CHEM Final EXAM PDF

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Notes!!!: Review Unit 4 Run through all the practice problems So that they boy Swapp can’t hit us with SHIIIITTTTTT Formula memorizing: We have to make a sheet based on formulas we used in the practice problems Definitions: Have a jist of all definitions, focus on the ones from previous tests since there is a greater chance those will reoccur

UNIT 1:(Lecture 1-5) ● ●

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Chemistry: ○ The study of the composition, properties, and interactions of matter Domains: ○ Macroscopic Domain: ■ the point of view/domain in which you can see with your naked eye (like in everyday life) ● Ex- Fire burning ○ Microscopic Domain: ■ the point of view/domain in which you cannot see with a naked eye ■ A lot is “imaginary” ● Ex - atoms/bacteria ○ Symbolic Domain: ■ The point of view/domain where symbols are used to describe a certain concept/thing ● Ex- Hg = Mercury Molecule: ○ Two or more atoms of elements trading electrons to combine and form one single unit ■ Ex- H + 02 = H2 O Compound: ○ Two more more atoms of an elements sharing electrons ○ Mixing and Combining ■ Ex- CsCl Homogeneous Mixture: ○ When matter does not have the same properties, or composition, it is classified as a mixture, and when a mixture is uniform throughout, it is a homogeneous mixture ■ Ex- Air/ Sports drink Heterogeneous Mixture: ○ When matter does not have the same properties, or composition, it is classified as a mixture, and when a mixture is not uniform throughout, it is heterogenous ■ Ex- Italian Dressing

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Extensive Properties: ○ Properties that are based on the amount of matter present (Quantitative) ■ Ex- Heat/ Length/ Mass/ Volume Intensive Properties: ○ Properties that are not based on the amount of mass present (Qualitative) ■ Ex- Color/ Temperature/ Density Common Unit Prefix Chart: ○ Femtof 10-15 ○ Picop 10-12 ○ Nanon 10-9 μ 10-6 ○ Micro○ Millim 10-3 ○ Centic 10-2 ○ Decid 10-1 ○ Kilok 103 ○ MegaM 106 ○ GigaG 109 ○ TeraT 1012 SI Unit Chart: ○ Length: ○ Mass: ○ Temperature: ○ Time: ○ Electric Current: ○ Amount of Substance:

meters (m) kilograms (kg) kelvin (K) second (s) ampere (A) candela (cd)

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Temperature Conversions: ○ T(℃) = K -273.15 ○ T(K) = ℃ + 271.15 ○ T(℉) = (9/5)(℃ + 32) ○ T(℃) = (5/9)(℉ - 32)

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Temperature Rules: ○ Celsius (℃)■ Freezing: O ℃ ■ Boiling: 100 ℃ ○ Farhenheit (℉)■ Freezing: 32 ℉ ■ Boiling: 212 ℉ ○ Kelvin (K)■ Freezing: 0 K (absolute zero- the coldest temperature possible/it is hypothetical)

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■ Boiling: 310 K Physical Properties: ○ Density, color, hardness, melting and boiling point, and electric conductivity Chemical Properties: ○ Flammability, toxicity, acidity, reactivity, heat, combustion, and acidity Precision V. Accuracy: ○ Precision: ■ Refers to the closeness of two or more measurements to each other ○ Accuracy: ■ Refers to the closeness of a measured value to a standard or known

value. ●

Density: ○ The ratio of the mass of a sample of the substance to its volume: ○

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Density =

mass (kg ) volume (m3 )

(kg/ m3 )

Degree of Uncertainty: ○ “Exact”: is the result of a counting measurement ■ Ex: 1 foot is exactly 12 inches ■ 1 inch is exactly 2.54 cm ○ “Uncertain”: quantities derived from measurements other than counting are uncertain to varying extents Significant figures: ○ Addition / Subtraction: ■ to the least # of decimal place ○ Multiplication / Division: ■ Round to the least # of sig figs Speed: distance (m) ○ Speed = time (s) Atomic Mass; ○ Number of protons and neutrons in an atom Atomic #: ○ Number of protons in the nucleus of the atom

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Isotopes: ○ Atoms of the same element with different charges/ different number of neutrons in the nucleus ○ THEY HAVE A CHARGE! ○ Neutrons: ■ Elements that differ in mass because of the different number of neutrons ■ Elements that are chemically identical to each other due to the same number of protons in the nucleus Isomers: ○ Compounds that have the same chemical formula BUT have different molecular structures ■ Structural Isomers: Compounds in which the molecules differ in how the atoms are connected ● Ex■ Spatial Isomers: relative orientations of the atoms can be different ● ExPeriodic Law: ○ The properties of the elements are periodic functions of their atomic number ○ A modern periodic table arranges the elements in increasing order of their atomic numbers and groups atoms with similar properties in the same vertical column ○ Elements of the periodic table are organized by according to their properties Periodic Table: ○ Periods/Series: 7 horizontal rows ○ Groups: Vertical columns (labeled 1-8) Classification of Elements: ○ Metals: ■ Shiny, ductile, good conductors of heat and electricity ○ Non-metals: ■ Dull, poor conductors of heat and electricity

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Metalloids: ■ Moderate conductors of heat and electricity ■ Properties of both metals and nonmetals Ionic Compounds: ○ (metal + non-metal) ○ Contain Ions ○ Create Ionic bonds ○ The two opposite charges attract each other Molecular/Covalent Compounds: ○ Molecules that all have the same make up, have similar abilities to attract electrons Dalton’s Atomic Theory: ○ 1) All matter is composed of atoms ○ 2) An element consists of only 1 type of atom (same for all atoms of the element)/ atoms are unique to the specific element (atomic mass) ○ 3) Atoms of one element differ in properties from atoms of all other elements ○ 4) Compounds are atoms from two or more elements combined ○ 5) Matter cannot be created nor destroyed (Law of Conservation of Matter) Empirical Formula: ○ Oxyacid Naming: ○ These compounds contain H, O, and one other element ■ To name them: ● Omit “hydrogen: ● Start w root name of anion ● Ate → “ic” or ite → “ous” ● Add “acid” ○ Table of common Acid names: Formula

Anion Name

Acid Name

HC2H3O2

acetate

Acetic acid

HNO3

nitrate

Nitric acid

HNO2

nitrite

Nitrous acid

HClO4

perchlorate

Perchloric acid

H2SO4

sulfate

Sulfuric acid

H2SO3

sulfite

Sulfurous acid

H3PO4

phosphate

Phosphoric acid

QUESTIONS ON EXAM 1: ● 1. How many types of domains are there? Explain each with one example. ○ Macroscopic: ○ Microscopic: ○ Symbolic: ● 2. Define the terms with one example of each. ○ i) Molecule: ○ ii) Compound: ○ iii) Homogeneous Mixture: ○ iv) Heterogeneous Mixture: ○ v) Extensive Property: ○ vi) Intensive Property: ● 3. Give the name and symbol of the prefixes used with SI units to indicate multiplication by the following exact quantities. ○ a) 103 : ■ kilo- (K) ○ b) 10-3  : ■ milli- (m) ○ c) 0.000001 : ■ 10-6 = micro- (μ) ● 4. Indicate whether each of the following can be determined exactly or must be measured with some degree of uncertainty (answer either “exact” or “uncertain”): ○ a) The number of eggs in a basket: ■ Exact ○ b) The mass of a dozen eggs: ■ Uncretian ○ c) The number of gallons of gasoline necessary to fill an automobile gas tank: ● 5. ACCURACY V. PRECISION PROBLEM ● 6. Complete the following conversions between SI units: ○ a) 612 g = _______________ mg ■

612 g x

(10)3 1g

= 612.000 mg =( 6.12 x10-2  mg)

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b) 8.160 m = _____________ cm

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■ 8.160 m x 101 = 816.0 cm c) 3773 μg = ______________ g

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■ 3773 μg x 101 = 3.779 x 103 d) 781 mL = _______________ L

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781 mL x

(10 ) 1 kg

e) 4.18 kg = ________________ g 3

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= .781 L =(7.81 x10-1  )

4.18 kg x

(10 ) = 1

0.027 g = (2.7 x 10-1  g)

7. Calculate these: ○ a) What is the mass of 125 mL gaseous chlorine, density = 3.6 g/L

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○ b) What is the volume of 39.657 g bromine, density = 2.928 g/cm3 8. The label on a pressurized can of spray disinfectant warns against heating the can above 130 ℉. What are the corresponding temperatures on the Celsius and kelvin temperature scales? 9. Give the number of protons, electrons, and neutrons in neutral atoms of each of the following isotopes: ○ a) ○ b) ○ c) 10. Write the molecular and empirical formulas of the following compounds: 11. Using the periodic table, classify each of the following elements as a mental or a nonmetal, and then further classify each as a main- group (representative) element, transition metal, or inner transition metals: ○ a) uranium: ○ b) bromine: ○ c) strontium: ○ d) neon: 12. Write a symbol for each of the following neutral isotopes. Include the atomic number and mass number for each. ○ a) the alkali metal with 11 protons and a mass number of 23 ○ b) the noble gas element with and 75 neutrons in its nucleus and 54 electrons in the neutral atom 13. For each of the following compounds, state whether it is ionic or covalent. If it is ionic, write the symbols for the ions involved: ○ a) NF3 ○ b) BaO ○ c) (NH4)2CO3 14. Name the following compounds: ○ CsCl ○ BaO ○ K2S

UNIT 2:(Lecture 1-14) ● Molarity: moles of solute per Liter of solution Solute ○ Molarity = ML olSolution ●

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Solute and solvent: ○ Solute: the part of the solution that is dissolved into the solvent ■ Ex: the sweet tea flavoring in sweet tea ○ Solvent: the part of the solution in which the solute dissolves in ■ Ex: the water in sweet tea Quantitative Analysis: The determination of the amount or concentration of a substance in a sample. ○ Titrant → known concentration

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○ Analyte → unknown concentration Neutralization reaction: an acid base reaction where an acid and a base are reactants and water and salt are formed. ○ Ex: HCl + NaOH → NaCl +H2O Acid: a substance that dissolves in water to yield (H3O^+) hydronium ions Bases: a substance dissolved in water to yield OH^- (hydroxide ions). Completely dissociate in water Strong Acids/ Bases: A  cids and bases that are completely ionized when dissolved in water are strong acids or bases ○ Strong acid: HCl, HBr, H2SO4, HNO3 ○ Strong base: NaOH, KOH A typical barometric pressure is 615 mm Hg. What is this pressure in atmospheres and kilopascals? ○ 1 atm= 760 mmHg ○ 101.35 kPa= 760 mmHg Limiting reactant: The reactant yielding the lesser amount of product is the limiting reagent ○ What is the limiting reactant in a reaction that produces sodium chloride from 8g of sodium and 8g of diatomic chlorine? ■ 2Na + Cl2 ---> 2NaCl A student isolated 25 g of a compound following procedure that would theoretically yield 81g. What was her percent yield? Actual Y ield ) x 100 ○ % Yield = ( T heoretical Y ield

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ass Solute Percent by mass: ( MMass ) x 100 Solution 6 M ass Solute Ppm = ( M ass Solution ) x 10 ppm

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Solute ppb= ( MMassassSolution ) x 109 ppb Atmospheric pressure (p=n p g)

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Show the calculations supporting the claim that atmospheric pressure near sea level corresponds to the pressure exerted by a column of mercury that is about 760mm high. (The density of mercury is 13.6 g/cm3 ) (g=9.81 m/s2 ) ■ *Review this problem bc there are a lot of conversions within problem. Density: ○ Calculate the density of aluminum if 27.6 cm3 has a mass of 74.6 g. ass ■ D=( V M ) olume Ion pairs: ○ For each of the following pairs of ions, write the symbol for the formula of the compound they will form: ■ Ca2+, S-2  = CaS ● Bring charges down, if they are the same # they cancel ■ Al3+, Br - = AlBr3 Molecular v empirical formulas: ○ Molecular: use common factors to simplify

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■ Ex: H4 C6 turns into H2 C3 ○ Empirical: as is, non-simplified formula Balancing equations: ○ Do practice questions from tests, and from ppts The principal component of mothballs is naphthalene, a compound with a molecular mass of about 130 amu, containing only carbon and hydrogen. A 3.000-mg sample of naphthalene burns to give 10.3 mg of CO2 ○ Determine empirical and molecular formulas Determining empirical formula: ○ 1) Turn grams into moles ○ 2) Divide by the smallest # ○ 3) (if they aren't whole numbers) Multiply these #s to get integers only ○ 4) Determine empirical weight (EW) and divide it by the molecular weight (MW), this number is n. Determining empirical formula based on percentages ○ 1) Change the percentages to grams (literally just drop the % sign, and add a “g”) ○ 2) Then, convert grams to moles ○ 3) Divide by the smallest #, get whole numbers ○ 4) This is your empirical formula. Determining molecular formula ○ Take your empirical formula, get the molecular mass and and put it over the empirical formula mass ○ https://www.youtube.com/watch?v=J_MtVs0aBdU ■ Watch: Calculating molecular formula from empirical Oxidation numbers: ○ Examples: ■ Li= +1 ■ O= -2 ■ H= +1 ■ N=+5 ■ O= -2 Convert 4.6 grams of potassium into moles ○ Multiply the # of grams by 1 mol over the molecular weight (using periodic table) so that the grams cancel, and you are left with moles of K. If .850 L of a 5.00M solution of copper nitrate, is diluted to a volume of 1.80 L by the addition of water, what is the molarity of the diluted solution? ○ Dilution formula: ■ C1V1=C2V2 Dilution: ○ preparing less concentrated solution from a more concentrated solution Precipitate: ○ a solid that forms after a reaction takes place Pressure:

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Pressure =

F orce Area

Force: ○ Force = mass x acceleration ● Oxidation reduction: ○ Oxidation (reducing agent): Gaining oxidation → losing electrons ○ Reducing (oxidizing agent): Losing oxidation # → gaining electrons ■ Example: 2Na +Cl2 → 2NaCl ● Oxidation #s: ○ Na: 0 → +1 ■ Oxidized, reducing agent ○ Cl: 0 → -1 ■ Reduced, oxidizing agent ● Combustion: ○ Organic molecule containing C, H, O ■ Organic molecule + heat (O2) → carbon dioxide + water Unit #2 Questions 1. Define the terms with one example of each: a. Molarity b. Solvent and Solution c. Neutralization reaction d. Strong acid strong base 2. A typical barometric pressure in Denver Colorado is 615 mmHg. What is the pressure in atmospheres and kilopascals? 3. What is the limiting reactant in a reaction that produces sodium chloride from 8 g of sodium and 8 g of diatomic chlorine? a. 2Na + Cl2 → 2NaCl 4. A student isolated 25 g of a compound following a procedure that would theoretically yield 81 g. What is the percent yield. 5. Show the calculation supporting the claim that atmospheric pressure near sea level corresponds to the pressure exerted by a column of mercury that is about 760mm high. Density of mercury = 13.6 g/cm^3 (g=9.81 m/s^2) 6. Calculate the density of aluminum if 27.6 cm^3 has a mass of 74.6 g. 7. For each of the following pairs of ions, write the symbol for the formula of the compound they will form: a. Ca2+ and S2b. Al+3 and Br 8. Write the molecular and empirical formulas for the following compounds a. Carbon Dioxide b. Acetelyn 9. Balance the following equations a. PCl5(s) + H2O (l) → POCl3 (l) + HCl (aq) b. H2 (g) + I2 (s) → HI (s)

10. The principal component of mothballs is naphthalene, a compound with a molecular mass of about 130 amu, containing only carbon and hydrogen. A 3.000-mg sample of naphthalene burns to give 10.3 mg of CO2 . a. Determine its empirical and molecular formulas 11. CO(NH_2)_2 is manufactured on a large scale for use in producing ura-formaldehyde plastics and as a fertilizer. What is the maximum mass of urea that can be manufactured from CO2 produced by combustion of 1.00 x 10^3 kg of carbon followed by the reaction? a. CO2 (g) +2NH3(g) → CO(NH2)2 (s) + H2O (l) 12. Assign oxidation numbers a. Li2O b. HNO3 13. According to nutritional guidelines from the US department of Agriculture, the estimated average requirement for dietary potassium is 4.7. What is the estimated average requirement of potassium in moles? 14. If 0.850 L of a 5.00-M solution of Cu(NO3)2 is diluted to a volume of 1.80 L by the addition of water, what is the molarity of the diluted solution? Unit #3 Lectures (1-22) ● Pressure: ○ force exerted on a given area ○ P=force/ Area ■ Measured in Pascal or atm ● Hydrostatic pressure: ○ the pressure exerted by a fluid due to gravity ○ p=hpg ■ P: pressure ■ H: height ■ p(fancy): density ■ G: acceleration ● Measuring pressure of combined gas: the force of the gas in the lask is measured relative to the foce of the atmosphere ○ Close end: Pgas=hpg ○ Open end: Pgas=Patm +/- hpg ● Variables: ○

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Pressure

Atm, torr, mmHg

Temperature

K (Celsius+273)

Volume

mL or L

Amount

Mole, g/MM

Atmontons or Gay Lussac’s: Pressure of given amount of gas is directly proportional to its temperature

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○ P1/T1=P2/T2 Charles Law: Volume of a given amount of gas is directly proportional to its temperature ○ V1/T2=V2/T2 Boyle’s Law: volume of a given amount of has held at a constant temperature is inversely proportional to the pressure under which is measured ○ P1V1=P2V2 Avogadro’s Law: the volume of gas is directly proportional to its amount at a constant temperature and pressure ○ V1/N1=V2/N2 ○ n= number of moles PV=nRT ○ R= .082057 L x atm/mol x K Combined gas law: if the number of moles of an ideal gas are kept constant under two different sets of conditions ○ P1V1/T1=P2V2/T2 Dalton's Law (Pressure of mixture of gases): each individual mixture exerts the same pressure that it would exert if its present alone in the container Partial pressure: pressure exerted by each individual gas in a mixture Total pressure: equal to the sum of the partial pressures of the component ○ Pi=Xi Pt ○ Mole fraction: Xi=n1/nT ■ X= number of moles of a component of a solution divided the total # of moles Vapor pressure of water: the pressure exerted by water vapor in equilibrium with liquid in a closed container Diffusion: process by which molecules disperse in space in response to difference in concentration ○ Rate of diffusion = amount of gas/ unit of time Graham’s law of effusion: the rate of effusion of a goal is inversely proportional to the square root of the mass of its particles ○ Input formula Kinetic Molecular Theory: simple microscopic model that effectively explains the gas law described on 5 rules: ○ 1) Gases are molecules in continuous motion and only move when they collide ○ 2) Molecules are small compared to distance between them ○ 3) Pressure exerted by a gas results from collisions between molecules and wall ○ 4) Gas molecules exert attractive or repulsive forces, collisions do not involve a loss of energy ○ 5) Average KE proportional to temperature of gas ■ KE(avg)=½ (mu^2rms) Maxwell Boltzmann Distribution Theory: molecular speed distribution that depicts the relative number molecules in a bulk sample of gas the possess a given speed ○ Input formula:

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■ Square root is equivalent to the velocity Effusion: depends directly on the average speed of...