SCH3U Exam Review Flashcards
Precision vs Accuracy
Precision: How close something is to the other shots, tries etc.
Accuracy: How close something is to the target.
Determining the amount of sig-digs
Significant digits are:
- Non-zeros Ex, 1-9
- Zeros between two non-zeros Ex, 109
- Zeros after a decimal place Ex, 32.0
Significant digits are NOT:
- Zeros before any other non-zero Ex, 0.000042
- Zeros ending a number without a decimal Ex, 95300
*Least amount of sig-digs is always used in answers
5 Clues a Chemical Reaction has taken place
- Colour change
- Odour change
- Bubbles
- Precipitate
- Heat or light is produced
Particle Theory
All matter consists of many, very small particles which are in a continual state of motion
Metals and Non-Metals on the Periodic Table
Metals:
- left side and central part of periodic table
- solids
- lustrous
- good conductors
- high melting points
- many are flexible, ductile and malleable
Non-Metals:
- right side of periodic table
- mostly gasses and powdery solids
- not shiny, ductile or malleable
- low melting points
- only liquid is bromine
Chemical families (Groups) on the Periodic Table
Vertical Columns:
Alkali Metals - Far left Column 1 shiny, soft, highly reactive with water and air
Alkali Earth Metals - Column 2 shiny and will burn bright colours
Noble Gasses - Far right Column 8 colourless, odourless, tasteless and very stable
Halogens - Column 7 very reactive, many are poisonous
Trends in the Periodic Table:
Orbits and Valence Electrons
Orbits: Elements have the same number of orbits as the number of the period they are in.
Valence Electrons: Elements have the same number of valence electrons as the number of the group they are in.
Trends in the Periodic Table:
Atomic Radius, Ionization Energy, Electron Affinity and Electronegativity
Atomic Radius: Increases down and to the left
Ionization Energy: Increases up and to the right
Electron Affinity: Increases up and to the right
Electronegativity: Increases up and to the right
What is an isotope?
An isotope is an atom of the same element that has different number of neutrons
Ex, /Users/CaitSforza/Desktop/Screen Shot 2016-01-25 at 10.43.15 AM.png
What is the difference between an ionic compound, polar molecular compound and non-polar molecular compound?
Ionic compound: Metal and a Non-Metal 1.67-3.3EN
Polar molecular compound: 2 Non-Metals 0.5-1.67EN
Non-Polar molecular compound: 2 Non-Metals 0-0.5EN
To find/predict EN for a compound take EN of each element and subtract
*EN=Electronegativity
Naming Compounds:
Ionic Compounds:
Molecular Compounds:
Acids:
Binary Acid:
Ionic Compounds: Non-metals change ending to -ide
Ex, Silver Iodide
Molecular Compounds: Add correct prefix for number of atoms for each element
Ex, Dinitrogen Monoxide
Acids: Ending changes from -ate to -ic or -ite to -ous
Ex, Sulphuric Acid or Nitrous Acid
Binary Acid: Add prefix hydro- and suffix -ic
Ex, Hydrochloric Acid
*Include bracketed numbers for Cu, Fe, Pb and Sn
Ex, Copper(II)
Assigning states to all reactants and products in a chemical equation
Metals: Solids (Except Mercury is liquid)
Non-Metals: Gasses or powdery solids (Except Bromine is liquid)
Metalloids: Mostly Solids
Predicting products between a metal oxide and water and a non-metal oxide and water
A metal oxide and a water always create a base
A non-metal oxide and water always create an acid
Predicting products for the decomposition of binary compounds, metal carbonates, metal nitrates and metal hydroxides
Binary Compound: Breaks down into elements
Metal Carbonates: Break down into a metal oxide and carbon dioxide gas
Metal Nitrates: Break down into a metal nitrite and oxygen gas
Metal Hydroxides: Break down into a metal oxide and water
Identify complete and incomplete combustion reactions and predict products for each
Complete Combustion: Sufficient oxygen is present (Blue flame)
Hydrocarbon + Oxygen = Carbon Dioxide + Water
Incomplete Combustion: Insufficient oxygen is present (Yellow flame)
Hydrocarbon + Oxygen = Carbon Dioxide + Water + Carbon Monoxide + Carbon
Identify a neutralization reaction and predict the products or reactants of a neutralization reaction.
Acid + Base = Ionic Salt + Water (Double Displacement)
Predict the products of a double displacement reaction that forms water or a gas (carbon dioxide or ammonia)
Forms a Water: Neutralization (Acid + Base = Ionic Salt + Water)
What is a mole? Why is it used by chemists?
A mole is the base unit that is used to measure the amount of a substance. Chemists use it because atoms are too small too count and see and they work with large quantities of them.
Avogadro’s number
6.02×10^(23) Atoms, Molecules or Formula Units (f.u.)
The difference between atoms, formula units and molecules when using avogadro’s number
Atoms (used with a singular element) Ex, Fe(s)
Molecules (used with non-metals) Ex, H2O(l)
Formula Units (used with metal+non-metal) Ex, NaCl(s)
Calculating the percent composition of a substance using formula or from mass data
Unknown Formula (Mass Data): total mass of element in compound/total mass of compound x100
With Formula:
M of element in compound/M of compound x100
Finding the empirical formula of a substance from the percent composition or from mass data
Shows the smallest whole number ratio
- Assume 100g
- Find # of mol (Divide by M)
- Find ratio (Divide by smallest mol #)
Finding the molecular formula of a substance from percent composition or from mass data
Shows the number of atoms
molecular M given number/Empirical M=# you multiply the empirical ratio by
Determing the amount of excess reactant left over when a reaction is complete
excess moles = initial moles - moles used
*moles used = LR mole ratio to XS moles
Unsaturated vs saturated vs supersaturated solutions
Unsaturated: A solution that could dissolve more solute
Saturated: A solution that could not dissolve more solute
Supersaturated: A solution that has more solute than it can dissolve
Factors that affect the rate of dissolving and explanations at the molecular level
- Temperature Increases = Rate of Dissolving Increases because particles are moving faster and colliding more often
- Agitation/mixing Increases = Rate of Dissolving Increases because particles are being forces to come in contact with the undissolved particles at a higher rate
- Particle Size Decreases = Rate of Dissolving Increases because it causes the surface are to increase creating more exposure to the solvent
Types of intermolecular forces and their role in solubility of substances
Dipole-Dipole Forces: Intermolecular attraction between two polar molecules
Ion-Dipole Bonds: Intermolecular attraction between ions and polar molecules. Very weak making solubility easy
Hydrogen Bonds: Intermolecular attraction between hydrogen atoms and very electronegative atoms (H-O, H-S, H-N, H-F) Very strong bond, solubility is difficult/impossible
Finding the molar concentration of solutions and ions
C=n/V
Preparing solutions and dilutions-calculations
C1V1=C2V2, C=n/V
Writing ionic equations and net ionic equations
Ionic Equation: Each element set individually with its charge, state and its coefficient (solids cannot separate)
Net Ionic Equation: Only the elements that form a reaction in the equation (The precipitate)
*make sure precipitate will form before writing out equation
Acid properties and examples
Sour, conductive, corrodes tissues and metals, creates hydrogen gas, turns litmus paper red, colourless in phenolphthalein, pH of 0-7
The pH scale and acid-base colour indicators
0-7: Acid (red)
7: Neutral
7-14: Base (blue)
Properties of strong acids vs weak acids at molecular level and examples
Strong Acids: HBr - Hydrobromic Acid HCl - Hydrochloric Acid HI - Hydroiodic Acid HNO - Nitric Acid H2SO4 - Sulfuric Acid
Strong Bases:
Any metal + OH (except Beryllium)
Determining if an acid or base is strong or weak
Acid:
- High concentration of ions
- Completely ionizes in water
Base:
-Based of the degree of the dissociation in water
States of matter and predicting the state of a substance based on the type of intermolecular forces present
Solid: Strong forces between particles
Liquid: Weak forces between particles
Gas: Very Weak forces between particles
Properties of Solids, Liquids and Gases
Solid: Fixed volume, fixed shape, strong forces between particles, incompressible, vibrational motion of molecules
Liquid: Fixed volume, variable shape, weak forces between particles, incompressible, vibrational, rotational and translational motion of molecules
Gas: Variable volume, variable shape, very weak forces between particles, compressible, vibrational, rotational and translational motion of molecules
Physical properties of Gases
- Gasses are compressible
- Gasses expand as temperature increases
- Gasses have very low viscosity
- Gasses have very low densities
- Gases are miscible (able to mix completely with each other)
Ideal Gas
No volume and no attractive forces between particles
Kinetic Molecular Theory
- Gas particles are in constant, random motion
- Gas particles don’t create forces between one another
- Individual gas particles have mass but do not take up space
- Gas particles only interact with one another and with the walls of the container when they collide
- The higher the temperature the higher the kinetic energy
Pressure and Boyles Law calculations
Pressure conversions:
Pressure given x Unit you want/unit you’re in
Ex, 750mmHg x 1atm/760mmHg
Boyle’s Law: P1V1=P2V2
Kelvin Temperature scale and calculations with Charles and Gay-Lussacs Laws
Kelvin temperature scale: Designed so 0K is when a substance posses no kinetic energy. 0 degrees Celsius = 273K
Combined gas law calculations
P1V1/T1=P2V2/T2
Ideal gas law calculations
PV=nRT
*R=8.314
Acid definition
A substance that ionizes water to produce one or more hydrogen ions
Solution
A homogeneous (uniform) mixture of two or more substances
Solvent
The base substance that has other substances dissolved in it
Solute
The substance that is dissolving into the solvent
Aqueous Solution
A solution that contains water (aq)
Predicting the nature of a bond based on the electronegativity difference of bonding atoms.
Completely Ionic Bond: 3.3EN Mostly Ionic Bond: 1.7-3.3EN Polar Covalent Bond: 0.5-1.7EN Mostly Covalent Bond: 0-0.5EN Completely Covalent Bond: 0EN
S.T.P.
273K 101.3kPa
