Download Chemistry Final ACS Exam: 75 Questions with Verified Answers and more Exams Chemistry in PDF only on Docsity!

Chemistry Final ACS Exam 75 Questions with Verified

Answers

Accuracy? - CORRECT ANSWER Closeness of measurements to the TRUE VALUE of what is being measured Precision? - CORRECT ANSWER Closeness of a SET of measurements How do you calculate Percent Error? - CORRECT ANSWER I experimental-accepted I ____________________ x 100 accepted value Are zeros infront of non-zero digis significant? - CORRECT ANSWER Nope! ex: 0.0071 is only 2 sig figs Are zeros at the end of a number and to the right of the decimal significant? - CORRECT ANSWER Yep! ex: 9.100 is 4 sig figs Addition/Subtraction in regards to sig figs? - CORRECT ANSWER Round numbers to the least number of decimal places Multiplaction/Division in regards to sig figs? - CORRECT ANSWER Round answers to the least amount of sig figs

of e- equal - CORRECT ANSWER the # of p+

Atomic Mass? - CORRECT ANSWER Number of protons in the nucleus (number on the left bottom corner of the chemical symbol) Atomic Mass Number? - CORRECT ANSWER Number of protons and neutrons (number on the left upper corner of the chemical symbol) Isotope? - CORRECT ANSWER Atoms of the same element, but with different masses (different number of neutrons)

STUDY ELECTRON CONFIGURATIONS - CORRECT ANSWER STUDY ELECTRON

CONFIGURATIONS

Do columns or rows in the Periodic Table have similar patterns? - CORRECT ANSWER Columns (the "groups") have repeating patterns? Which area of the Periodic Table has greater metallicness? - CORRECT ANSWER Left and down has greater metallicness Which area of the PT has greater atomic size? - CORRECT ANSWER Left and down has a greater atomic size Which area of the PT has greater ionization energy? - CORRECT ANSWER Right side and up has greater ionization energy Which area of the PT has greater electronegativity? - CORRECT ANSWER Right side and up has greater electronegativiy, except the Noble Gases of 0 electronegativy Ionic Bonding? - CORRECT ANSWER Metal and a nonmetal. Give/take electrons Covalent bonding? - CORRECT ANSWER Nonmetal and a nonmetal. Share electrons. VSEPR Theory? - CORRECT ANSWER Valence Shell Electron Pair Repulsion aka Valence e- pairs stay as far apart as possible How do you determine polarity? - CORRECT ANSWER Use the chart that has electronegativity values, then subtract the elements in the compound from each other. Is water polar? - CORRECT ANSWER Yes! Combination Reaction? - CORRECT ANSWER A + B --> AB Decomposition Reaction? - CORRECT ANSWER AB --> A + B

Single Replacement Reaction? - CORRECT ANSWER AB + C --> AC + B Double Replacement Reaction? - CORRECT ANSWER AB + CD --> AD + CB Combustion Reaction? - CORRECT ANSWER C + H + O --> H2O + CO2 always Avogadro's Number? - CORRECT ANSWER 6.022 x 10^23 particles = 1 mole Molar Mass? - CORRECT ANSWER gram/mole Mole to Volume? - CORRECT ANSWER 1 mole = 22.4 L Empirical Formula vs Molecular Formula? - CORRECT ANSWER Molecular = the actual number of atoms in a compound Empirical = basic ratio, smallest whole numbers of atoms in a compound Percent Composition? - CORRECT ANSWER Mass element/mass compound x 100 Limiting Reactant? - CORRECT ANSWER The reactant which runs out first...meaning it limits how much product can be made ex: If there's 1 mole of NaOH and 2 moles of HCl, NaOH is the limiting reactant, because it is used up (only 1 mole) Which state of matter has the greatest Kinetic Energy? - CORRECT ANSWER Gas has the greatest KE, because the particles are far apart and moving fast What are the three types of Intermolecular Forces? - CORRECT ANSWER (1) Hydorgen Bonding (2) Dipole Attraction (3) Dispersion Forces What do you call a solid changing to a gas? - CORRECT ANSWER Sublimation What are the values for STP? - CORRECT ANSWER 0 Celcius or 273 Kelvin 1 atm = 101.3 kPa = 760 mmHg

Why is the pressure of a gas directly proportional to the number of particles? - CORRECT ANSWER P1/N1 = P2/N2....because pressure is caused by collisions of gas, and more particles means more collisions Why is the volume of a gas inversely proportional to pressure? - CORRECT ANSWER P1 x V1 = P2 x V2...because as volume increases, there is less opportunity for particles to collide Why is the pressure of a gas directly proportional to temperature? - CORRECT ANSWER P1/T1 = P2/T2....because as temperature increases, KE increases, which makes collisions happen more often and harder Why is the volume of a gas directly proportional to temperature? - CORRECT ANSWER V1/T1 = V2/T2....because as temperature increases, KE increases, and the particles spread aout PV=nRT - CORRECT ANSWER Pressure x Volume = # of moles x Gas Constant x Temperature Dalton's Law of Partial Pressure? - CORRECT ANSWER P total = P1 + P2 + P ... Graham's Law of Effusion? - CORRECT ANSWER Rate A/Rate B = Square Root of Molar Mass B/Molar Mass A If a solution is saturated, is there left over solute? - CORRECT ANSWER Yes, saturated = left over solute Unsaturated = all solute is dissolved Molarity (M)? - CORRECT ANSWER Moles Solute mole

---

Liters Solution L Making Dilutions? - CORRECT ANSWER M1V1 = M2V Percent By Mass? - CORRECT ANSWER % m/m = mass solute --------------- x 100 mass solution

molality (m)? - CORRECT ANSWER Moles Solute mole

---

kg Solvent kg Specific Heat? - CORRECT ANSWER c = q/mΔT Heat? - CORRECT ANSWER q=mcΔT Calorimeter's are used to find? - CORRECT ANSWER Specific heat capacity Endothermic? - CORRECT ANSWER Heat goes INTO system, aka q = + Exothermic? - CORRECT ANSWER Heat goes OUT of system, aka q = - How does surface area affect the rate of reaction? - CORRECT ANSWER The more surface area, the faster the reaction, because there's more room available for colisions How does concentration affect the rate of reaction? - CORRECT ANSWER More concentration = faster reaction, because with more stuff, there's more collisions How does temperature affect the rate of reaction? - CORRECT ANSWER Higher temperature = faster reaction, because more energy/speed for collisions How do catalysts affect the rate of reaction? - CORRECT ANSWER Catalysts lower the Activation Energy, which puts each collision into correct orientation, and makes the reaction "eaiser" How do you calculate Activation Energy? - CORRECT ANSWER Ea = E ac - E r (Energy of activated complex - energy of reactants) How do you calculate ΔH from a graph? - CORRECT ANSWER ΔH = E p - Er (Energy of products - energy of reactants) What are the units for Heat Capacity? - CORRECT ANSWER joules/degrees celcius

What are the untis for Specific Heat? - CORRECT ANSWER joules/grams x degrees celcius How does concentration affect equilbrium? - CORRECT ANSWER (1) If you add more products, you add more reactants (aka shift left). (2) If you add more reactants, you add more products (aka shift right). (3) If you remove products, you make more products (aka shift right) (4) If you remove reactants, you make more reactants (aka shift lef) How does temperature affect equilbrium? - CORRECT ANSWER (1) If you add more heat, you shift towards the side without heat (2) If you remove heat, you shift towards the side that's having the heat removed How does pressure affect equilbrium? - CORRECT ANSWER * only affects GASES

• always depends on number of moles...like if you decrease pressure, it shift towards the side with more moles What's the Equilbrium Constant? - CORRECT ANSWER Keq = [products]^

---

[reactants]^ Ka? and Kb? - CORRECT ANSWER KaKb = [dissociated products]

---

[acid/base reactant] Kw? - CORRECT ANSWER Kw = [H+] x [OH-] = 1 x 10 ^- Sum of Oxidation Numbers of a Neutral Compound? - CORRECT ANSWER 0! Sum of Oxidation Numbers for a Polyatomic Ion? - CORRECT ANSWER The Ionic Charge! What's ususally the oxidation number of Oxygen? - CORRECT ANSWER Usually always is -2! What's an example of a homogeneous mixture? - CORRECT ANSWER A homogenous mixture is uniform in composition, so like vinegar is homogenous

What do you use to seperate a homogeneous mexiture? - CORRECT ANSWER Chromatography.... How do you know which gas is fastest? - CORRECT ANSWER The lighter they are, the faster they are...aka add together their masses, and see which one has the smallest mass #17 yellow packet, When it show's a picture before a reaction, and want's to know what it looks like after the reaction...how do you know which one it is? - CORRECT ANSWER It will have the little one's leftover