ii. Activity series- a list of elements organized according to the ease with which the elements undergo certain chemical reactions.
1. for metals, greater activity means easier loss of electrons
2. for nonmetals, greater activity means greater ease of gaining electrons
iii. the most active element in a series can replace all those under it and so on.
1. This is used to guess what will happen in a reaction
a. Ex. 2Al(s) + 2ZnCl2(aq) → 3 Zn(s) + 2AlCl3(aq)
i. Aluminum replaces zinc
b. Co(s) + 3ZnCl2(aq) → no reaction
i. Cobalt cannot replace sodium
of course you will have to make the indentions yourself good luck guys
ReplyDeleteTEST is TOMMOROW! get to studying boys, for it's going to be a hard one.
ReplyDeletenow, back to the blog. here is a good website on balancing equations.
http://richardbowles.tripod.com/chemistry/balance.htm
and here is a good site on the types of chemical reactions.
http://www.usoe.k12.ut.us/curr/science/sciber00/8th/matter/sciber/chemtype.htm
also, thank you chris for your novel of notes, mastered only by Homer's "Iliad" in length.
http://misterguch.brinkster.net/6typesofchemicalrxn.html
ReplyDeleteGood site for chemical reactions
Site explaining percent yield:
ReplyDeletehttp://www.wikihow.com/Calculate-Percent-Yield-in-Chemistry
Good luck to everyone on the test.
P.S. Colby, it's TOMORROW not TOMMOROW
Jeez, Chris, you went all out. Here's a refresher video on balancing equations.
ReplyDeletehttp://www.teachertube.com/viewVideo.php?video_id=139030
http://go.hrw.com/activities/frameset.html?main=1882.html
ReplyDeletea link to the chapter 8 quiz on the book's website, you can easily find the ch 9 one too
For more practice on balancing equations
ReplyDeletehttp://www.webqc.org/balance.php
Here are some stoichiometry problems to practice
ReplyDeletehttp://www.standnes.no/chemix/examples/stoichiometry-problems-chemistry.htm
Don' forget that Ag, Pt, Au of the Activity series are fairly reactive and only form oxides inderictly
ReplyDeletehttp://richardbowles.tripod.com/chemistry/balance.htm
ReplyDeletethis will help you practice balancing equations
Here is some more practice on balancing equations.
ReplyDeletehttp://www.docstoc.com/docs/15492931/Balancing-Equations-Worksheet
chemisrty review:
ReplyDeletehttp://www.biology.arizona.edu/biochemistry/tutorials/chemistry/main.html
http://www.chemistryexplained.com/Ce-Co/Chemical-Reactions.html
ReplyDeleteHere is a good site on single displacement reactions, and other types of reactions