Science 10: Unit 1 - Chemistry

Science 10: Unit 1 - Chemistry Chapter 1 Lab Safety: WHMIS(Workplace Hazardous Material Information System) is a system of labels that determines the hazards of a substance.

Things you would find on a WHMIS label includes: The symbol, the chemical name, and how/where to store it Ways to get hurt: Inhalation, skin absorption, ingestion and injection Important PPE includes safety goggles, earmuffs, lab coat, gloves Some other safety protocols include tying up hair, wafting, no horseplay and no food or drink in the lab   The MSDS(Material Safety Data Sheet) is a sheet that contains more detailed information on a dangerous substance. It contains: - Boiling/melting point of the substance - Chemical properties of the substance - How to store, dispose and clean up - Health hazards of the substance (WHMIS label)  

The Atomic Theories over time: John Dalton - Billiard Ball Model - Differently sized round particles, too small to see, coined "atom" Thomson - Plum Pudding Model - Positive charged sphere with negative particles inside Ernest Rutherford - Solar System Model - Tiny positive nucleus, negative particles orbited it Neils Bohr - Bohr Model - Neutrons added mass to the nucleus, electrons orbited in different energy levels *Nowadays, the Quantum theory is learned

Atoms, Isotopes and Ions:   Atoms - Uncharged, neutral - Equal number of protons and electrons - Protons and neutrons in an atom contain the most mass, while the electrons and energy levels have the most volume - Atomic number: number of protons in the nucleus   Isotopes - Atoms of the same element with slightly different masses(number of neutrons) - Mass number = protons + neutrons (of specific isotope) - Atomic mass on the periodic table is the average of all the isotopes of an atom(that's why it's a decimal!)   Ions - Atoms want to have full energy levels(noble gases have full energy levels), so they exchange electrons and become an ion - First 3 energy levels have a capacity of 2-8-8 electrons - Unequal amount of protons and electrons - If there are more electrons, it is an anion (negatively charged). Anions are nonmetals that gain electrons to become like noble gases. When named, "ide" is added to the end (Cl = Chlorine, Cl- = Chloride) - If there are more protons, it is a cation (positively charged). Cations are metals that lose electrons to become like a noble gas. Names don't change when created *Carbon and silicon do not have ions   The Periodic Table Helps! Period number = Number of energy levels in atom] Group number = Number of valence electrons (if it's over 10, subtract 10) Number of elements in period = The maximum number of electrons in each shell (2, 8, 8, 18...)  

This is a Bohr Diagram. It represents the energy levels and amount of protons, electrons, and neutrons. However, there are more ways to represent an atom.

This is an electron dot diagram. It represents the number of valence electrons. if there are more than four, they are paired together. Anions have more than four valence electrons while cations have less than four valence electrons.

Science 10: Unit 1 - Chemistry Chapter 2 Ionic Compounds: A compound where a metal ion and a nonmetal ion exchange electrons to make their valence shells full(the metal gives an ion to the nonmetal). Eg. NaCl, MgO, CaBr(2) *Carbon, Boron, Silicon and the Noble Gases do not form ionic compounds Properties of Ionic Compounds: - All compounds are neutral (electrons balance out) - A metal and a nonmetal - Electrons are exchanged - Have no prefixes when being named - Mostly solid at room temperature(except for mercury, which is liquid) - Can be dissolved in water to make acids - Form a crystal lattice structure - All have high melting points - All conduct electricity in solution   When naming ionic compounds, add "ide" to the end of the nonmetal's name. Eg. sodium chlorIDE, magnesium oxIDE, calcium broMIDE   Molecular Compounds: A compound where two nonmetals share electrons to have one shared full valence shell.  Eg. CO2, H2O, O2  Diatomic Molecules: Some nonmetals only occur in certain molecules - H2, O2, Br2, 2, I2, N2, Cl2 "hobr fincl"  - P4, S8 " p be4 itS too l8" 

Properties of Molecular Compounds: - Two nonmetals share electrons (not ions!) - Have prefixes to state number of atoms in compound - Can be any state at room temperature - Doesn't dissolve in water well - Low melting point - Poor conductors of electricity   When naming molecular compounds, prefixes are used to clarify the number of atoms. The first atom will only have a prefix if there are more than one of them, the second atom will always have a prefix. 1 - mono 2 - di 3 - tri 4 - tetra 5 - penta 6 - hexa 7 - hepta 8 - octa 9 - nona 10 - deca Eg. carbon DIoxide, DIhydrogen MONOxide, carbon MONOxide Some complex ions can be form from several nonmetals(with hydrogen acting as a metal)Eg. CH3COO- (this is acetate, and it doesn't follow normal labelling rules)   Other Naming Rules: Some ions have multiple charges that must be labelled. We used Roman Numerals in the name to specify which charge we are using (Eg. II = 2+ charge) Eg. FeO is iron(II) oxide, PtF(4) is platinum(IV) fluoride When dealing with complex ions, don't change the end of their names.   Complex Hydrogen Compounds to Remember: NH3 - Ammonia CH4 - Methane CH3OH - Methanol H20 - Water H202 - Hydrogen peroxide C6H5OH - Ethanol C6H12O6 - Glucose C12H22O11 - Sucrose   Intermolecular vs. Intramolecular: - Intermolecular are bonds BETWEEN molecules Eg. (Covalent bonds, Ionic bonds) - Intramolecular are bonds WITHIN molecules Eg. (Dipole/Dipole, Hydrogen Bond, LDF)

Science 10: Unit 1 - Chemistry Chapter 2 Acids and Bases: Acids: A compound that when dissolved in water, creates hydrogen ions (H+) Eg. Vinegar, stomach acid, lemon juice, battery acid Have a pH (percentage of hydrogen ions) of 0 - 7  - Tastes sour - Not slippery - Corrodes metal - Red litmus indicator - Good conductor Bases: A compound that when dissolved in water, creates hydroxide ions (OH-) Eg. Baking soda, drain cleaner Have a pH (percentage of hydrogen ions) of 7 - 14 - Tastes bitter - Slippery - Blue litmus indicator - Good conductor We use an acid-base indicator to tell what pH a substance has Eg. Litmus paper (blue = base, red = acid) The pH of common substances: Battery acid - 1 Lemon juice -  Vinegar - 3 Soda - 4 Water - 7 Baking Soda - 8 Stomach acids - 9 Ammonia - 11 Bleach - 12 Identifying Acids and Bases: In acids, there is a presence of H+ on the LEFT SIDE (or right side if it's a complex ion). Also has the symbol "aq". Eg. HCl(aq), Ch3COOH(aq) In bases, there is a presence of an OH- at the end Eg. NaOH, NH4OH, Ca(OH)2 Naming Acids: If you are just calling the acid by its normal compound name, add "aqueous" to the beginning. To name an acid: Hydrogen ____ide > Hydro____ic acid Hydrogen ____ate > ____ic acid Hydrogen ____ite > ____ous acid  

Science 10: Unit 1 - Chemistry Chapter 2 Why is Water Weird? - Water has a higher melting/boiling point compared to similar substances - Water has a high specific heat capacity - Ice is less dense than liquid water (most dense at 4C) - Water has a high surface tension - Water is cohesive and adhesive - Water is neutral (has both OH- and H+)   Solubility: Solubility is the ability for one substance to dissolve into another. We use a solubility chart to organize this.

When something has low solubility, it forms a precipitate(solid). This allows you to determine the state of a compound in a reaction. ab = cd > ad(aq) + cb(s) This means that "ad" is soluble and that "cb" is not

Science 10: Unit 1 - Chemistry Chapter 3 Chemical Vs. Physical Change Chemical Change: - Something new is made - Chemical composition is affected - Energy is absorbed(endothermic) or released - A change in energy (light, sound, or electricity is released) - Odor changes - Bubbles/ precipitate forms Physical Change: - Change in state - Nothing new is made   Endothermic Vs. Exothermic Reactions: Endothermic: More energy is absorbed to break bonds than is released, so the environment LOSES energy (gets colder) Exothermic: More energy is released than the energy taken to break the bonds, so the environment GAINS energy (gets hotter)   Different Types of Reactions: Formation: Two elements combined into a compound (A + B = AB) Na + Cl > NaCl Decomposition: A compound separates into two elements (AB = A + B) MgO > Mg + O Single Replacement: An element replaces a similar element in a compound (AB + C = AC + B) Mg(s) + Cu(NO3) > Mg(NO3) + Cu Double Replacement: The negative and positive ions in a reaction (AB + CD > AC + BD) KI + Pb(NO3) > KNO3 + PbI2 Combustion: A reaction that results in the release of oxygen gas and energy in the form of light and heat (A + O2 > CO2 + H2O)    The Law of Conservation of Mass and Balancing Equations: Reactant + Reactant > Product (Reactants create products in a chemical reaction. The arrow always points to the product) The Law of Conservation of Mass states that the mass of the reactants must be equal to the mass of the product. In a closed system, no extra gas or substances can escape. In an open system, extra substances can escape. We assume chemical reactions take place in a closed system.  H2 + O2 > H2O This is a skeleton equation. While it does make sense, it doesn't take into account the Law of Conservation of Mass. To make the equation balanced, we need to have the same number of atoms on both sides of the equation. H2 + O2 > H2O H = 2 | H = 2 O = 2 | O = 1 As we can see here, there is not an equal number of oxygen atoms on either side of the equation. So, we have to multiply the number of atoms we have on either side of the equation to make it equal. 2(H2) + (O2) > 2(H2O) H = 4 (2x2) | H = 4 (2x2) O = 2 | O = 2 (2x1) We indicate what number we multiplied by with a larger number in front of the chemicals, called a subscript. Sometimes it can take multiple steps to balance an equation. In combustion equations, you have to go in this order (Carbon > Hydrogen > Oxygen) to balance the equation. For example: CO2 + H2O > C6H12O6 + O2 This is the chemical formula for photosynthesis. 6(CO2) + 6(H2O) > C6H12O6 + 6(O2) C = 6 (6x1) | C = 6 H = 12 (6x2) | H = 12 O = 18 (6x2) + (6x1) | O = 18 (6x2) + 6 While it was a little complicated, I managed to get it done! Now, how do we determine what state each molecule is in? We look at the solubility table! If you look below, you can tell which elements are soluble in an ion. If something is soluble, it will be whatever state it is at room temperature. If it is not soluble, it will be solid. In our case, C6H12O6 is solid because it is sugar.     

Molar Mass: A mole of a substance is 6.022 x 10(23) atoms of that substance. This is also known as Avagadro's number. Molar mass refers to the amount of mass(g) in a mole of a substance.  You use the equation n = m/M to solve for molar mass. n = amount of mols m = mass (g) M = molar mass (g/mol) The atomic molar mass is displayed on the periodic table, representing the molar mass of 1 mol of that substance. So a mol of carbon is 12.01 grams. Or 16 grams of oxygen is equal to a mol of oxygen.  Eg. So to solve for 7.5 mol of H2O: 2 atoms of hydrogen x 1.01 (g/mol) mol of hydrogen + 1 atom of oxygen x 16.00 (g/mol) = 18.02 g 18.02 g is for 1 mol of water, so to calculate 7.5 mol of water: 7.50 of mol of water x 18.02 g/mol (1 mol of water) = 1.35 x 10(2) g So the mass of 7.5 mol of water is equal to 1.35 x 10(2) grams.