CHM2045 Study Union Final Review Fall 2015

Transcription

1 CHM2045 Study Union Final Review Fall 2015 Chapter One 1. Classify each substance as a pure substance or a mixture. If it is a pure substance, classify it as an element or a compound. If it is a mixture, classify it was homogeneous or heterogeneous. 1. Gold 2. Vegetable soup 3. Carbon Dioxide 4. Kool-Aid 2. Convert 331 K to degrees F. 3. Calculate each to the correct number of significant figures. 1. (221.5 x 32.4) + 12 = 2. ( x )/ 12.7 = = 4. Classify each property as physical or chemical. 1. the tendency of ethyl alcohol to burn 2. the shine of silver 3. the smell of paint 4. the density of water 5. Based on the diagram, classify each as a physical or chemical change. Important Things from Chapter One D=M/V 1 ml=1cm 3

2 Rules for Significant Figures: 1. In multiplication and division, the result has the same amount of sig figs as the factor with the fewest sig figs. 2. In addition and subtraction, the result has the same number of places after the decimal as the quantity with the fewest spaces after the decimal. 3. ROUND ONLY THE FINAL ANSWER

3 Chapter Two 1. A hydrogen filled balloon was ignited and 3.70 g of hydrogen reacted with 17.3 g of oxygen. How many moles of water vapor was formed assuming it was the only product? How many grams? 2. Determine the number of protons, neutrons, and electrons in each of the following isotopes. 1. K Ra N Br Calculate the mass in g of each sample x Manganese atoms moles of Carbon Dioxide 4. Copper has two naturally occurring isotopes: Cu-63 with a mass of amu and a natural abundance of 69.17%, and Cu-65 with a mass of amu and a natural abundance of 30.83%. Calculate the atomic mass of Copper. (p.67) 5. Determine the number of atoms in 1.85 ml of mercury assuming it has a density of 13.5 g/ml. Important Things from Chapter Two Chapter Three

4 1. Calculate the mass percent of of carbon in each of the following compounds. 1. C 2 H 5 Cl 2. C 2 H 6 2. Name each of the following. 1. CF 4 2. Li 3 (PO 4 ) 3. H 2 CO 3 4. Pb(SO 4 ) 3. Propose a formula for each of the following. 1. Copper (II) Fluoride 2. Boron Trichloride 3. Sulfurous Acid 4. Aluminum Oxide 4. Balance the following reactions. 1. AlBr 3 + K 2 SO 4 > KBr + Al 2 (SO 4 ) 3 2. CF 4 + Br 2 > CBr 4 + F 2 3. Na 3 PO 4 + KOH > NaOH + K 3 PO4 5. The elemental mass percent composition of Vitamin C is 40.92% C, 4.58% H, and 54.50% O. Determine the empirical formula. Important Things from Chapter Three KNOW THE POLYATOMIC IONS

5 Chapter Four 1. Starting with 86.3 g NO and 25.6 g H 2, find the theoretical yield of ammonia in grams. 2NO + 5H 2 > 2NH 3 + 2H 2 O 2. If you dissolve 35.5 g of LiBr in enough water to make 2.25 L of solution, what is the molarity of the solution? 3. Write a complete ionic and net ionic equations for the following reaction. 2KOH (aq) + H 2 SO 4 (aq) > 2H 2 O + K 2 SO 4 4. Identify the oxidizing agent and reducing agent in the following reaction CO 2 + H 2 > CO + H 2 O 5. Write a balanced equation for the combustion of liquid butanol (C 4 H 9 OH)

6 Important Things from Chapter Four KNOW YOUR REACTIONS -Combustion: Oxygen in reactants, water and carbon dioxide as products -Redox: Change in oxidation states -Precipitation: yields a solid from two aqueous reactants -Acid/Base (Neutralization): Acid + Base yields water and a salt -Gas Evolution KNOW YOUR SOLUBILITY RULES

7 Chapter Five 1. Calculate the density of hydrogen gas at 150 degrees Celsius and a pressure of 725 mmhg. 2. A 1.0 L mixture of He, Ar, and Ne has a total pressure of 654 mmhg at 298 K. If the partial pressure of He is 378 mmhg and the partial pressure of Ne is 112 mmhg, what is the partial pressure of Ar? 3. Lithium reacts with nitrogen gas in the following reaction, 6Li + N 2 > 2Li 3 N What mass of lithium reacts completely with 58.5 ml of N2 gas at STP? 4. What is the pressure in a 15.0 L cylinder filled with 27.2 g of oxygen gas at a temperature of 302 K? 5. A sample of a gas has an initial volume of 14.1 L at a pressure of 2.31 atm. If the sample is compressed to a volume of 10.3 L, what is the resulting pressure?

8 Important Things from Chapter Five Boyles Law- P 1 V 1 =P 2 V 2 Charles Law- V 1 /T 1 =V 2 /T 2 Avogadro s Law- V 1 /n 1 =V 2 /n 2 Ideal gas law- PV=nRT Mole fraction= X= mol part/total mol Partial pressure= X*total pressure D= (P*mm)/RT KNOW THE CONCEPTS BEHIND THESE EQUATIONS Chapter Six 1. When 2.37 g of glucose (C 6 H 11 O 6 ) undergoes combustion in a bomb calorimeter, the temperature rises from 37.5 degrees C to 89.2 degrees C. Find the change in energy for the combustion of glucose in kj/mol. The heat capacity of the calorimeter, determined in a separate experiment, is 4.90 kj/degreec. 2. Label each of the following as endothermic or exothermic 1. Sweat evaporating from the skin 2. Water vapor condensing on a window 3. Ice sublimating A gas tank contains 15.7 g of butane, C 4 H Wood burning in a fire 3.. Calculate the heat in kj associated with the complete combustion of all the butane in the tank. 2C 4 H O 2 > 8CO H 2 O deltah= kj 4. There is a sample 22 g of water in a coffee cup calorimeter initially at 32 degrees Celsius. After absorbing 5.3 kj of heat, what is the final temperature? 5. 2 C (s) + 2H 2 O (g) > CH 4 (g) + CO 2 (g) Determine the standard enthalpy change for this reaction from the following standard enthalpies of reaction: 1. C (s) + H 2 O (g) > CO (g) + H 2 (g) deltah= kj 2. CO (g) + H 2 O (g) > CO 2 (g) +H 2 (g) deltah= kj 3. CH 4 (g) + H 2 O (g) > 3H 2 (g) + CO (g) deltah= kj

9 Important Things from Chapter Six Bomb calorimetry- q=c*deltat Coffee cup calorimetry- q=m*c*deltat w=-p*deltav deltah= deltae + P*deltaV deltae= q + w Chapter Seven 1. According to the quantum-mechanical model for the hydrogen atom, which electron transition would produce light with the longer wavelength, 2p > 1s or 3p > 1s? 2. Calculate the wavelength of the light emitted when an electron in a hydrogen atom makes the transition n=3 > n=2. 3. Which of the following sets of quantum numbers is impossible? 1. n=3 l=2 ml=0 2. n=4 l=1 ml=-2 3. n=3 l=1 ml=-1 4. n=2 l=0 ml=0 4. Calculate the energy of an electro magnetic radiation with a frequency of 7.0 x s Calculate the frequency of an electromagnetic radiation with a wavelength of nm. Important Things from Chapter Seven

10 Energy and wavelength are inversely proportional Chapter Eight 1. Find the electron configuration of the following elements 1. Cu 2. Ar 3. Br 2. Place the following in order of decreasing electron affinity. Na, F, Cl, Ge, N 3. Place the the same elements in order of increasing metallic character. 4. Use the periodic table to identify the element of each electron configuration 1. [Ar] 4s 2 3d 10 4p 6 2. [Kr] 5s 2 5. Choose the larger atom of each pair 1. Sn or Si 2. Br or Ga 3. C or F Important Things from Chapter Eight KNOW THE PERIODIC TRENDS Pauli Exclusion Principle: no two electrons in an atom can have the same four quantum numbers Aufbau Principle: The lowest energy orbitals must be filled first Hund s Rule: When filling orbitals, electrons must be filled singly at first with parallel spins Chapter Nine 1. Place the following compounds in order of decreasing lattice energy: NaCl, CaO, HCl 2. Draw the lewis structures of the following compounds 1. NO CO SeCl 5 3. Place the following compounds in order of increasing electronegativity: HI, BeF, LiI, CO 2 4. Which of the following compounds are polar? 1. H 2 O 2. CF 4

11 3. HCCl 3 4. O 2 5. Order the compounds in order of increasing carbon-carbon strength, HCCH, H 2 CCH 2, H 3 CCH 3 Important Things From Chapter Nine Know the periodic trends for lattice energy and electronegativity Know Born Haber Cycle Steps

12 Chapter Ten 1. What is the bond order of He 2? What does this bond order mean? 2. Determine the electron and molecular geometries of the following compounds 1. H 2 O 2. BF 3 3. SeCl 6 3. Name the hybridization scheme in each electron geometry 1. tetrahedral 2. linear 3. trigonal planar 4. Determine the hybridization of each carbon atom in the following caffeine molecule

13 Important Things From Chapter Ten