Name:____________________________ Date:_____________ Period:____ Review: Chemistry I End of Course Exam Unit 1: Measurement and Lab Skills Unit 2: Properties of Matter Unit 3: Atomic Theory and Structure Unit 4: Electron Configuration and Modern Atomic Theory Unit 5: The Periodic Table Unit 6: Ionic Compounds – Bonding and Nomenclature Unit 7: Covalent Compounds – Bonding and Nomenclature Unit 8: Percent Composition and Empirical Formulas Unit 9: Chemical Reactions Unit 10: Stoichiometry Unit 11: Energy Changes and Reaction Rates Unit 12: States of Matter Unit 13: Kinetic-Molecular Theory and Gases Unit 14: Solutions and Equilibrium Unit 15: Acids and Bases Matter and its Properties 1. Place a check mark next to each item that is matter which is made of atoms (Remember that matter has mass and takes up space). ____a. apple ______b. air _____c. light ____d. energy ____f. heat ____g. water 2. Which type of substance (element, compound, or mixture) is represented in each diagram below. 3. T or F T or F T or F T or F ________ ________ ________ ________ 1. _______________________ 2. _______________________ 3. _______________________ 4. _______________________ a. Elements can be broken down by both physical and chemical means. b. Compounds can only be broken down by chemical means. c. Mixtures can be separated into different components using physical means. d. Air is a homogeneous mixture of O2, CO2, N2 and water vapor. 4. Classify the following materials as: element compound homogeneous mixture Can be separated by _____ means. heterogeneous mixture (circle one) a. cheeseburger ___________________ physical chemical NO b. salt water ___________________ physical chemical NO c. air ___________________ physical chemical NO d. hydrogen gas (H2) ___________________ physical chemical NO e. silver (Ag) ___________________ physical chemical NO f. steam (H2O) ___________________ physical chemical NO g. table salt (NaCl) ___________________ physical chemical NO h. carbon dioxide (CO2) ___________________ physical chemical NO i. ice (H2O) ___________________ physical chemical NO 5. a. Which type of matter contains only ONE TYPE of atom? (element, compound, or mixture) b. Which type of matter contains two or more different atoms, chemically bonded together? (element, compound, or mixture) Match each item with the correct statement below. A. element B. compound C. heterogeneous mixture D. homogeneous mixture ___ 6. describes mixture with a non-uniform composition (has different parts) ___ 7. pure substance that cannot be changed into simpler substances by physical means ___ 8. pure substance that cannot be broken down by chemical means ___9. A uniform mixture (such as air or sugar water) in which the parts are not easy to distinguish 10. What is one difference between a mixture and a compound? A. B. C. D. A compound has the same properties as the elements that form it. A compound can only be separated physically. A mixture can be separated physically. A mixture must be uniform in composition. Energy and its Interactions 11. Label each of the following processes as endothermic or exothermic: ______________ solid to liquid to gas ______________ gas to liquid to solid ______________ solid ice melting into liquid ______________ liquid water evaporating into gas ______________ water vapor condensing into liquid ______________ liquid water freezing into solid ice 12. Sketch a potential energy diagram for an exothermic reaction. Label the reactants and products. potential energy reaction progress Circle the correct statement. 13. In an exothermic reaction, heat is ( absorbed from / released to ) the surroundings, and the surroundings ( cool down / warm up). Touching a beaker containing this reaction would feel (cool / warm ) In an exothermic reaction, the energy of the reactants is (higher/ lower) than the energy of the products. 14. Sketch a potential energy diagram for an endothermic reaction. Label the reactants and products. potential energy reaction progress Circle the correct statement. In an endothermic reaction, heat is ( absorbed from / released to) the surroundings, and the surroundings ( cool down / warm up) Touching a beaker containing this reaction would feel (cool / warm ). In an endothermic reaction, the PE of the reactants is (higher/ lower) than the PE of the products. Measurement and Density 15. These values were recorded as the mass of products when the same chemical reaction was carried out three separate times: 3.20 g; 2.87 g; 3.89 g. a. Find the average mass. Average mass = _______________________________ b. The theoretical mass of products from that reaction was 3.45 g. Calculate the % error. % error = _________________________ c. Was the experiment accurate (i.e was the % error < 10%)? d. Is the set of data precise? e. What is the difference between accuracy and precision?: 16. Convert: 65.5 m = ?? cm __________________ 17. Convert 2.3 mL into L. _____________________ 18. The mass of a soft lump of metal is 214 g, and the volume is 11.3 cm3. a. What is the formula for density? 3 b. What is the density of the metal in g/cm ? c. Using the table of metal densities, Density Table Metal Density (in g/cm3) Aluminum Iron Gold Platinum 2.7 7.9 19.3 21.4 identify the metal: _______________ The soft metal lump is then smushed together with another lump of the exact same soft metal. The density of the new larger lump is ( greater than / equal to / less than) the original lump. Atomic Theory and Structure Recall that there are 3 types of subatomic particles- protons are (+), are found in the nucleus, and have nearly the same mass as a neutron (1 a.m.u). Electrons are (-), are found in the electron cloud, and have nearly no mass when compared to protons or neutrons. Neutrons are like protons, only neutral. Atomic number = # of protons Mass number = # proton + # neutrons To find neutrons, subtract! Mass number – atomic number = # of neutons Since atoms are neutral, the # of protons = # of electrons 19. Which of the following is FALSE about subatomic particles? A. B. C. D. Electrons are negatively charged and are the lightest subatomic particle. Protons are positively charged and have nearly the same mass as neutrons. Neutrons have no charge and have no mass. The mass of a neutron nearly equals the mass of a proton. 20. All atoms of the same element have the same ____. A. B. C. D. number of neutrons number of protons mass numbers mass 21. What are atoms of the same element with different numbers of neutrons? A. B. C. D. ions atoms numbers of electrons isotopes 22. Define isotope. Give an example of a pair of isotopes. ___________________________________________________________________ ___________________________________________________________________ 75 35X 23. Element X has an atomic number of 35 and a mass number of 75. How many of each subatomic particle are in a neutral atom of the element? A. B. C. D. 35 protons, 35 neutrons, and 70 electrons 35 protons, 75 neutrons, and 35 electrons 75 protons, 35 neutrons, and 40 electrons 35 protons, 40 neutrons, and 35 electrons 24. 15 moles of sodium and 15 moles of carbon have the same number of _________. A. B. C. D. atoms grams A and B NONE of the above 25. What is the molar mass of Fe3(PO4)2 ? of CaCl2? Define mole:___________________________________________________________________ What is Avogadro’s number? ___________________________________________________ 26. Convert 4.50 moles of Fe to atoms of Fe. 27. Convert 4.03 x 1022 molecules of H2O to moles of H2O. Electron Configuration and Modern Atomic Theory Figure 1: Bohr Model 28. Examine the Bohr Model in Figure 1. Place a “G” in the box that points to the “Ground State” electron orbit. Place an “E” in the box that points to the “Excited State” electron orbit. Nucleus How is the “excited state” different from the “ground state?” ____________________________________________________________ eelevel 3 Figure A: electron move from high to low orbit Einitial photon Figure B: level 5 electron move from low to high orbit E) photon E) e- level 2 level 1 e- Efinal Efinal Einitial E initial 29. Study Figures A and B above. In which figure is energy absorbed? A or B How do you know? _________________________________________________________ In which figure is energy emitted? A or B How do you know? _________________________________________________________ Which figure shows a photon of the greatest energy? A or B How do you know? _________________________________________________________ 30. Write the number of valence electrons for the elements in each group in the boxes. 31. Complete the table. Element Symbol # of VALENCE Electrons Electron Configuration Bohr Model 1s2 2s2 2p6 3s2 3p6 Carbon C [Ar] 4s2 The Periodic Table 32. A chemist needs calcium to perform an experiment in the lab and discovers that she does not have any calcium. List the two elements that she could use for this experiment to best replace calcium. _______________________ _____________________ Explain your choices: ______________________________________________________________ Why do elements that are in the same group behave in a similar way? __________________________________________________________________ What is the radius trend moving across a period?__________________ What is the radius trend moving down a group?______________________ What is the largest atom? __________________ The smallest atom? _______________ 33. For the elements listed above, which element has the largest atomic radius? ____ Which element has the smallest atomic radius? ____ These atoms change size from left to right. Why do their sizes follow this trend from left to right? ______________________________________________________________________________ Ionization energy is the energy needed to remove the outermost electron from an atom. It is difficult to remove electrons from small atoms, and easier to remove them from large atoms, so… I.E is inversely proportional to radius. 34. Arrange the elements above from lowest to highest ionization energy. _____ < _____ < _____ < _____ 35. Fill in the missing information for the element fluorine. a. F has the ___________ atomic radius in its group. b. F has the ___________ ionization energy in its group. c. F has the ___________ electronegativity in its group. d. F is the __________ reactive element in its group. Ionic Compounds – Bonding and Nomenclature 36. In an ionic bond, electrons are ( shared / transferred / connected ) between atoms. (circle one) 37. An ionic bond is a chemical bond caused by electrostatic _________________________ between ______________ and _____________ that is formed by _________________________ electrons between atoms. (Word bank: cation, transfer, anion, attraction) Ionic bonds always from between ___________ and ___________. (metals, nonmetals, metalloids) 38. For the pairs of elements listed below, circle pairs that would likely form ionic bonds. Remember, an ionic bond forms between a METAL and a NONMETAL. C and H Na and F Hg and Ag Mg and S N and C K and O 39. How did you know which elements in Question 38 above would form ionic bonds? 40. Name the following compounds. (Some compounds may need a Roman numeral**.) Fe2O3 _______________________** NaBr _______________________ CuCl2 _______________________ ** AlCl3 _______________________ 41. Write a formula for the following chemical compounds. copper(II) oxide ______________ calcium sulfide ______________ magnesium iodide ______________ nickel(II) bromide ______________ Covalent Compounds – Bonding and Nomenclature 42. Why do atoms share electrons in covalent bonds? ________________________________________________________________ 43. Which of the following bonds is the most polar (or has the greatest difference in electronegativity)? A. B. C. D. C—C H—N O—H H—Cl 44. Which is TRUE of a nonpolar covalent bond? A. B. C. D. electrons are shared unequally between atoms . a cation is bonded to an anion electrons are transferred between atoms electrons are shared equally in atoms water molecule water molecule 45. There are strong attractions between polar water molecules which cause water to have all of the following properties EXCEPT ____. A. B. C. D. surface tension liquid of greater density than solid (ice) attraction to nonpolar molecules higher boiling point 46. Hydrogen sulfide (H2S) boils at –60oC. Even though water is a smaller molecule that should become a gas easier than H2S, water doesn’t boil until it reaches 100oC. Why do water molecules require a much higher temperature to become a gas? ___________________________________________________________________ For #47-49, write the NAME or FORMULA for the following molecular compounds: Covalent compounds are named using prefixes- mono-, di-, tri-, tetra-, penta-, etc. 47. CCI4 ______________________________ S2O3 ______________________________ CS2 _______________________________ 48. tetraphosphorus pentoxide _______ carbon dioxide _______ carbon monoxide _______ 49. What is the ending (suffix) used when naming binary compounds? For #50-52, DRAW the Lewis dot structures for the following compounds. Step 1: Determine the total # of valence electrons. Step 2: Arrange the electrons so that each atom is surrounded by 8 electrons. Remember that elements in Group 17 can make only one bond, while Group 16 can make two bonds, Group 15 can make 3 bonds, and Group 14 (carbon) can make up to 4 bonds. 50. HBr 51. N2 52. a. CO2 b. O2 c. NH3 d. H2O e. HCN Percent Composition and Empirical Formulas 𝒑𝒂𝒓𝒕 % composition = 𝒘𝒉𝒐𝒍𝒆 x 100 53. What is the percent composition of carbon in Na2CO3 ? The empirical formula is the simplest, or reduced version of a chemical formula. Ex. Sugar has a true (molecular) formula of C6H12O6. The empirical (reduced) formula is CH2O. Empirical Formula- Problem Solving Strategy Step 1 : Start with grams of each element Step 2: Convert to moles Step 3: Divided by the smallest # of moles Step 4: If needed, use a multiplier 54. What is the empirical formula of a compound that is 74.8% C and 25.2% H ? 55. What is the empirical formula of a compound that is 36.84% N and 63.16% O by mass? The actual or true formula for a compound is called the molecular formula. Molecular Formula- Problem Solving Strategy Step 1: Find the molar mass of the empirical formula Step 2: Divide the molecular weight of the true formula by the molecular weight of the empirical formula. Step 3: Multiply the empirical formula up by the answer from step 2. 56. A compound has an empirical formula of CH2 and a molecular weight of about 56 g/mol. What is the molecular formula of the compound? 57. A certain compound has an empirical formula of C2H4O and a molecular weight of about 44 g/mol. What is the molecular formula of this molecule? Chemical Reactions 58. Label each of the following: product, reactants, subscript, coefficient, yields H2 + Cl2 2 HCl 59. After a chemical reaction, the mass of products is _____ equal to the original mass of reactants. A. never B. sometimes C. always 60. Circle ALL of the following that are TRUE about what happens in ALL chemical reactions. A. B. C. D. Atoms are rearranged. More energy is released than absorbed Energy is absorbed to break the bonds of the reactants. Energy is released when the bonds of the products are formed. For questions #61-63, BALANCE the reaction using coefficients when necessary. CLASSIFY the reaction as one of the five types. 61. __ Zn + __ HNO3 __ Zn(NO3)2 + __ H2 A. decomposition B. Synthesis 62. D. single replacement E. double replacement __ CaCO3 + __ HCl __ CaCl2 + __ H2CO3 A. decomposition B. Synthesis 63. C. combustion C. combustion D. single replacement E. double replacement __ K2SO3 __ K2S + __ O2 A. decomposition B. Synthesis C. combustion D. single replacement E. double replacement Reaction Rates 64. Give one reason why increasing the concentration of reactants increases the reaction rate: more ____________________________ between reactant particles 65. List two reasons why a reaction rate increases with an increase in temperature. more ____________________________ between _______________________ more ____________________________ of greater _____________________________. 66. The _______________(smaller, larger) the particle size of a reactant the greater surface area available to react. This results in ________(more, fewer) collisions between reactant particles and a ______________ (faster, slower) reaction rate. reaction progress 67. In the diagram above of reactions B and C. Label each of the parts A, B, C, and D using the following terms…… product, reactant, catalyzed, uncatalyzed A: _____________________ B: _____________________________ reaction C: _____________________________ reaction D: _____________________ Which pathway has the lower activation energy, B or C? _____________ Which pathway corresponds to a faster reaction, B or C? ____________ Stoichiometry Ca(OH)2 + FeCl2 CaCl2 + Fe(OH)2 74 g 127 g 111 g ?g 68. According to the reaction above, how many grams of Fe(OH)2 should be formed? ______ g T or F ______ Because of the law of conservation of matter, the total mass of the reactants must equal the total mass of the products. Stoichiometry: Stoichiometry involves changing from one chemical to another and will always involve a balanced chemical equation (for the mole-mole step). Problem types: Mole- mole (1 step) Mole-mass or mass-mole (2 steps) Mass- mass (3 steps) Remember to always put the given unit in the bottom of step 1 and the desired unit in the top of the last step! Start this way and you really cannot go wrong. 69. 4 Na + O2 2 Na2O a) How many moles of sodium will react completely with 3.82 moles of oxygen (O2)? b) How many moles of Na2O can be produced from 13.5 mol Na? 70. C2H4 + 3 O2 2 CO2 + 2 H2O a) How many grams of C2H4 (28.06 g/mol) are needed to produce 66.7 grams of water? b) How many grams of O2 are needed to react with 2.56 g C2H4 (28.06 g/mol)? Kinetic-Molecular Theory and Gases 71. What happens to gas pressure if its volume is decreased? What happens to the volume of a gas if the pressure is increased? increase or decrease increase or decrease 72. What happens to the volume of a gas if the temperature is increased? increase or decrease What happens to the temperature of a gas if the volume is increased? increase or decrease Gas variables include P, V, T, and the amount of gas. 73. List 3 variables and how you would change them to increase the pressure of a gas. a) _________________________________________ b) _________________________________________ c) _________________________________________ 74. What does STP stand for? __________________________________________________ What are the values of STP? ___________ and ___________ For #75-78, you may refer to the following formulas and information: P1 V1 = P2 V2 T1 T2 K = oC + 273 1 atm = 760 mmHg = 101.3 kPa REMEMBER TO CONVERT TEMPERATURES TO KELVIN. 75. 2.00 L of a gas at 2.58 atm is compressed to a volume of 1.20 L. What is the pressure if the temperature is constant? 76. A gas at 25.0oC and 760 mmHg is cooled to 0.00oC. What is the pressure if the volume is held constant? 77. 5.00 L of a gas at –15.8oC and 745 mmHg is stored in a flexible container. What is the volume at STP? Solutions 78. Label each solution as saturated, unsaturated, or supersaturated based on the addition of solute: _______________ _______________ _______________ 79. Complete the phrase that describes the types of substances that will dissolve in each other: _______ dissolves _______. Therefore, polar solvents (like water) can dissolve ___________ solutes (like alcohols, sugars, ionic compounds, etc.). But nonpolar solutes (like fats, oils, hydrocarbons, etc.) will dissolve in _______________ solvents. For #80-81, you may use the following formulas: mol of solute M = Liter of solution . M 1V 1 = M 2V 2 80. What is the molarity of a solution containing 1.98 moles NaCl of solute in 775 mL of solution? 81. How many mL of a 0.150 M NaBr solution are needed to make 0.100 L of 0.0500 M NaBr? Acids and Bases 82. List 3 properties of acids: taste: ____________ litmus color: _______ ______________________________ List 3 properties of bases: taste: ____________ litmus color: _______ ______________________________ What property to acids and bases both have? _____________________________________________ For #83-85, you may use the following formulas: pH = –log[H+] pH + pOH = 14 MaVa = MbVb 83. Label each of the following as acidic (A), basic (B), or neutral (N) by writing the letter A, B, or N. a) hydrogen ion concentration of 1 x10-3 M _____ pH = ________ b) [H+] = 1 x10-9 M _____ pH = __________ c) [OH–] = 1 x10-8 M _____ pH = ___________ 84. Determine the pH of the following: 85. a) hydrogen-ion concentration of 1 x10–4 M ______ (no calculator needed) b) [H3O+] = 1.0 x10–7 M ______ (no calculator needed) c) 0.150 M hydronium ion ______ (use calculator) 10.0 mL of NaOH of unknown concentration is titrated by adding exactly 15.8 mL of 0.150 M HCl to completely neutralize the base. What was the concentration of NaOH? Before setting up the titration problem, write a balanced chemical equation for the neutralization reaction. KEY 1. a, b, g 2. 1. compound 3. a. F 4. a. heterogeneous mixture b. homogeneous mixture c. homogeneous mixture d. element (H2) e. element (Ag) f. compound (H2O) 2. mixture b. T c. T Mixtures- Physical 3. element 4. element d. T g. compound (NaCl) h. compound (CO2) i. compound (H2O) Compounds/Chemical Elements/No. Elements cannot be broken down 5. a. element b. compound 6. C 7. 10. C 11. endo- 12. An exothermic graph should start with high energy reactants and end with low energy products 13. released to exo- B 8. endo- A endo- warm up 9. exo- warm D exo- higher 14. An endothermic graph should start with low energy reactants and end with high energy products. absorbed from 15. cool down cool lower average= 3.32 g % error = (T-E)/T x 100 = (3.45 – 3.32)/ 3.45 x 100 = 3.7% error The result is accurate because the average (3.32 g) is close to the theoretical (3.45 g) with less than 5% error. The results are not precise because the measurements are not consistent and close to each other. Accuracy refers to the closeness of a result to the “true” value. Precision has to do with being able to repeat a measurement or result with consistency. 16. 6,550 cm 17. 0.0023 L 18. Gold (closest to measured density of 18.9 g/cm3) “equal to” b/c density does not change with the amount of a substance 19. C 20. B 21. D 22. Isotopes are different forms of the same element. The atomic number for isotopes is the same, but the isotopes will have different mass numbers (and thus each isotope will have a different number of neutrons). 23. D 24. A 14 C and 6C are examples of isotopes. 6 12 25. 357.49 g/mol 110.98 g/mole A mole represents the amount of matter in 6.02 x 1023 atoms, molecules or formula units. The mass of a mole , in grams, is called its molar mass. Avogadro’s number….. It is of course 6.02 x 1023 (every good chemistry student knows this!) 26. 2.71 x 1024 atoms 27. 0.0669 mol 28. An electron in an excited state is located at a higher energy level and must emit energy to fall back down to the ground state at a lower energy level. 29. Figure B b/c the electron went to a higher energy level (further from the nucleus) which requires more energy. Figure A b/c the electron went to a lower energy level (closer to the nucleus) which requires the release of energy. Figure B b/c the electron moves between the most energy levels. 30. 1 2 3 4 31. Argon (Ar) 32. Mg and Sr b/c they have the same number of valence electrons (2) and will react similarly 33. Atoms get SMALLER moving across a period, but the atomic radius INCREASES going down a group. Nitrogen (N) 5 6 7 Carbon (C) 8 Calcium (Ca) From this trend, we predict that atoms in the upper right hand corner of the periodic table (He and F) will be small. Fr, found in the lower left corner of the table, is the giant of the element world. largest (Li) smallest (Ne) Atoms get smaller left to right across a period as more protons are added pulling electrons closer without adding more electron energy levels. 34. K < Na < Ca < Mg (Remember, the big atoms have the low I. E values. Small atoms have high I.E.) 35. a. smallest b. highest c. highest d. most 36. transferred 37. An ionic bond is a chemical bond caused by electrostatic _attraction_ between __cations___ and __anions__ that is formed by __transferring__ electrons between atoms. Ionic bonds always from between __metals__ and __nonmetals_. 38. Na and F Mg and S K and O 39. each has a metal and a nonmetal element 40. Fe2O3 NaBr CuCl2 AlCl3 iron(III) oxide sodium bromide copper(II) chloride aluminum chloride 41. copper(II) oxide calcium sulfide magnesium iodide nickel(II) bromide 42. Atoms share electrons in covalent bonds to obtain a complete valence electron level (octet). 43. C 44. D 45. 46. C It takes more energy to overcome water’s especially strong intermolecular attractive forces CuO CaS MgI2 NiBr2 (hydrogen bonding) to separate the liquid molecules to the vapor phase. 47. carbon tetrachloride, disulfur trioxide, carbon disulfide 48. P4O5, CO2, CO 49. -ide 50. 51. 52. O2 has a double bond, NH3 will have 3 single bonds and one unshared e- pair, H2O has two single bonds and 2 unshared electron pairs, HCN contains a single bond and a triple bond. 53. 11.3 % C 54. CH4 55. N2O3 56. C4H8 57. C2H4O 58. reactants yields subscript products coefficient 59. C 60. A 61. 1, 2, 1, 1 D. single replacement 62. 1, 2, 1, 1 E. double replacement 63. 2, 2, 3 A. decomposition 64. collisions 65. more collisions between reactant particles C D more collisions of greater energy 66. smaller 67. A: more higher (faster) reactants B: uncatalyzed reaction C: catalyzed reaction D: products Reaction C has a lower activation energy caused by catalyst which allows the reaction to occur at a faster rate. 68. 90 g True 69. a) How many moles of sodium will react completely with 3.82 moles of oxygen (O2)? 3.82 mol O2 x (4 mol Na) = 15.3 mol Na (1 mol O2) b) How many moles of Na2O can be produced from 13.5 mol Na? 13.5 mol Na x (2 mol Na2O) = 6.75 mol Na2O (4 mol Na) 70. a) How many grams of C2H4 (28.06 g/mol) are needed to produce 66.7 grams of water? 66.7 g H2O x (1 mol H2O) x (1 mol C2H4) x (28.06 g C2H4) = 51.9 g C2H4 (18.02 g H2O) (2 mol H2O) (1 mol C2H4) b) How many grams of O2 are needed to react with 2.56 g C2H4 (28.06 g/mol)? 2.56 g C2H4 x (1 mol g C2H4) x (3 mol O2) x (32.00 g O2) = 8.76 g O2 (28.06 g C2H4) (1 mol C2H4) (1 mol O2) 71. increase decrease 72. increase increase 73. List 3 variables you could change to cause the pressure of a gas to increase. 74. a) increase the number of particles (add more gas) b) decrease the volume (compress it) c) increase the temperature Standard Temperature and Pressure 273 K (0oC) and 75. 4.30 atm 76. 696 mmHg (or 0.916 atm) 77. 5.20 L 78. unsaturated 79. like dissolves like. 1.00 atm (760 mmHg) supersaturated polar solvents can dissolve polar solutes saturated nonpolar solvents can dissolve nonpolar solutes 80. 2.55 M 81. 33.3 mL 82. taste: __sour___ litmus color: _red_ _single replacement reaction with metals to produce H2 gas__ taste: __bitter__ litmus color: _blue_ _feel slippery________________________________________ both are electrolytes (conduct electricity in solution) 83. a) A (pH = 3) b) B (pH = 9) c) A (pH = 6) 84. a) pH = 4 b) pH = 7 c) pH = 0.824 85. 0.237 M NaOH + HCl → NaCl + H2O ( NaOH and HCl have a 1:1 mole ratio.)