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SNC2P
Getting Started
Science
• Science is a way of gaining knowledge and understanding of our world.
• It is the desire to understand how and why things work.
• Science, in its purest form, is done out of simple curiosity.
• It is concerned with knowledge and ideas.
Technology
• Technology is applying knowledge to make products that will improve the quality of our lives.
• It answers human needs.
• Technology is concerned with the production of things.
Hazardous Household Waste
• Household hazardous waste (hhw) is any substance that may be harmful to you, animals, or the environment when not properly handled.
• Hhw can be in the form of solids, liquids, or gases.
• Misuse of hhw can lead to pollution of groundwater, lakes, rivers, and soil.
• An easy way to identify hhw is to look at the label and read disposal instructions.
Hazardous Household Product Symbols
• Containers labeled with this symbol are explosive. They may produce deadly fumes or vapors when exposed to air Keep away from heat.
• Any product with this symbol is flammable. Keep away from sources of spark or flame.
Hazardous Household Product Symbols
• Products with this symbol are poisonous or lethal if swallowed, inhaled, or absorbed
• A product with this symbol is corrosive and can cause burns to your skin and eyes and can eat away at other material.
Degree of Danger
• The degree of danger of hazardous household products is indicated by the shape outlining the symbol.
• Danger –
• Warning –
• Caution –
Workplace Hazardous Materials Information System
WHMIS
• Workplace Hazardous Materials Information System was implemented in 1988 as a national system to provide information on hazardous materials used in the workplace.
• The key elements of the system are the material safety data sheets (msds), the simple labeling system, and the workers education program.
•The WHMIS Board contains all the symbols with
explanations.
• There is also a binder with the data sheets for
each chemical in the facility.
• This is a container of toluene.
• You can see the WHMIS label clearly by the dashed border and the hazard symbols.
WHMIS Symbols
• Compressed Gas – materials that are normally gaseous and kept under pressure. These may explode if dropped or exposed to pressure or heat.
• Flammables and Combustibles – materials which ignite easily and will continue to burn after being exposed to flame or spark.
WHMIS Symbols Continued• Oxidizing Material – materials
which can cause other materials to burn. Will cause combustibles to react violently Can cause skin and eyes to burn.
• Toxic, immediate and severe effects – poisonous and potentially fatal materials that will cause severe harm if inhaled, ingested, or absorbed (even in small amounts).
WHMIS Symbols Continued• Toxic, long term effects –
materials which may have harmful effects after repeated exposure. May cause death or permanent injury, birth defects, sterility, cancer, or even allergies.
• Biohazardous infectious – Infectious agents or biological toxins causing serious disease or death. Includes viruses, yeasts, molds, bacteria, parasites.
WHMIS Symbols Continued• Corrosive Materials – materials that
react and cause skin irritation, severe burns and tissue damage, lung damage, eye irritation or blindness, as well as environmental damage from fumes.
• Dangerously reactive material – these have unexpected reactions. They may react with water. They may be unstable in air. They may explode if exposed to shock or heat. May release toxic fumes or burn unexpectedly.
Labware
Beaker
Beaker tongs
Evaporating dish
Watch Glass
Wash bottle
Test tube
Test tube clamps
Test tube rack
Graduated cylinder
Florence flask
Erlenmeyer flask
Stirring rod
Pipette
Funnel
Wire screen (gauze)
Ring clamp
Ring stand
Goggles
Crucible
Crucible tongs
Triple Beam Balance
Pestle
Mortar and pestle
Bunsen Burner
Scupula and handle
Clay triangle
Striker
Set up for heating
Thermometer
Lab Safety
Lab Safety
• Always be safety conscious. Move around the laboratory in a safe and slow manner.
• Never perform unauthorized experiments. Follow all instructions, verbal and written.
• Plan ahead. Become familiar with all the health and safety hazards of the equipment and chemicals to be used. If you are not comfortable, inform the teacher.
• Know the location of the safety equipment and fire exits. Use this equipment only in emergencies.
• Report all accidents – no accident is too small to report. Do not attempt to clean up a spill until checking with the teacher. Broken glassware must be dealt with immediately. Inform teacher of all broken glassware.
• Safety glasses must be worn while working with any chemical. It is recommended that you do not wear contact lenses during labs where chemicals will be used. If you get chemical in your eye, do not wait for the teacher, have a peer take you straight to the eyewash station and flush eyes for 5 minutes.
• If you get chemical splashed or spilled on your skin, flush it with water at one of the sinks around the room. If irritation or pain develops, see a physician.
• Wash hands thoroughly before leaving the laboratory.
• If you get chemicals on your clothes, wash the clothes, but not with good clothing. You should not wear loose clothing in the lab, nor should you wear good clothing.
• Handle all chemicals as if they were dangerous.
• Tie back long hair.
• Do not consume food or drink while in the lab. Never taste the chemicals.
• Keep workstations clear of all books, bags, and clothing. Workstations should have only the materials needed for the lab. Do not sit on the workstation counter
• Clean all equipment thoroughly and put it back where you found it.
• Follow all directions regarding the disposal of chemicals and solutions. Not everything goes down the sink. Do not put used chemicals or solutions back into the original container.
• Clean your lab station before leaving the classroom.
Science 10
Chemical Reactions
Classification of Matter
• Matter can be classified into two main categories, pure substances and mixtures
Pure Substances
• Pure substances are made up of only one component.
• A pure substance may be further classified as either an element or a compound.
An Element
• An element is a type of matter that is made up only of one type of atom.
• Some examples are gold, silver, lead, and mercury.
• Elements are given chemical symbols to represent them.
• The first letter (or only letter) is always capitalized.
• The second letter (if there is one) is always lower case.
H is Hydrogen
O is Oxygen
Be is Beryllium
Ni is Nickel
Compounds
• Compounds are materials that are made of two or more types of atoms joined chemically.
• Some examples are water (H2O), carbon dioxide (CO2) and sodium chloride (NaCl).
Mixtures
• In a mixture, different substances are brought together without creating a new substance. The pieces mix but do not join.
• In a mixture, each component retains its own identity, however, the ratio of the components that make up the mixture can change.
• A regular bag of M& M's Chocolate Candies contains 20% orange and 13% brown candies, with the remaining 67% being split (unevenly) between green, blue, red and yellow. When M & M's sell for Halloween, the ratios of the colors change such that only orange and brown M & M's appear in the bag. This ability to change ratios is a characteristic of a mixture.
Properties of Matter
• There are two characteristics or properties that help determine forms of matter – physical properties and chemical properties.
Physical Properties of Matter• Physical properties describe what the
material is like. These are visible features that can be observed or measured.– State – solid, liquid, gas, plasma– Colour– Density, viscosity– Hardness, brittleness– Taste, odour, texture, lustre, clarity– Melting and boiling points– Ductility (bendable) and malleability (able to be
hammered)
Chemical Properties of Matter
• Chemical properties explain how a material behaves and reacts in relation to other materials.– Types of bonds– Reactivity– Isotopes formed
Changes in Matter
• Chemists classify changes in matter into two categories, physical change and chemical change.
Physical change
• A physical change when there is no new product formed. The particles of the starting substance are not changed. A physical change can easily be reversed.
Chemical Change• In a chemical change, the substance
changes identity into something else.
Clues that a Chemical Change Took Place
A new colour appearedHeat or light was given offBubbles of gas were given offA precipitate formedThe change is difficult to reverse
The Atom
• The atom is the smallest particle of an element that retains all of the properties of that element.
• The atom has three subatomic particles: the proton, the electron, and the neutron.
Element Names
• All known elements have names. These names are from several sources.
• Some names have been around for many years. They have a Latin or Greek Origin.
• Chlorine comes from the word chloros which means yellow-green.
More on Element Names
• Some elements are named after important scientists.
• Einsteinium• Curium
• Some elements are named after places or planets.
• Uranium and Mercury• Californium
Even More on Element Names
• Some more recent elements have not been named yet.
• Elements 110 to 114
Element Symbols
• Element symbols can be an abbreviation of the element’s name.
• Carbon is C• Nitrogen is N• Calcium is Ca• Magnesium is Mg
More on Element Symbols
• Element symbols can also be an abbreviation of the ancient name.
• Copper is Cu• Tungsten is W
Subatomic Particles
• A proton is a positively charged particle found in the nucleus. It is partly responsible for the mass of an atom.
• A neutron is a particle with no charge found in the nucleus of an atom. It is partly responsible for the mass of an atom.
• An electron is a negatively charged particle found outside the nucleus. Electrons are very small and do not add much to the mass of an atom.
Atomic Information From The Periodic Table
Atomic Charge
• Atoms are neutral, which means that there is no overall charge.
• The number of protons is equal to the number of electrons.
Protons Minus Electrons Equals
Charge
The Periodic Table
The Periodic Table
• The Periodic Table is the central tool of the chemist, but it is used by scientists in all fields of study.
• It was developed by Russian Scientist, Dmitri Mendeleev, in the 1800s.
• The more modern version of the table is credited to Henry Mosely.
The Periodic Table
• The periodic table is essentially a list of known elements. It gives information about each element and for that reason it is a very valuable tool.
Arrangement of the Periodic Table
• The horizontal rows (periods) represent a series of elements with increasing weight and changing properties.
Arrangement of the Periodic Table
• The vertical columns represent a series of elements with similar chemical and physical properties.
• The column are called families and each family has a specific name.
Examples of Some Families on the Periodic Table
Metals and Nonmetals• Elements on the Periodic Table can be divided into
metals and nonmetals. Metals are found on the left side of the zigzag line. Nonmetals are found on the right side of the zigzag line.
Metalloids
• Elements that touch either side of the zigzag line have some metal properties and some nonmetal properties. These are called metalloids.
Steps for Drawing Atoms
1. Find the element on the periodic table. How many protons does it have?
2. Because atoms are neutral, the number of electrons will equal the number of protons
3. Write the number of protons in the center.
4. Colour in the electrons. Start with the two closest to the nucleus and work outwards.
Drawing Atoms
• The first ring around the nucleus can hold a maximum of 2 electrons.
• The second ring around the nucleus can hold a maximum of 8 electrons.
• The third ring can around the nucleus can hold a maximum of 8 electrons.
• The fourth ring around the nucleus can hold a maximum of 18 electrons.
Electron Shells for the First 20 Elements
Making Ions
• The goal of every element is to have a full outer shell.
• Electrons are gained or lost in order to attain a complete outer shell.
Making Negative Ions
• Chlorine has 17 electrons. Seven of those electrons are in the outer shell. In order for Chlorine to have a complete out shell it has to gain one electron or lose seven electrons. It will gain one electron.
Making Positive Ions
• Sodium has 11 electrons. One of those electrons is in the outer shell. In order for sodium to have a complete outer shell it would have to gain seven electrons or lose one electron. It loses one electron.
Valence Electron Trends• Elements in the Alkali Metal Family (H, Li, Na, K, Rb,
Cs, and Fr) tend to lose 1 electron.• Elements in the Alkaline Earth Metal Family (Be, Mg,
Ca, Sr, Ba, and Ra) tend to lose 2 electrons.• Elements in the Boron Family (B, Al, Ga, In, and Ti)
tend to lose 3 electrons.
Valence Electron Trends
• Elements in the Carbon Family (C, Si, Ge, Sn, Pb) can gain or lose 4 electrons.
• Elements in the Nitrogen Family (N, P, As, Sb, Bi) tend to gain 3 electrons.
• Elements in the Oxygen Family (O, S, Se, Te, Po) tend to gain 2 electrons.
• Elements in the Halogen Family (F, Cl, Br, I, At) tend to gain 1 electron.
• Elements in the Noble Gas Family (He, Ne, Ar, Kr, Xe, Rn) do not tend to gain or lose electrons as their outer shells are already complete.
How to Draw Electron Dot Diagrams
• Imagine a square around the element symbol.
• Determine the number of valence electrons. – Alkali Metals have 1– Alkaline Earth Metals
have 2– Boron Family has 3
– Carbon Family has 4– Nitrogen Family has
5– Oxygen Family has 6– Halogen Family has
7– Noble Gas Family
has 8
More on How to Draw Electron Dot Diagrams
• When filling the sides with electrons, each side gets one electron before any side gets two.
• Start at the top and work clockwise around the box.
• Once each side of the box has two electrons, the shell is full.
• Beryllium
Be• Boron
B• Silicon
Si• Nitrogen
N
Forming Ions
• In an atom the number of protons equals the number of electrons.
• If electrons are added to an atom, the atom now has more negatives than positives. It has a negative charge. This is an anion.
• If electrons are removed from an atom, the atom now has more positives than negatives. It has a positive charge. This is a cation.
Naming Ions
• To name a Cation (positively charged ion), write the element name followed by the word ion.
Mg2+is calledMagnesium
Ion
• To name an Anion (negatively charged ion), write the name of the element and change the ending to “ide”
S2-is calledSulfide
Writing Ionic Symbols From Names
• When given the name of an ion and the ending does not have “ide”, then you know this is a positive ion.
• Write the element’s symbol with a positive charge (recall the valence electron trends to know what the charge is).
The symbol for Potassium Ion is
K1+
• When given the name of an ion that ends in “ide”, you know it is a negative ion.
• Write the element’s symbol with a negative charge (recall the valence electron trend to know what the charge is).
The symbol forNitride is
N3-
Transition Metals
• The elements in columns 3 to 12 are called the Transition Metals.
• Transition Metals are always positive.• To know what the charge is you will
have to look at the Roman Numeral in the name.
Iron (III) means Fe3+
Nickel (II) means Ni2+
Traditional and Stock System Names of Transition Metals
• You will be given a table of traditional names for transition metals.
• Some examples of traditional names are Ferrous (Fe2+) and Ferric (Fe3+).
• The system we mostly use in this class is the Stock System.
• In the Stock System, Fe2+would be Iron (II) and Fe3+would be Iron (III).
Forming Ionic Compounds
• Substances that are composed of cations and anions are called ionic compounds (compounds made up of ions).
• When the ions combine the overall charge of the compound that is formed must be neutral.
K+ and Cl-
will combine to form
KCl
Forming Ionic Compound Examples
• Ca2+ and Cl1- will form
CaCl2
Because it will take two negative chlorines to balance one positive calcium.
• Na+ and S2- will form
Na2S
Because it will take two positive sodiums to balance one negative sulfur.
• Al3+ and P3- will form
AlP
Because it will take one positive aluminum to balance one negative phosphorus.
• Al3+and O2- will form
Al2O3
Because it will take two positive aluminums to balance three negative oxygens.
The Trick to Forming Ionic Compounds
Be2+ and P3-
Take the number part of the charge and put it on the bottom left hand side of the other ion.
Be 3 P 2
Polyatomic Ions
• Atoms can combine in groups to form ion complexes. These are called polyatomic ions.
• An example of a polyatomic ion is Phosphate (PO4)3-
• Other examples are Sulfite (SO3)2- and Ammonium (NH4)1+
• There is a table of common polyatomic ions that will be available for you to use.
Forming Compounds Using Polyatomic Ions
• The trick that was used to make binary ionic compounds (compounds made from 2 ions) can also be used to form polyatomic compounds.
Mg2+ and (PO4)3-
forms
Mg3 (PO4)2
Naming Ionic Compounds When Given The Formula
• Identify the ions in the compound
• Name the ions in the compound
• Change the ending on the second element to “ide”
Na2S
Sodium and Sulfur
Sodium Sulfide
Another Example of Naming Ionic Compounds When Given The
Formula• Identify the ions in
the compound• Name the ions in the
compound• Change the ending
on the second element to “ide”
KCl
Potassium and Chlorine
Potassium Chloride
Another Example of Naming Ionic Compounds When Given The
Formula• Identify the ions in
the compound• Name the ions in the
compound• Change the ending
on the second element to “ide”
CaBr2
Calcium and Bromine
Calcium Bromide
An Example of Naming a Polyatomic Compound
• Identify the ions in the compounds.
• Name the ions in the compound (use the polyatomic ion chart).
• Put the two names together
Li(NO2)
Lithium and Nitrite
Lithium Nitrite
An Example of Naming a Compound
That has a Transition Metal • Identify the ions in the
compounds.• Name the ions in the
compound (remember that transition metals have to have a roman numeral in their name).
• Put the two names together
Ag(Cr2O7)
Silver (II) and Dichromate
**Dichromate has a charge of –2 and it only take one silver to cancel that charge out, silver must be +2
Silver (II) Dichromate
Writing a Compound Formula When Given the Name
• Identify the ions in the formula
• Write down the symbols and determine the charge using the valence electron trends
• Put the two ions together (cation goes first)
• Sodium Nitrate
Made up of sodium ion and Nitrate ion
• Sodium ion is Na+
Nitrate ion is NO3-
• Na+ and NO3- form
NaNO3
Another Example of Forming a Compound from a Name
• Identify the ions in the formula
• Write down the symbols and determine the charge using the valence electron trends
• Put the two ions together (cation goes first)
Copper (II) Chloride
made up of Copper (II) and Chloride
Copper (II) is Cu2+
Chloride is Cl-
Cu2+ and Cl-1 form
CuCl2
Forming Covalent Compounds
• Atoms that share electrons rather than take or give them up are bonded covalently.
• Neither atom is strong enough to take the electrons from the other.
• Covalent bonds often happen between two negatively charged ions.
• Naming covalent molecules is different than naming ionic compounds.
• Prefixes are used to indicate how many of each atom are in the molecule.
Covalent Molecule Prefixes
• Mono = 1• Di = 2• Tri = 3• Tetra = 4• Penta = 5• Hexa = 6• Hepta = 7• Octa = 8
Covalent Molecule Examples
• An example of a covalent molecule is P2O5
This would be called Diphosphorus Pentaoxide
• Another Example is N3O5.
This would be called Trinitrogen Pentaoxide
Using “Mono” with Covalent Molecules
• When there is only one atom of the first element, mono is not used
CO2 is called
Carbon Dioxide not Monocarbon Dioxide
• When there is only one atom of the second element, mono is used.
N2O is called
Dinitrogen Monoxide
Counting Atoms
Three Laws of Chemistry
There are three guiding principles in the study of chemistry.
1) The law of conservation of mass2) The law of constant composition3) The law of conservation of energy
The law that we need to know for studying chemical reactions is the law of conservation of mass.
Law of Conservation of Mass
• This law states that matter can neither be gained nor lost in a chemical reaction.
• In a chemical reaction you have to end up with the same number and type of each atom that you started with.
Calculating The Mass of a Compound
• Find the number of each atoms in a compound.
• Using the periodic table find the mass number of each type of atom in the compound.
• Multiply the mass number by the number of elements in the compound.
MgSO4
Has 1 Mg, 1 S, and 4 O
Mg = 24S = 32O = 16
Mg (24 x 1 = 24)S (32 x 1 = 32)O (16 x 4 = 64) = 120
Calculating Mass of a Compound Examples
• BaCl2 1 Ba and 2 Cl
137 + 2(35) = 207
• CaI2 1 Ca and 2 I
40 + 2(127) = 294
• C6H12O6 6 C and 12 H and 6 O
6(12) + 12(1) + 6(16) = 180
Conservation of Mass in Chemical Equations
• The total mass of the products formed in a chemical reaction must equal the total mass of the reactants.
SiCl4 + 2 H2O Si(OH)2 + 4 HCl
1.00g ? 2.20g 1.90g
2.20 + 1.90 = 4.10
4.10 – 1.00 = 3.10
3.10 is how much H2O there is in the equation
Another Conservation of Mass Example
• FeSO4 + 2 KI FeI2 + K2SO4
2.95 3.21 5.40 ?
2.95 + 3.21 = 6.16
6.16 – 5.40 = 0.76
There is 0.76 g of K2SO4
Chemical Equations
• A chemical equation gives an outline of what is happening in a chemical reaction.
• The substances on the left hand side are the reactants.
• The substances on the right hand side are the products.
Keeping Both Sides Equal
• In the top pictures, the number of atoms are not equal on both sides and that can not happen in an equation.
• In the bottom picture, the same number and types of atoms appear on both sides.
Rules for Balancing Equations
1) Adjust the numbers of each kind of atom by changing the big numbers in front of the formulas of the compounds and elements. These are called the coefficients.
2) Never change the small numbers in the formulas. These are called the subscripts and are part of the formula.
3) Use pencil because you may have to change coefficients several times
4) No need to include “1” as a coefficient.
Helpful Suggestions for Balancing Equations
• Tally up how many of each type of element there is on each side of the equation.
• Work on one thing at a time.• Look for polyatomic ions or elements that
appear only once on each side. Balance those first.
• If you have difficulty balancing an element, leave it and come back to it at the end.
• Leave H2, N2, O2, F2, Cl2, Br2, and I2 to balance at the end.
Balancing Equations Example
• Na + Cl2 NaCl
Another Balancing Equation Example
• C + O2 CO
Yet Another Balancing Equation Example
• KI + Pb(NO3)2 PbI2 + K(NO3)
Writing and Balancing Equations
• You need to have your periodic table handy.• You also need your reference sheet handy.
• You will read a sentence and make up a skeleton equation.
• And then you will balance the skeleton equation!
Two handy hints!
• If an element is by itself it has no charge» Sodium metal is just Na» Magnesium is just Mg» Gold is just Au
• If one of the following is written in the sentence by itself, it comes in a pair (diatomic)
» Hydrogen, Nitrogen, Oxygen, Fluorine, Chlorine, Bromine, Iodine and Astatine
» H2 N2 O2 F2 Cl2 Br2 I2 At2
Example 1
• Sodium and Fluorine react to form Sodium Fluoride
Example 2
• Sodium Chloride and Silver (I) Nitrate react to form Sodium Nitrate and Silver (I) Chloride
Example 3
• Aluminum metal and Copper (II) Chloride react to form Aluminum Chloride and Copper metal
Example 4
• Beryllium Oxide and Carbon Dioxide react to form Beryllium Carbonate
Example 5
• Sodium Oxide and Carbon Dioxide react to form Sodium Carbonate
Example 6
• Potassium Chlorate reacts to form Potassium Chloride and Oxygen gas (hint!)
Example 7
• Potassium oxide and water react to form potassium hydroxide
Example 8
• Chlorine gas and Sodium Bromide react to form Sodium Chloride and Bromine gas
Example 9
• Magnesium metal and Hydrogen Chloride react to form Magnesium Chloride and Water
Example 10
• Sodium Carbonate and Calcium Chloride react to form Sodium Chloride and Calcium Carbonate
Example 11
• Zinc (II) Carbonate reacts to form Zinc (II) Oxide and Carbon Dioxide
Information Gained from Chemical Reaction
• It is sometimes useful to know the state of a compound in a given chemical reaction. This information is given in the form of a subscript in parentheses after the formula.
• (s) is solid
(l) is liquid
(g) is gas
(aq) is aqueous
(dissolved in water)
(ppt) is precipitate
(solid in a liquid)
Types of Chemical Reactions
• There are five basic types of chemical reactions:– Synthesis– Decomposition– Single Replacement– Double Replacement– Combustion
Synthesis Reactions
• Synthesis reactions happen when two or more substances combine to form one compound.
A + B AB
2 Na + Cl2 2 NaCl
Al + P AlP
Decomposition Reactions
• Decomposition Reactions happen when one substance breaks down into two or more simpler substances.
• AB A + B
• CaF2 Ca + F2
• 2 Fe2O3 4 Fe + 3 O2
Single Replacement Reactions
• Single Replacement reactions happen when one element is replaced by another in a compound
• A + BC AC + B
• Zn + CuCl ZnCl + Cu
• MgO + Ca Mg + CaO
Double Replacement Reactions
• Double Replacement reactions happen when two elements in a reaction exchange places with each other.
• AB + CD AD + CB
• PbCl + KBr PbBr + KCl
• HCl+Ca(OH)2H(OH)+CaCl2
Combustion Reactions
• Combustion Reactions involve the burning (O2) of a hydrocarbon to form carbon dioxide and water.
• CXHY + O2 CO2 + H2O
• 2C2H6+7O24CO2 + 6H2O
• 2CH4 + 4O2 2CO2 + 4H2O
Acids and Bases
And neutralization reactions
Acids
• Substances that release hydrogen ions (H+) when mixed in water
• Physical Properties:– Sour tasting– Wet to the touch when in solution– Water soluble– Good conductors of electricity, therefore
electrolytes
Acids
• Chemical Properties– React with metals to produce hydrogen
gas– Corrosive– Make chemical indicators change colour– React with bases to produce a neutral
solution
Acids
• Examples:
Bases
• Substances that release hydroxide ions (OH-) when mixed in water. Also called alkaline
• Physical Properties:– Bitter tasting– Slippery to the touch when in solution– Water soluble– Good conductors of electricity, therefore
electrolytes
Bases
• Chemical Properties– Corrosive– Make chemical indicators change colour– React with acids to produce a neutral
solution
Bases
• Examples:
Chemical Indicators
• Are solutions that change colour in acids and in bases
• Can be either – natural or – synthetic
Chemical Indicators
• Litmus paper:– Base turns it Blue!– Acid turns it Red!
Universal Indicator is a mixture of chemicals that changes colour through a wide range of pH values
The pH scale• A numerical scale used to show how
acidic or basic a solution is
• pH stands for “power of hydrogen”
The pH scale• pH is a logarithmic scale which means
that every unit on the scale represents a tenfold (10X) effect on the concentration of the solution
The pH scale: Logarithmic• This means that pH 3 is 10 times more acidic than ph 4. • If the value changes by more than one number you
must multiply – ex. From pH 5 to pH 8 = 10 x 10 x 10 (3 steps = 10
multiplied by itself 3 times)
Naming Acids
• A binary acid forms when an H+ bonds with a non-metal
• HF (aq), HCl (aq), HBr (aq), HI (aq), H2S (aq), and H3P (aq) are some common binary acids
• To name them, use the following structure:– “hydro + ______ ic acid”
Naming Acids
• An oxyacid has a non-metal and an oxygen component
• H3PO4, HClO3, HIO3, H2SO4, HBrO3, H2CO3, and HNO3 are some common oxyacids
• To name them:– “_____________ ic acid”
Naming Bases
1. Name the metal
2. Name the polyatomic (i.e. hydroxide)
• Example– Mg(OH)2 – magnesium hydroxide
Neutralization Reactions• A type of double displacement reaction
• Acid + Base Water + Salt
• A salt is an ionic compound. The pH of the products is around 7 (neutral)
Example
hydrochloric acid + sodium hydroxide water + sodium chloride
Practise!!
• Try the practise questions on your worksheet!