Name: ________________________________________________ Date: __________________________ Per: _______ College Preparatory Chemistry Level 1 Worksheet Book 1 Name: ________________________________________________ Date: __________________________ Per: _______ Scientific Method Put the following steps of the scientific method in the proper order. _____ Research the problem. _____ Observe and record. _____ Make a hypothesis. _____ Identify the problem. _____ Arrive at a conclusion. _____ Test the hypothesis. Match the following terms with the correct definition: a) organized process used to test a hypothesis ________ 1. hypothesis b) an educated guess about a solution to a problem ________ 2. control c) observations and measurements recorded during an experiment ________ 3. variable d) a judgement based on the results of an experiment ________ 4. experiment ________ 5. conclusion e) a logical explanation for events that occur in nature ________ 6. theory f) used to show that the result of an experiment is really due to the condition being tested ________ 7. data g) factor that changes in an experiment 2 Name: ________________________________________________ Date: __________________________ Per: _______ Matter Tree All matter can be classified as either a substance (element or compound) or a mixture (homogeneous or heterogeneous). Pure substances are homogeneous and you can write their chemical formula. There are two types of pure substances, elements and compounds. Elements are one type of atom while compounds are two or more different atoms chemically bonded together. Mixtures can have variable ratios. There are two types of mixtures, homogeneous and heterogeneous. A homogeneous mixture have the same composition all the way through. A heterogeneous mixture does not have the same composition all the way through. Classify the following as a substance or a mixture. If it is a substance choose either element or compound. If it is a mixture choose either heterogeneous or homogeneous. Choose 1 of the following: Substance Mixture Type of Matter Element Compound Homogeneous Heterogeneous 1. Chlorine 2. Water 3. Soil 4. Sugar Water 5. Oxygen 6. Carbon Dioxide 7. Mint Chocolate chip Ice Cream 8. Rubbing Alcohol 9. Pure Air 10. Iron 3 Name: ________________________________________________ Date: __________________________ Per: _______ Element Symbols Elements are given names and symbols. When writing the formulas of compounds, symbols are much easier to use than the names. We need to be familiar with the names and symbols of common elements. The symbol of an element is usually taken from the first one or two letters of the name of the element. However, sometimes the symbol comes from the Latin name of the element! Write the symbol for the following elements: 1. oxygen __________ 2. hydrogen __________ 3. chlorine __________ 4. mercury __________ 5. fluorine __________ 6. barium __________ 7. helium __________ 8. uranium __________ 9. radon __________ 10. sulfur __________ Write the name of the element that corresponds to each of the following symbols: 11. Kr _________________________ 12. K _________________________ 13. C _________________________ 14. Ne _________________________ 15. Si _________________________ 16. Zr _________________________ 17. Sn _________________________ 18. Pt _________________________ 19. Na _________________________ 20. Al _________________________ 4 Name: ________________________________________________ Date: __________________________ Per: _______ Physical vs. Chemical Properties A physical properties is observed with the senses and can be determined without destroying the object. For example, color, shape, mass, length and odor are all examples of physical properties. A chemical property indicates how a substance reacts with something else. The original substance is fundamentally changed in observing a chemical property. For example, the ability of iron to rust is a chemical property. The iron has reacted with oxygen, and the original iron metal is changed. It now exists as iron oxide, a different substance. Classify the following properties as either chemical or physical by putting a check in the appropriate column. Physical Property 1. Blue Color 2. Density 3. Flammability 4. Solubility 5. Reacts with acid to form H2. 6. Supports combustion 7. Sour Taste 8. Melting Point 9. Reacts with water to form a gas 10. Reacts with a base to form water 11. Hardness 12. Boiling Point 13. Can neutralize a base 14. Luster 15. Odor 5 Chemical Property Name: ________________________________________________ Date: __________________________ Per: _______ Physical vs. Chemical Changes In a physical change, the original substance still exists, it has only changed form. In a chemical change, a new substance is produced. Energy changes always accompany chemical changes. Classify the following as being a physical or chemical change. 1. Sodium hydroxide dissolves in water. 2. Hydrochloric acid reacts with potassium hydroxide to produce a salt, water and heat. 3. A pellet of sodium is sliced in two. 4. Water is heated and changed to steam. 5. Potassium chlorate decomposes to potassium chloride & oxygen gas. 6. Iron rusts. 7. When placed in H2O, a sodium pellet catches on fire as hydrogen gas is liberated and sodium hydroxide forms. 8. Evaporation. 9. Ice melting. 10. Milk sours. 11. Sugar dissolves in water. 12. Wood rotting. 13. Pancakes cooking on a griddle. 14. Grass growing in a lawn. 15. A tire is inflated with air. 16. Food is digested in the stomach. 17. Water is absorbed by a paper towel. 6 Name: ________________________________________________ Date: __________________________ Per: _______ Metrics and Measurement Scientists use the metric system of measurement, based on the number 10. It is important to be able to convert from one unit to another. kilo (k) 1000 103 hecto (h) 100 102 deca (da) 10 101 BASE UNIT Gram (g) Liter (L) Meter (m) deci (d) .1 10-1 centi (c) .01 10-2 milli (m) .001 10-3 Using the above chart, we can determine how many places to move the decimal point and in what direction by counting the places from one unit to another. Convert the following: 1) 35 mL = ____________________ dL 6) 4,500 mg = ____________________ g 2) 950 g = ____________________ kg 7) 25 cm = _______________________ mm 3) 275 mm = ____________________ cm 8) 0.005 kg = ____________________ dag 4) 1,000 L = ____________________ kL 9) 0.075 m = ____________________ cm 5) 1,000 mL =____________________ L 10) 15 g = 7 ____________________ mg Name: ________________________________________________ Date: __________________________ Per: _______ Scientific Notation Scientists very often deal with very small and very large numbers, which can lead to a lot of confusion when counting zeros! We have learned to express these numbers as powers of ten. Scientific notation takes the form of M x 10n, where 1 < M < 10 and “n” represents the number of decimal places to be moved. Positive “n” indicates the standard (decimal) form is larger than zero whereas a negative “n’ would indicate a number smaller than zero. Example 1: Convert 1,500,000 to scientific notation. We move the decimal point so that there is only one digit to its left, a total of 6 places. 1,500,000 = 1.5 x 106 (“n” is positive because original number is larger than 0) Example 2: Convert 0.000025 to scientific notation. For this example, we move the decimal point 5 places to the right, again so that there is only one digit to its left. 0.000025 = 2.5 x 10-5 (“n” is negative because original number is smaller that 0) Example 3: Convert the 9.6 x 10-4 into standard notation Because “n” is negative, this indicates that the number is smaller than 0. This means that we move the decimal point 4 places to the left. 9.6 x 10-4 = 0.00096 Convert the following into scientific notation: Convert the following into standard notation: a. 0.005 = _______________ a. 1.5 x 103 = _______________ b. 5,050 = _______________ b. 1.5 x 10-3 = _______________ c. 0.0008 = _______________ c. 3.75 x 10-2 = _______________ d. 0.250 = _______________ d. 3.75 x 102 = _______________ e. 0.025 = _______________ e. 2.2 x 105 = _______________ f. 0.0025 = _______________ f. 3.35 x 10-1 = _______________ g. 500.0 = _______________ 8 Name: ________________________________________________ Date: __________________________ Per: _______ Significant Figures Worksheet 1. Determine the number of significant figures in the following, then write the numbers in scientific notation: # of Significant Scientific Notation Figures a. 200000000 b. 0.0000003287 c. 3,200 d. 4850000000000 e. 0.00000000398700 f. 0.000000000000004790 2. Perform the indicated operation using scientific notation. Remember significant figures!!! a. 4800000 / 12000000000 ____________________ b. (300000) (230000000) ____________________ c. 0.0000004 x 0.400 ____________________ 3. Complete the following and report the answer to the correct number of significant figures. a. 4.320 / 8.7 x 3.209 ____________________ b. 1.962 + 3.14 + 14.7 ____________________ c. 3.0006 – 2.8 ____________________ d. (3.20 + 7) x 8.0 ____________________ 9 Name: ________________________________________________ Date: __________________________ Per: _______ Density Which has a greater mass, air or lead? Most of you would answer lead, but actually this question does not have an answer. To compare these two things you need to know how much of each you have. A large amount of air could have a greater mass than a small amount of lead. To compare different things, we have to compare the masses of each that occupy the same space, or volume. This is called density. Density = Mass Volume You can remember that density is a broken heart (M/V) Solve the following problems. Remember to use the correct number of significant figures! 1) What is the density of carbon dioxide gas if 0.196 g occupies a volume of 100.0 mL.? _____________ 2) A block of wood 3.0 cm on each side has a mass of 27 g. What is the density of this block? _____________ 3) An irregularly shaped stone was lowered into a graduated cylinder holding a volume of water equal to 2.0 mL. The height of the water rose to 7.0 mL. If the mass of the stone is 25 g, what is the density? _____________ 4) A 10.0 cm3 sample of copper has a mass of 89.6 grams. What is the density of copper? _____________ Accuracy vs. Precision 1. What is meant by the term “accuracy”? 2. What is meant by the term “precision”? 3. Under what circumstances could a series of measurements of the same quantity be precise but inaccurate? 10 Name: ________________________________________________ Date: __________________________ Per: _______ 4. Which of the following synonyms or characteristics apply to the concept of accuracy and which apply to precision? a. multiple measurements b. correct c. repeatable d. reproducible e. single measurement f. true value 5. Three students made multiple weighings of a copper cylinder, each using a different balance. The correct mass of the cylinder had been previously determined to be 47.32 g. Describe the accuracy and precision of each student’s measurements. Mass of cylinder (g) Lissa Lamont Leigh Anne Weighing 1 47.13 47.45 47.95 Weighing 2 47.94 47.39 47.91 Weighing 3 46.83 47.42 47.89 Weighing 4 47.47 47.41 47.93 11 Name: ________________________________________________ Date: __________________________ Per: _______ Temperature & its Measurement Temperature (which measures the average kinetic energy of the molecules) can be measured using three common scales: Celsius, Kelvin, & Fahrenheit. We use the following formulas to convert from one scale to another. Celsius is the scale most desirable for laboratory work. Kelvin represents the absolute scale. Fahrenheit is the old English scale, which is never used in lab! C = K – 273 K = C + 273 F = 9/5C + 32 C = 5/9(F – 32) Complete the following table. C 1. 0C K 2. F 212 F 3. 450 K 4. 5. 98.6 F -273 C 6. 294 K 7. 77F 8. 225 K 9. -40C 12 Name: ________________________________________________ Date: __________________________ Per: _______ Percentage Error Percentage error is a way for scientists to express how far off a laboratory value is from the commonly accepted value. The formula is: % error = Accepted Value – Experimental Value x 100 Accepted value ~ absolute value Determine the percentage error in the following problems: 1. Experimental value = 1.24 g Accepted value = 1.30 g Answer 2. Experimental value = 1.24 x 10-2 g Accepted value = 9.98 x 10-3 g Answer 3. Experimental value = 252 mL Accepted value = 225 mL Answer 13 Name: ________________________________________________ Date: __________________________ Per: _______ Atomic Structure 1 An atom is made up of protons and neutrons (both found in the nucleus) and electrons (in the surrounding electron cloud). The atomic number is equal to the number of protons. The mass number is equal to the number of protons plus neutrons. In a neutral atom, the number of protons is equal to the number of electrons. The charge on an ion indicates an imbalance between electrons and protons. Too many electrons produces a negative charge, too few, a positive charge. This structure can be written as part of a chemical symbol. Example: mass number 15 3+ charge 7N atomic number Complete the following table: Element/Ion Atomic # H Atomic mass Mass # # Protons # Neutrons 1 H+ 0 12C 6 7 Li+ 3 35Cl17 39K 19 24Mg2+ 12 As3- 74 Ag 60 Ag+ 61 S2- 32 U 238 14 # Electrons Name: ________________________________________________ Date: __________________________ Per: _______ Atomic Structure 2 1. What is Dalton’s Atomic Theory? Are there any parts of this theory that are no longer valid? 2. Describe JJ Thompson’s “Plum Pudding” Model of the atom. Discuss what the limitations of this model are. 3. Describe Rutherford’s Gold Foil Experiment and discuss what information it gave us about the structure of an atom. (Include a drawing) 4. What three subatomic particles make up the atom? What are the relative masses of each? 5. What is the charge on each of the three particles listed in number 4? 6. How is an ion formed? 7. What is an isotope? 8. What is needed to determine the average atomic mass of an element? 15 Name: ________________________________________________ Date: __________________________ Per: _______ Isotopes & Average Atomic Mass Elements come in a variety of isotopes, meaning they are made up of atoms with the same atomic number but different atomic masses. These atoms differ in the number of neutrons. The average atomic mass is the weighted average of all of the isotopes of an atom. 133 Example: A sample of cesium is 75% Cs, 20% What is its average atomic mass? Answer: 132 Cs, and 5% 134 Cs. .7500 x 133 = 99.75 .200 x 132 = 26.4 .0500 x 134 = 6.7 total 132.9 amu = average atomic mass Determine the average atomic masses of the following: 1. 127 80.0% I 126 17.0% I 128 3.0% I 2. 197 50.0% Au 198 50.0% Au 3. 15.0% 85.0% Answer Answer Answer 55 Fe 56 Fe 16 Name: ________________________________________________ Date: __________________________ Per: _______ Electron Configuration Worksheet #1 1. What are valence electrons? 2. How many valence electrons do the following elements have a. Be f. Ca b. C g. K c. Br h. Ar d. Xe i. Al e. V j. He 3. Write the electron configurations for the following elements: a. Cr b. Cl c. O d. Ca e. Te f. Kr 17 Name: ________________________________________________ Date: __________________________ Per: _______ x Types of Reactions Worksheet 1. Balance the following reactions. Then, indicate the type of reaction for each equation: a. ____ MgBr2 + ____ Cl2 ____ MgCl2 + ____ Br2 _______________ b. ___ Pb(NO3)2 + ____ H2S c. ____ HgO ____ Hg d. ____ Sb + ____ Cl2 e. ____ CuO + ____ H2 ____ Cu ____ PbS + + ____ HNO3 _______________ + ____O2 _______________ ____ SbCl3 _______________ ____ H2O _______________ 1. Write and balance the equations for the following reactions. Be sure to include the state of matter for example (s) for solid. a. aqueous sodium chloride reacts with aqueous lead (II) nitrate to yield a lead (II) chloride precipitate and aqueous sodium nitrate b. silver nitrate reacts in solution with potassium chromate to yield a silver chromate precipitate and soluble potassium nitrate c. solid calcium carbonate reacts with hydrochloric acid [HCl(aq)] to yield aqueous calcium chloride, carbon dioxide gas, and liquid water 18 Name: ________________________________________________ Date: __________________________ Per: _______ 2. Determine the type of reaction, predict the products and balance the following: a. N2 + H2 b. Sn + Cl2 c. Fe + HCl d. MgCl2 + LiI Mole Worksheet 3 19 Name: ________________________________________________ Date: __________________________ Per: _______ 1. An extra strength aspirin tablet contains 500. mg of aspirin (C9H8O4). How many molecules of aspirin are in one extra strength tablet? 2. A block of salt contains 3.45 x 1026 formula units of NaCl. How many grams is this? __________ __________ 24 3. A sample of barium nitrate contains 6.80 x 10 formula units. How many grams is this? 4. __________ If you burned 4.0 x 1024 molecules of natural gas, or methane (CH4), during a laboratory experiment, what mass of methane did you burn? __________ 5. How many hydrogen atoms are in 3.5 g of NaOH? Oxygen atoms? __________ 20 Name: ________________________________________________ Date: __________________________ Per: _______ Molarity 1 1) Molarity is a measure of the C____________________ of a solution. It is calculated by dividing the m__________ by the L________________. The units for molarity are M or _____________________. 2) Find the molarity of the following solutions: (Show work!) a. 2.30 moles dissolved to make 2.0 Liters of solution. b. 0.250 moles dissolved to make 300.0 mL of solution. c. 0.450 moles dissolved to make 605.0 mL of solution. 3) Find the volume of the following: (Show work!) a. A 0.308 M solution with 4.3 moles dissolved. b. 3.42 moles in a 5.0 M solution. c. 2.57 M solution with .025 moles dissolved. 21 Name: ________________________________________________ Date: __________________________ Per: _______ Percent Composition Worksheet Determine the percent composition of each atom in the following compounds: 1. H3PO4 2. NaF 3. CuFeS2 4. C6H12O6 Empirical and Molecular Formulas Worksheet 1. Determine the empirical formulas of the following; a. 63.0 g Rb and 5.90 g O d. 42.7% Co, 57.3% Se e. 48.8% Cd, 20.8% C, 2.62% H, 27.8% O 22 Name: ________________________________________________ Date: __________________________ Per: _______ Stoichiometry Worksheet #1 Remember to balance all equations!!! 1. How many moles of hydrochloric acid are required to completely dissolve 2.6 moles of magnesium hydroxide? Mg(OH)2 (s) + HCl (aq) MgCl2 (aq) + H2O (l) 2. Mrs. Loughman found a container of solid sodium hydroxide in the chemical storeroom at Framingham High School. She needs to neutralize this with sulfuric acid. If she found 56.8 moles, how much sulfuric acid will she need to completely neutralize the sodium hydroxide? NaOH (s) + H2SO4 (aq) H2O (l) + Na2SO4 (aq) 3. How many moles of O2 are required to burn 1 mol of C3H8 (propane) molecules in a camping stove? 4. How many moles of O2 molecules are required to burn 1 mol of CH4 molecules from a Bunsen burner? 23 Name: ________________________________________________ Date: __________________________ Per: _______ Freezing and Boiling Point Graph 25 E Temperature °C 20 D 15 10 5 C B A 0 -5 Energy Answer the following questions using the chart above: 1) What is the freezing point of the substance? _____________________ 2) What is the boiling point of the substance? _____________________ 3) What is the melting point of the substance? _____________________ 4) What letter represents the range where the solid is warmed? _____________________ 5) What letter represents the range where the liquid is warmed? _____________________ 6) What letter represents the range where the vapor is warmed? _____________________ 7) What letter represents the melting of the solid? _____________________ 8) What letter represents the vaporization of the liquid? _____________________ 9) What letter(s) show a change in the potential energy? _____________________ 10) What letter(s) show a change in the kinetic energy? _____________________ 11) What letter represents condensation? _____________________ 12) What letter represents crystallization? _____________________ 24 Name: ________________________________________________ Date: __________________________ Per: _______ Heat Calculations Heat is measured in units of joules or calories. The amount of heat given off or absorbed can be calculated by the following formula. q = m x C x T Heat = (mass in grams) (specific heat) (temperature change) The specific heat for water is 4.18 joules/grams C Solve the following problems: 1. How many joules are absorbed by a pot of water with a mass of 500. grams in order to raise the temperature from 20.0 C to 30.0 C? 2. If the specific heat of iron = 0.460 J/gC, how much heat is needed to warm 50.0 g of iron from 20.0C to 100.0C? Heat and Phase Changes During a phase change, the temperature remains the same. For these calculations, we use the following formulas. For freezing and melting Heat energy = (moles) (Molar heat of fusion) For boiling and condensation (moles) (Molar heat of vaporization) Molar Heat of fusion of water = 6.02 kJ/mol Molar Heat of vaporization of water = 40.7kJ/mol Solve the following problems 1) How many joules of heat are necessary to melt 500. g of ice at its freezing point? 2) How many kilojoules is this? 25 Name: ________________________________________________ Date: __________________________ Per: _______ 3) How much heat is necessary to vaporize 780.5 g of water at its boiling point? Heat and its Measurement Heat (or energy) can be measured in units of calories or joules. When there is a temperature change (T), heat (q) can be calculated using the formula: q = mass x specific heat capacity x ∆T T = Temperature (Final) – Temperature (Initial) During a phase change, we use the formula: q = moles x molar heat of fusion (or heat of vaporization) Answer the following: 1) Define: Specific Heat Capacity: Heat of Fusion: Heat of Vaporization: 2) When should you use the formula q=mCT and when should you use the formula q=nH? 3) How many joules of heat are given off when 5.00 grams of water cools from 75.0°C to 25.0°C? (Specific Heat of Water = 4.18 J/g°C) 26 Name: ________________________________________________ Date: __________________________ Per: _______ Nuclear Chemistry Worksheet Radioactive Decay Processes Radioactive decay processes involve the emission or capture of a number of different particles. Many radioactive processes result in the change of either the mass number or the atomic number of the atom undergoing the change. There are two exceptions to this general statement. In the first exception, alpha particle emission, both the atomic number and the mass number decrease. When gamma radiation is emitted, neither the atomic number nor the mass number changes. However the emission of gamma radiation always accompanies another radioactive process. Summary of Typical Radioactive Processes Change in nucleus Example Emission Alpha Mass Number (-4) Atomic Number (-2) Beta Positron Neutron Atomic Number (+1) 14C 14N+ 0 e 6 7 -1 Atomic Number (-1) 64Cu 64Ni + 0 e 29 28 +1 Mass Number (-1) Electron Capture 218Fr 214At + 4 He 87 85 2 Atomic Number (-1) 137I 136I + 1 n 43 53 0 195Au + 0 e 195Pt 79 -1 78 In addition to the reactions shown in the table, atoms can be bombarded with alpha particles, neutrons, or other atoms to synthesize different radioactive isotopes. These reactions are called transmutation reactions. 1) What is the composition of the nucleus of the following isotopes? Isotope Protons 64Ni 28 Neutrons 136I 53 195Au 79 2) Complete the following equations of radioactive decay. 4 a. 241 95 Am 2 He + ________ 0 b. 81 37Rb ________ + +1e 50 c. 50 26Fe 27Co + ________ (Next page for More!) 27 Name: ________________________________________________ Date: __________________________ Per: _______ 3) Predict the products of the following nuclear reactions. It helps to determine what type of nuclear decay takes place in each reaction. Remember to keep track of the total mass number and atomic number on both sides of the reaction. Also, keep in mind that coefficients require the atomic numbers and mass numbers to be multiplied by that numerical value (of the coefficient). If there are any missing atomic or mass numbers, you may obtain them from the periodic table. 0 a. 42K _______ -1e + b. 239Pu 4 He 2 + _______ c. 235 92 U 231Th + 90 _______ d. 11 H + 3H 1 _______ 28 Name: ________________________________________________ Date: __________________________ Per: _______ Gas Laws Worksheet #2 We have now talked about two major gas laws, the combined gas law and the new ideal gas law, PV = nRT. You need to know when to use each. When do you use the combined gas law? 1. 9.00 moles of a gas at 347C and 102.7 kPa occupy what volume? Which gas law should you use and why? 2. 7.65 moles of a gas have a volume of 32.5 L at 560 mmHg, what is the temperature? 3. If I have a balloon with a volume of 4.5 liters, and a pressure of 567 mmHg, what will the pressure be when the volume is 2.5 liters? 4. 15 mL of a gas is collected at 25C and 650 mmHg. What is the volume at STP? 6. 2.5 L of a gas at 64C and 700 mmHg is now subjected to a temperature of -33C and a pressure of 900 mmHg. What is the new volume? 29 Name: ________________________________________________ Date: __________________________ Per: _______ Bonding/Solutions Worksheet #2 1. Classify the following compounds as ionic or covalent: a. MgCl2 b. Na2S c. H2O d. H2S 2. Draw the Lewis Dot Structure and then use the VSEPR theory to predict the shape of the following molecules: a. CO2 b. H2Se c. SiCl4 d. SCl2 30 Name: ________________________________________________ Date: __________________________ Per: _______ Bonding/Solutions Worksheet Use the solubility curve to answer the following questions: 1. Which salt shows the smallest change in solubility with increasing temperature? _________________ 2. What mass of ammonium chloride can be dissolved in 200 g of water at 70C? ___________________ 3. If 90 grams of potassium nitrate are dissolved in 200 grams of water at 50C, what type of solution is this? (circle one) unsaturated, saturated, supersaturated 4. What happens to the solubility of ammonia as the temperature increases? ______________________ 5. If a saturated solution (in 100 g of water) of KClO3 is prepared at 90C and then cooled to 40C, what mass of KClO3 will precipitate? 6. What mass of potassium chloride can be dissolved in 175 g of water at 40C? 7. Which salt is the most soluble at 60C? ________ 8. What affect does stirring have on the rate at which a solution forms? Explain your answer. 9. What affect does the size of the particle have on the rate at which a solution forms? Explain your answer. 31 Name: ________________________________________________ Date: __________________________ Per: _______ Molarity Worksheet 2 Calculate the molarity of the following: 1. There are 2.3 moles of sodium chloride dissolved in 0.45 L of solution. 2. You have 0.0905 moles of sodium sulfate dissolved in 12.0 mL of solution. 3. You dissolve 0.885 moles of magnesium acetate in 5.67 liters of solution. Use the information given to complete the calculations below: 4. 45.4 g of ammonia are dissolved in enough water to make 0.750 L of solution. 5. What mass of NaOH is required to prepare 1.57 L of a 2.34 M solution? 6. What mass of Na2SO4 is required to prepare 0.750 L of a 0.250 M solution? 32 Name: ________________________________________________ Date: __________________________ Per: _______ Rate Worksheet #1 1. Define the following terms: a. Rate of reaction b. Activation energy c. Activated complex d. Transition state e. Catalyst f. Inhibitor g. Entropy 2. What is the collision theory and why is it important? 3. Label the following graph: Reactants, Products, Activation energy, Activated complex/transition state, Heat of reaction, Energy, Reaction coordinate (progress) 33 Name: ________________________________________________ Date: __________________________ Per: _______ Rate Worksheet #2 1. Know the definitions of the following terms; Reversible reaction Le Chatelier’s Principle Equilibrium Equilibrium constant 2. Write the equilibrium constant expression for the following unbalanced reactions: a. Br2 (g) + H2S (g) HBr (g) + S (s) b. CaCO3 (s) CaO (s) + c. Cl2 (g) + CS2 (g) CCl4 (g) CO2 (g) + S2Cl2 (g) 3. Le Chatelier’s Principle states that when a system at equilibrium is subjected to a stress (a change), the system will shift its equilibrium point in order to relieve the stress. Complete the following chart by writing LEFT, RIGHT, or NONE for equilibrium shift, and DECREASE, INCREASE, or REMAINS THE SAME for the concentrations of reactants and products, and for the value of K. (Remember, pure liquids and solids do not affect equilibrium values) H2 (g) Stress 1. add H2 2. add I2 3. add HI 4. remove H2 5. remove I2 6. remove HI 7. increase temp 8. decrease temp 9. increase pressure 10. decrease pressure + I2 (g) Equilibrium Shift Right 2HI (g) [H2] --- [I2] decrease ∆H= +52.7 kJ [HI] increase ----------- 34 Keq same Name: ________________________________________________ Date: __________________________ Per: _______ 4. Using the following equation: I2 (g) 2I (g) A. If the equilibrium concentrations are as follows: [I2] = 1.2 M, [I] = 0.640 M write the Keq expression for the reaction. B. Calculate the value of Keq. 6. Find the Keq for the reaction if [H2S] = 0.015 M, [H2] = 0.010 M, and the [S2] = 0.051 M. 2 H2S(g) 2 H2 (g) + S2 (g) 35 Name: ________________________________________________ Date: __________________________ Per: _______ [H+] x [OH-] = 1.0 x 10-14 pH + pOH = 14 [H+] = 10-pH [OH-] = 10-pOH pH = - log[H+] pOH = - log[OH-] Acid Base Worksheet 2. 3. Write the names for the following acids and bases: a) KOH ____________________________________ b) H2SO4 ____________________________________ c) C2H3O2H ____________________________________ d) Fe(OH)2 ____________________________________ If 0.001 moles of KOH are added to 0.1 L of solution, what is the: a. pH b. pOH 4. When a student performs a titration in lab, he finds that it takes 23.2 mL of .340 M HCl to neutralize 14.1 mL of NaOH. What is the concentration of the NaOH? 1. What volume of 0.500 M HCl is required to neutralize 54.6 mL of 1.2 M KOH? 2. What is the molarity of a solution of NaOH if it takes 45.7 mL of a .750 M solution of HNO3 to neutralize 43.9 mL? 36 Name: ________________________________________________ Date: __________________________ Per: _______ 3. If 0.0025 moles of H2SO4 are added to 1.0 L of solution, what is the: c. pH d. pOH 4. Determine the Bronsted-Lowry acid-base pairs for the following reactions: a. HSO3+ H2O SO32+ H3O+ b. HNO3 + H2O NO3- c. HC4H7O2 + H2O C4H7O2- + H3O+ + 3. If 0.0025 moles of H2SO4 are added to 1.0 L of solution, what is the: a. pH b. pOH 37 H3O+