Name: Teacher: Period: 2|P a g e 2|P a g e 3|P a g e Metric System 3|P a g e 4|P a g e 4|P a g e 5|P a g e Temperature Kelvin (K) Miscellaneous Conversions 0K = - 273C 0K = - 460F Amount of Substance Mole (mol) 1 mol = 6.022 x 1023 (Avogadro’s number) Volume @ STP 22.4 L / mol of gas Pressure Energy Pascal (Pa) Joule (J) K = C + 273 1 atm = 101.325 kPa = 760 mm Hg = 760 torr = 14.70 psi 1 calorie (cal) = 4.184 J Formulas, Measurements, and Mathematics 1. Conversion Factor: a ratio of equivalent measurements, including units, that is expressed as a fraction 2. Percent Error = │experimental value – accepted value│ x 100 accepted value 3. Temperature Conversions 4. Density (D) = mass__ volume 5. Average Atomic Mass: the weighted average mass of the naturally occurring isotopes of an element 6. Percent Composition = mass of element x 100 mass of compound 7. Mole Ratio: a conversion factor derived from the coefficients of a balanced chemical equation 8. Empirical Formula: % to Mass, Mass to Mole, Divide by Small, Multiply til Whole 9. Molecular Formula = molecular formula mass = multiplier empirical formula mass °C = K – 273 K = °C + 273 10. Percent Yield = actual yield___ x 100 theoretical yield 11. Combined Gas Law P1V1T2 = P2V2T1 12. Ideal Gas Law PV = nRT Where R = Universal Gas Constant = 0.0821 L ∙ atm/mole ∙ K OR Where n = moles 8.314 dm3 ∙ kPa/mol ∙ K 13. Dalton’s Law of Partial Pressure PTotal = P1 + P2+ P3 + … 14. Percent Water in a Hydrate = mass of water_ x 100 mass of hydrate 15. Molarity (M) = moles of solute liter of solution 16. Dilution Molality (m) = moles of solute____ kilograms of solvent M1V1 = M2V2 17. Titration MAVANA = MBVBNB 18. Heat is represented by two values: q or ΔH 19. Specific Heat (C) 20. Acids/Bases pH = -log [H+] Where 1 = initial and 2 = final ΔHsystem = - ΔHsurroundings or qsystem = -qsurroundings q = mCΔT [H+] = 10 –pH Where A = acid and B = base pOH = -log [OH-] [OH-] = 10 –pOH Where ΔT = Tfinal - Tinitial pH + pOH = 14 21. Equilibrium Constant (Keq): a ratio of the concentration of the products to the reactants where the coefficient if each substance in the balanced equation becomes an exponent for that concentration 5|P a g e 6|P a g e Keq = [products]x__ [reactants]x x is the molar coefficients from a balanced equation NUMBERS WRITTEN in SCIENTIFIC NOTATION In chemistry, we often have to deal with either very large numbers, such as 602 300 000 000 000 000 000 000 000 (the number of things in a mole), or very small numbers, such as 0.000 000 000 000 000 000 000 000 000 911 grams (the mass of an electron). Such numbers are much more conveniently expressed as some number between 1 and 10 times an exponential term. The exponential term contains an exponent which is a base. The base is usually 10. For example: 1 = 1 x 100 0.2 = .2/101 = 2 x 10-1 1 30 = 3 x 10 500 = 5 x 102 0.007 = 7/103 = 7 x 10-3 When calculating with numbers written in scientific notation using a scientific calculator, one must be careful entering the values. For example: The number 6.022 x 1023 is entered as follows: 1. Clear your calculator display 2. Enter 6.022 3. Hit the KEY marked EE, EXP 4. The display will look like this: 6.022 00 5. Enter in the exponent, 23 6. The display will look like this: 6.02 23 7. If a negative exponent is needed, then 8. Hit the key 9. The display looks like this: 6.022 -23 For adding, subtracting, multiplying, or dividing numbers in scientific notation and using a calculator, it is vital that you DO NOT ENTER “TIMES 10” for the “10x” portion of the number in scientific notation. “Times 10” means multiply by 10, and “10x” means multiply the base number by 10 as many times as indicated by the exponent “x”. Writing a number in this form is a “shorthand” method of expression. The notation 6.022 x 1023 tells us to multiply 6.023 by 10 twenty-three times. The notation 9.11 x 10-28 tells us to divide by 10 twenty-eight times. Examples of converting a scientific notation number into the expanded version. 1.23 x 102 6.78 x 10-3 Positive exponent shifts the decimal to the right Negative exponent shifts the decimal to the left. Rules for Counting Significant Figures 1. Nonzero integers. Nonzero integers always count as significant figures. 2. Zeros. There are three classes of zeros a. Leading zeros are zeros that precede all the nonzero digits. These do not count as significant figures. In the number 0.0025, the three zeros simply indicate the position of the decimal point. This number has only two significant figures. b. Captive zeros are zeros between nonzero digits. These always count as significant figures. The number1.008 has four significant figures. c. Trailing zeros are zeros at the right end of the number. They are significant only if the number contains a decimal point. The number 100 has only one significant figure, whereas the number 1.00 x 102 has three significant figures. The number one hundred written as 100. also has three significant figures. 6|P a g e 7|P a g e 3. Exact numbers. Many times calculations involve numbers that were not obtained using measuring devices but were determined by counting: 10 experiments, 3 apples, 8 molecules. Such numbers are called exact numbers. They can be assumed to have an infinite number of significant figures. RULES for SIGNIFICANT FIGURES in MATHEMATICAL OPERATIONS 1. For multiplication or division the number of significant figures in the answer is the same as the number in the least precise measurement used in the calculation. For example, consider this calculation: 4.56 x 2.4 = 6.36 (corrected) 6.4 least precise two significant figures has two significant figures allowed in answer The product should have only two significant figures, since 2.4 has two significant figures. 2. For addition or subtraction the result has the same number of decimal places as the least precise measurement in the calculation. For example, consider the sum: 12.11 18.0 limiting term has one decimal place 1.013 31.123 (corrected to) 31.1 \ one decimal place The correct result is 31.1, since 18.0 has only one decimal place. Note that for multiplication and division, significant figures are counted. For addition and subtraction, the decimal places are counted. In most calculations, you will need to round numbers to obtain the correct number of significant figures. The following rules should be applied when rounding. RULES for ROUNDING 1. In a series of calculations, carry the extra digits through to the final result, then round. 2. If the digit is to be removed a) is less than 5, the proceeding digit stays the same. For example: 1.33 rounds to 1.3 b) is equal or greater than 5, the proceeding digit is increased by 1. For example: 1.36 rounds to 1.4 Although rounding is generally straightforward, one point requires special emphasis. As an illustration, suppose that the number 4.348 needs to be rounded to two significant figures. In doing this, we look only at the first number to the right of the 3. 4.348 \ look at this ‘4’ to round number to 2 significant figures The number is rounded to 4.3 because 4 is less than 5. It’s incorrect to round sequentially. In other words, use only the first number to the right of the last significant figure. 7|P a g e 8|P a g e Aufbau Diagram 8|P a g e 9|P a g e 9|P a g e 10 | P a g e Naming Compounds Inorganic Compounds Metal ion plus non-metal ion With two ions: -ide ending Example: Na+ and Cl- = NaCl sodium chloride *notice the first name the compound doesending not change! With a that variable ion andinanother ion: -ide Example: Fe2+ and S2- = FeS iron (II) sulfide *notice that the variable ion has its charge (II) indicated With an ion and a polyatomic ion: Example: Ca2+ and (SO4)2- = Ca(SO4) calcium sulfate *the name of the polyatomic ion does not change With a variable ion and a polyatomic ion: Example: Cu2+ and (CrO4)2- = Cu(CrO4) copper (II) chromate * the variable ion has its charge (II) indicated Inorganic * the nameMOLECULAR of the polyatomiccompounds ion does not change Two non-metal ions forma a molecular compound HYDROGEN is often considered a non-metal (ex.1) These compounds use prefixes instead of roman numerals (such as mono-, di-, tri-, tetra-, etc.) Mono- is not used when the first ion in the compound is singular (ex. 3 & 4) The second member of the compound ends in –ide Example 1: H2O dihydrogen monoxide Example 2: N2O3 dinitrogen trioxide Example 3: CO2 carbon dioxide ACIDS: Monoprotic Acids (1 available H+) Hydrochloric Acid Nitric Acid Nitrous Acid Acetic Acid HCl HNO3 HNO2 HCH3COO Diprotic Acids (2 available H+) Sulfuric Acid Sulfurous Acid Carbonic Acid Hydrosulfuric Acid (hydrogen sulfide) H2SO4 H2SO3 H2CO3 H2S Tripotic Acids (3 available H+) Phosphoric Acid H3PO4 BASES: Ammonia Sodium Hydroxide Potassium Hydroxide 10 | P a g e NH3 NaOH KOH 11 | P a g e 11 | P a g e 12 | P a g e 12 | P a g e 13 | P a g e Electronegativity of Elements 13 | P a g e 14 | P a g e Activity Series List Potential Cations Lithium Potassium Rubidium Cesium Radium Barium Strontium Calcium Sodium Lanthanum Cerium Neodymium Samarium Gadolinium Magnesium Yttrium Americium Lutetium Scandium Plutonium Thorium Neptunium Beryllium Uranium Hafnium Aluminum Titanium Zirconium Manganese Vanadium Niobium Selenium Zinc Chromium Gallium Tellurium Iron Cadmium Indium Thallium Cobalt Nickel Molybdenum Tin Lead Hydrogen Copper Mercury Silver Rhodium Palladium Platinum Gold 14 | P a g e Potential Anions Flourine Chlorine Bromine Iodine The most active potential cations/anions are at the top of each list. 15 | P a g e Solubility Rules Chloride, Bromide, Iodide: Cl-, Br-, I- Negative ion (anion) Plus Positive Ion (cation) Forms a compound Which is 1. Any ion + Alkali ions (Li+, Na+, K+, Rb+, or Cs+) “ Soluble, i.e. 0.1 mol/liter 2. Any ion + Ammonium, NH4+ “ Soluble 3. Nitrate, NO3- + Any cation “ Soluble 4. Acetate, CH3COO- + Any cation except Ag+ “ Soluble 5. Chloride, Cl- or Bromide, Br- or Iodide, I- + + + Ag+, Pb2+, Hg2+, or Cu+ Any other cation “ “ Not Soluble Soluble 6. Sulfate, SO42- + + Ca2+, Sr2+, Ba2+, Ra2+, Ag+, or Pb2+ Any other cation “ “ Not soluble Soluble 7. Sulfide, S2- + + + Alkali ions or NH4+ Be2+, Mg2+, Ca2+, Sr2+, Ba2+, or Ra2+ Any other cation “ “ “ Soluble Soluble Not Soluble 8. Hydroxide, OH- + + + Alkali ions or NH4+ Sr2+, Ba2+, or Ra2+ Any other cation “ “ “ Soluble Soluble Not Soluble 9. Phosphate, PO43+ or Carbonate, CO32- or Sulfite, SO32- + + Alkali ions or NH4+ Any other cation “ “ Soluble Not Soluble 15 | P a g e 16 | P a g e 16 | P a g e 17 | P a g e 17 | P a g e 18 | P a g e 18 | P a g e 19 | P a g e 19 | P a g e