Weekly leaderboard. But you have to compare the Ka and Kb for these species before making a judgement! NH4Ff. Answered: Determine if the following salt is | bartleby Question: Will an aqueous solution of CH3NH3CN be acidic, basic or neutral? At 25C, 10 mL of aqueous sodium hydroxide solution is added to 100 mL of aqueous ethanoic (acetic) acid solution. Has anything like that creepy happened to you when someone you know account got hacked and knew someone else was using it? Why is acetic acid more acidic than phenol? We've added a "Necessary cookies only" option to the cookie consent popup. In certain experimental conditions . Remember, when certain soluble salts are dissolved in water the resulting solution is not neutral. Support your answer with calculations. Support your answer with calculations. Why is the compound 3,4-dihydroxy-3-cyclobutene-1,2-dione more acidic than acetic acid? Consider the following acids and bases: Ka (HCN) =6.2 x 10^-10; Kb (CH3NH3) = 4.4 x 10^-4. ch3nh3cn acid or base or neutral 15 6 . Calculate the pH after 41.9 mL of NaOH has been added. NH4Cl, NaClO4, Na2S, MgBr2, Ba(CH3CO2)2. Ka for acrylic acid is 5.6 105. a. First statement is correct. CH3NH3CN - basic g. NaNO2 - basic h. KOCl - basic 5. Challenge Problems 695 c. Calculate the pH of a 0.050 M solution of sodium acrylate (NaC3H3O2). We have learnt about three classes of substances: acids, bases and neutral substances. Chem 104 exam Flashcards | Quizlet Answer Save. What are the units used for the ideal gas law? Calculate the pH of each of the following solutions (4 points) (a) 0.12 M KNO2 . Decide if the solution is acidic, basic or neutral: Solution is acidic because [H +] > [OH-] Question 2. a.C5H5NHCLO4 b.NH4NO2 c.KOCL d.NH4OCL, Which of the following will be more soluble in an acidic solution than in pure water? So yes, it is a weak acid (NH4+) and weak base (NO2-). Pitt Faculty Diversity And Development. True: Adding more [CH3NH3+] to the initial buffer solution will decrease the pH. %PDF-1.5 % NaClO RbI CH3NH3CN Fe(ClO4)3 C2H5NH3Br. Choose an expert and meet online. If neutral, simply write only NR. The best answers are voted up and rise to the top, Not the answer you're looking for? One difficult aspect of acid-base chemistry is recognizing what types of species are present in solution, i.e., whether a species is a strong acid, strong base, weak acid, weak base or a neutral species. ch3nh3cn acid or base or neutral - darmoweszablonycanva.pl estas disculpada/o. Strong Acids and Strong Bases. This behavior of cations and anions as acids or bases depends on the strength of acid or base they are associated with. Ka(HCN) =6.2 x Consider 0.25 M solutions of the following salts. 1. . Fe(ClO4)3-Acid Acid - Base Properties of Amino Acids: Acidic Side Chains: If the side chain contains an acid functional group, the whole amino acid produces an acidic solution. . Ion that changes the p H Circle the correct option Basic Salt NaNO2 Acidic Neutral LiCIO4 Acidic Basic Neutral Acidic Neutral KC2H302 Li,S Mgl2 Basic Acidic Basic Neutral Acidic Basic Neutral NH,C Acidic Basic Neutral . We saw that what will be the nature of salt if the acid and base both are strong, and what will be the nature if one of them is strong and the other is weak. AP Chemistry Test Review (Pink Cards) 24 terms. 10-48. (a) pH = 8.0 (b) pH = 7.0 (c) pH = 3.5 (d) pH = 6.1 . So yes, it is a weak acid (NH4+) and weak base (NO2-). 5. Use MathJax to format equations. The following self acidic basically neutral for those air. neutral? Solutions with a pH value less than 7 are acidic in nature and the pH value of basic solutions is greater than 7. KClb. Because acidity and alkalinity relate to pH, they may also be known as pH indicators. no: NaOBr. SB:SA SB:WA WB:SA WB:WA. In chemistry, bases are substances that, in aqueous solution, are slippery to the touch, taste astringent, change the color of indicators (e.g., turn red litmus paper blue), react with acids to form salts, promote certain chemical reactions (base catalysis), accept protons from any proton donor, and/or contain completely or partially . MgCl2 is a generally considered to be a neutral salt.This compound can be formed from the reaction of Mg(OH)2 (a strong base) and HCl (a strong acid).Salt formed by combining strong acid and weak base are acidic in nature.MgCl2 is prepared by weak base Mg(OH)2 and HCl, Thus it is slightly acidic in nature. RbI. Acidity and basicity, proton concentration, the pH scale, and buffers. Consider the following questions about polyprotic acids and determine if each statement is true or false. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. Victor. the solution is neutral. Herein, is nh4cn neutral acidic or basic? ch3nh3cn acid or base or neutralgirondins bordeaux players. Behr Direct To Metal Paint Eggshell, Copy. a. NaNO 3. b. NaNO 2. c. C 5 H 5 NHClO 4. d. NH 4 NO 2. e. KOCl. 5 Answers There is no word like addressal. KH 2 PO 4 - acidic (H 2 PO 4-is amphiprotic, it can react as both an acid and a base. NaOH is strong base, HCl a strong acid, solution is neutral NH4Cl + HOH ==> NH4OH + HCl NH4OH (NH3 + HOH) is a weak base, HCl a strong acid, solution is acidic. CHAPTER 14 ACIDS AND BASES - Houston Community College State whether each of the following aqueous solutions would be acidic, basic, or neutral. Industrial Area: Lifting crane and old wagon parts, how to make hot tamales with aluminum foil, medial meniscal extrusion: detection, evaluation and clinical implications, mobile homes for rent in osceola county, fl, the reserve club aiken, sc membership cost. C6H5NH3+, conjugate base is a weak base, therefore it is potentially acidic NO2-, conjugate acid is a weak acid, therefore the salt is also potentially basic However, since the Ka > Kb, the solution must be acidic So it has both nature acidic on basic in its constituent, it will act as a neutral soul. H 3 O +. Chemistry 830,000. The pH of the aqueous solution is 8-9.5. To tell if CH3COONa (Sodium acetate) forms an acidic, basic (alkaline), or neutral solution we can use these three simple rules along with the neutralization reaction that formed CH3COONa .First we need to figure out the acid and base that were neutralized to form Sodium acetate. Chinese Atv Reviews, Your email address will not be published. We have the K s of the con trick it acids and for the K A vise for week and says . Is sodium nitrate acidic basic or neutral? Home. Therefore, the following species would be present: C H X 3 C H X 2 N H X 3 X +. A. acidic B. basic N. neutral - e-eduanswers.com All of these salts will fully dissociate in water. Chemistry questions and answers. 10^-10; Kb (CH3NH3) = 4.4 x 10^-4. My sister asked me what acids and bases are, this is what I told her. Is CH3NH3CN an acid or base? - Answers Normally, an amino acid produces a nearly neutral solution since the acid group and the basic amine group on the root amino acid neutralize each other in the zwitterion. To tell if KNO2 (Postassium Nitite) forms an acidic, basic (alkaline), or neutral solution we can use these three simple rules along with the neutralization . About this tutor About this tutor I was skimming through the questions and ran across this one - this is What is. How many moles of NaClO were originally added? Solved Will an aqueous solution of CH3NH3CN be acidic, basic | Chegg.com Solution z has a pH 4.0 units higher than that of solution x. calculate the ration of [H3O+] between solutions x&y and between x&z. Add your answer and earn points. The solution should be slightly acidic. Depending on the composition of the salt (the ions which it is made up of) the solution will be either acidic or basic. NH 4 + ions are acidic (conjugate acid of the weak base NH 3 ). If you are having trouble with Chemistry, Organic, Physics, Calculus, or Statistics, we got your back! bonjourr bonjourr What is CH3NH3CI my dude -3-New questions in Chemistry. Hu Hot Menu, will the following solutions be acidic, neutral, or basic? The Ka for NH4+ can be found by Kw/(Kb for NH3) and the Kb for NO2- can be found by Kw/(Ka for HNO2). HONH3 NaNO2 Salt Solve each of the following. The overall salt does not donate protons, the CH3NH3+ ion does (to form H3O+) when the salt is dissociated in water. See Appendix 5 for K_{\text {a values. }} and A when the acid ionizes in water; Figure 1 lists several strong acids. A 5-kg box is being lifted upward at a constant velocity of 2m/s2 \mathrm{~m} / \mathrm{s}2m/s by a force equal to the weight of the box. acidic NH4CN is acidic, basic or neutral? Using equation ( 2), we know that C H X 3 C H X 2 N H X 3 X + will react with water reaching an acidic equilibrium. CH3NH3CN Thanks!! Decide if each of the following is a major or minor species in the solution. ch3nh3cn acid or base or neutral. This answer is: Study guides. Where Ka is the ionization constant of the acid form of the pair, Kb is the ionization constant for the base form of the pair, and Kw is the ionization constant for water. Homework Acid/Base VII Acid/Base VII - Problem 2 of 2 a. ammonium bicarbonate b. sodium dihydrog Why is $\ce{CH3CH2NH3Cl}$ acidic? Solution Can be Acidic, Basic, or Neutral. If you preorder a special airline meal (e.g. And since sodium nitra. CHNHCyanide is a salt of weak acid hydrogen cyanide and weak base CHNHOH, so the resultant solution of the salt is neutral in nature. $\ce{CH3CH2NH3Cl}$ is acidic because it is formed from a strong acid ($\ce{HCl}$) and a weak base ($\ce{CH3CH2NH2}$). ( 3 point) For each of the following salts, identify the ion that will influence the pH of its aqueous solution (if any) and classify the solution as acidic, basic or neutral. It is probably a bit alkaline in solution. 2015 Yz250 For Sale, The cation is the conjugate acid of a weak base. To know more acidity or basicity, visit the below link: brainly.com/question/172153 Still stuck? For the next three problems, consider 1.0 L of a solution which is 0.55 M HF and 0.2 M NaF (Ka for HF = 7.2 x 10-4). Esposa del rey. Are the solutions of the following salts acidic, basic, or neutral ? Elaborated Notice that this compound is ionic, comprising $\ce {CH3CH2NH3+}$ cation and $\ce {Cl-}$ anion. 2014-10-24 15:17:31. Support your answer with calculations. Determine whether each of the following salts will form a solution that is acidic, basic, or pH-neutral. Water is the base that reacts with the acid HA, A is the conjugate base of the acid HA, and the hydronium ion is the conjugate acid of water. Post author: Post published: June 8, 2022 Post category: female personal trainers near me Post comments: pete quaife height pete quaife height ch3nh3cn acid or base or neutral - modularmusica.com And we have the K A values and K A B values and tables 14.2 and 14.3. Ka(HCN) =6.2 x 10^-10; Kb (CH3NH3) = 4.4 x 10^-4. If [CH3NH3+] <[CH3NH2], then pH is larger than the pKa value. How can you do a cross product on a TI-89 calculator? Rita Cosby Voice, answered 03/19/17, Praxis Certified Chemistry Tutor and Professor. Acidic and Basic Salt Solutions. Its a salt of weak base and strong acid so on hydrolysis it forms acidic solution. Determine whether each of the following salts will form a solution False: A solution consisting of 0.1 M CH3NH3Cl and 0.1 M CH3NH2 would be a more effective buffer than one containing 1.5 M CH3NH3Cl and 1.5 M CH3NH2 none anion cation cation and anion =7 >7 <7 < 7 if Kb 7 if Kb > Ka Predict whether aqueous solutions of the following salts are acidic, basic or neutral: 1. pic. Favourite answer. a. KBr b. NaNO2 c. CH3NH3Cl d. Na2CO3. 14 terms. . basic: Sr(OC6H5)2 Making statements based on opinion; back them up with references or personal experience. Calculate the pH after 0.10 mol of HCl has been added to the original solution. C2H5NH3Br. It will have no sharp endpoint upon titration. Hence, appropriate differentiation was done above. Sciences, Culinary Arts and Personal Become a Study.com member to unlock this Ammonium nitrite is the salt of quite a weak acid and a weakish base. H 2 PO 4-+ H 2 O X H 3 O + + HPO 4 2-K a = K a2 for H 3 PO 4 = 6.2 x 10-8 H 2 PO 4-+ H 2 O X H 3 PO 4 + OH-Since K a > K b, the solution will be acidic. Used Washing Machines Under 200, Wrap Around Mortgage Contract Form, Survey SOMEONE ASKED Lewis dot structure for cas HERE THE ANSWERS What is the straw hat law and why did some amish guy use it against a cop when he didn't pull his buggy over? ch3nh3cn acid or base or neutral. The overall salt does not donate protons, the CH3NH3+ ion does (to form H3O+) when the salt is dissociated in water. Ka of HClO is 3.0 10. See the answer See the answer See the answer done loading. CH3NH3CN basic, acidic, or neutral? - AnswerData Which type(s) of rock is (are) made from previously existing rock? On the other hand, soluble salts that contain cations derived from weak bases form solutions that are acidic. Shake the tube until all the solid dissolves completely. Is the solution acidic, basic or neutral? $\ce {CH3CH2NH3Cl}$ is acidic because it is formed from a strong acid ($\ce {HCl}$) and a weak base ($\ce {CH3CH2NH2}$). How do I determine the molecular shape of a molecule? The relationship between Ka and Kb for any conjugate acid-base pairs is: Calculate the pH of the glacial acetic acid and the solution you prepared in step 1. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Naclo4 Acid Or Base Or Neutral - apkcara.com (a) What is the power input of the force? It is probably a bit alkaline in solution. Determine if the following salt is neutral, acidic or basic. Berkeley County School District, Calculate the pH after 0.10 mol of HCl has been added to the original solution. Is CH3NH3+ an acid or base? - Studybuff 7. The Kb values for ammonia and methylamine are 1.8 x 10-5 and 4.4 x 10-4 respectively. When B accepts a proton, the central atom goes from having 3 bonded hydrogens . 2 years ago. false: conjugate bases of weak acids will be acidic, Prelecture_assignments acid_base_VI_prelect. Pieza del juego de ajedrez,la ms importante despus del rey: la reina puede moverse como cualquiera de las dems piezas,excepto el caballo. Unfortunately, your shopping bag is empty. KCl-Neutral A) Sr(NO3)2 B) NH4C2H3O2 C) CH3NH3Cl D) C6H5NH3ClO2 E) NH4F F) CH3NH3CN A) Sr(NO3)2 B) NH4C2H3O2 C) CH3NH3Cl D) C6H5NH3ClO2 E) NH4F F) CH3NH3CN weak acid. To neutalize an acid with a base you must put the base in the acid, that will give the substance pH of 7 which is neutral. Acids and Bases. around the world. CHNHCyanide is a salt of weak acid hydrogen cyanide and weak base CHNHOH, so the resultant solution of the salt is neutral in nature. Acidity of alcohols and basicity of amines. b. Identify the nature of the salts in an aqueous solution. The relevant Ka and Kb values are found in Tables 14.2 and 14.3. a. NaNO3 c. C5H5NHClO4 e. . a. Record your pH value to 2 decimal places. paul stookey obituary 2021. ch3nh3cn acid or base or neutral. CH3NH3CN basic, acidic, or neutral? Se escribe reina. Most questions answered within 4 hours. H2NNH2. neutral: NaCl ch3nh3cn acid or base or neutral - creditsolutionexperts.com For those that are not neutral, write a balanced chemical equation for the reactions causing the solution to be acidic or basic. This is the best answer based on feedback and ratings. Topblogtenz.com DA: 15 PA: 50 MOZ . Refer to Section 10-8. Calculate the pH after 0.20 mol of NaOH has been added to the original buffer solution. 21. Which is the stronger acid, NH4+ or CH3NH3+ ? To subscribe to this RSS feed, copy and paste this URL into your RSS reader. For Free. Determine if each salt will form a solution that is acidic, basic, or pH-neutral. hbbd```b``; Services, What is Salt Hydrolysis? Using equation $(2)$, we know that $\ce{CH3CH2NH3+}$ will react with water reaching an acidic equilibrium. Using Kolmogorov complexity to measure difficulty of problems? This equation is used to find either Ka or Kb when the other is known. This is because water sits at a pH of 7 and we do most of our chemistry in water. Chemistry. Follow 3. How can this new ban on drag possibly be considered constitutional? How did erupting volcanoes contribute to the formation of oceans? A solution consisting of 0.1 M CH3NH3Cl and 0.1 M CH3NH2 would be a more effective buffer than one containing 1.5 M CH3NH3Cl and 1.5 M CH3NH2 If [CH3NH3+] = [CH3NH2], then pH = 7.00. CN - ions are basic (conjugate base of the weak acid HCN). Advantage Solutions Glassdoor, pH is a measure of the concentration of hydrogen ions (H+) in a solution. Watch Queue Queue. Which combination of the following substances would make the best choice to prepare a pH=6.0 buffer solution? Let's investigate the pH of salts dissolved in water. 97% of Numerade students report better grades. What is the electron configuration of Gallium in its excited state? The equation for KNO2 is:HNO2 + KOH = KNO2 + H2OIt is also useful to have memorized the common strong acids and bases to determine whether KNO2 acts as an acid or base in water (or if it forms a neutral solution).Strong acids: HCl, H2SO4, HNO3, HBr, HI, HClO4Weak acids: HF, CH3COOH, H2CO3, H3PO4, HNO2, H2SO3Strong Bases: LiOH, NaOH, KOH, Ca(OH)2, Sr(OH)2, Ba(OH)2Weak Bases: NH3, NH4OHNote that we are talking about whether KNO2 is an acid, base, or neutral when dissolved in water.- Salts of strong bases and strong acids: pH will remain neutral at 7.- Salts of weak bases and strong acids: pH less than 7 (acidic).- Salts from strong bases and weak acids: pH greater than 7 (alkaline).Based on these rules, the solution of KNO2 dissolved in water is Basic.For polyprotic acids (e.g. If pH > 7, then the solution is basic. Calculate the pH of a 0.87 M solution of C6H5NH3NO3 (Kb for C6H5NH2 = 3.8 x 10-10). Assume no volume change on addition of NaOH. Best Answer. Chemistry Stack Exchange is a question and answer site for scientists, academics, teachers, and students in the field of chemistry. Jun 23. ch3nh3cn acid or base or neutralburning off yarra ranges. The ions from KCl derive from a strong acid (HCl) and a strong base (KOH).Therefore, neither ion will affect the acidity of the solution, so KCl is a neutral salt.Although the K + ion derives from a strong base (KOH), the NO 2 ion derives from a weak acid (HNO 2). Will an aqueous solution of CH3NH3CN be acidic, basic or Is Sr(OH)2, Strontium Hydroxide, an Acid, Base, or Neutral? NaClO. 10^-10; Kb (CH3NH3) = 4.4 x 10^-4. ch3nh3cn acid or base or neutral - prostarsolares.com What is the conjugate base of H2NNH3+? This problem has been solved! Click to see full answer. Is the solution acidic, basic or neutral? Chris needs to make 500 L of a 35% acidic solution. State whether each of the following aqueous solutions would be acidic, basic, or neutral. Those that are made from strong acids and strong bases will be neutral in water soln (have pH = 7 in water.) Why is sodium sulfate neutral while its conjugate acid is weak? Raise to minus 4 point. 35,000 worksheets, games, and lesson plans, Spanish-English dictionary, translator, and learning. The pH of the resulting solution is 3.4. Fe(ClO4)3. Base Acid Conjugate Conjugate Acid of B Base of HX B is the proton acceptor (the base) and HX is the proton donor (the acid). False: If HCl were added to the initial buffer solution, then the [CH3NH3+] would decrease. No mistakes. 14 terms. Adding more [CH3NH3+] to the initial buffer solution will decrease the pH. Isabelle_Boynton. C6H5NH3ClO2 E) NH4F F) CH3NH3CN acid-base; A) CH3NH3+ is a weak acid; CN- is a weak base; So the solutionis view the full answer CH3NH3CN; in which the strength of an acid,or a base in a liquid solution is measured.the ph scale is a series ; Is HCO3- an acid or base. saragillchem. Buffers are important, especially in biological systems. Assume 2 significant figures in all of the given concentrations so that you should calculate all of the following pH values to two decimal places. What is the pH of NaI? 3. To tell if KNO2 (Postassium Nitite) forms an acidic, basic (alkaline), or neutral solution we can use these three simple rules along with the neutralization . ch3nh3cn acid or base or neutral - jmcaa.com Salts are made from acids and bases. Support your answer with calculations. for those that are not neutral, write balanced equations for the reactions causing the solution to be acidic or basic. Because of this, when an acid is dissolved in water, the balance between hydrogen ions and hydroxide ions is shifted. ch3nh3cn acid or base or neutral - na99jo.com Classify the following compounds as having covalent or ionic bonds.? 5538 0 obj <>stream Services, What is Salt Hydrolysis? A salt is the product of an acid reacting with a base in the Arrhenius theory. Water accepts a proton from vinegar. 4. 2. (6 points) 3. More Ionic Salts Solutions Post your own question here.. b. HC7H5O2. 5505 0 obj <>/Filter/FlateDecode/ID[<5F593A48C7A8C842808F88DD110C0DBF><974ABC930B966D43A1E06811416B86E6>]/Index[5484 55]/Info 5483 0 R/Length 104/Prev 851319/Root 5485 0 R/Size 5539/Type/XRef/W[1 3 1]>>stream Ka for NH4+ is 1.00 x 10^-14 / 1.8 x 10^-5 =5.6 x 10^-10, Kb for NO2- is 1.00 x 10^-14 /4.5 x 10^-4 = 2.2 x 10^-11. This is known as the \(pH\) scale. 156. Do roots of these polynomials approach the negative of the Euler-Mascheroni constant? Linear Algebra - Linear transformation question. And the nature depends on the nature of the parent acid and base. HCO2H Ka=1.8x10-4 HONH2 Kb=1.1x10-8 We reviewed their content and use your feedback to keep the quality high. ch3nh3cn acid or base or neutral - justripschicken.com The solution is neither acidic or basic. We define acids as having a pH less than 7 and bases as having a pH above 7. Of course, if you have any bottles of Universal Indicator lying around, use them. I also have for the K B for the K B values of week basis. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. a. KCl b. NH4C2H3O2 c. CH3NH3Cl d. KF e. NH4F f. CH3NH3CN Thanks! CH3NH3Cld. Add 2.0 mL of 1.0 M NaOH to the tube and shake for 30 seconds. 99. yes: HONH2 Help, not sure if. Salt solutions are acidic because of hydrolysis. Acid-base reactions are called neutralization reactions because the reaction of an acid with a base generally produces a salt with little or no acid-base character and, in many cases, water. 23 June 2022; what is personal narrative . 21. CH3NH3Cl is an ionic compound, consisting of CH3NH3+ and Cl- ions. C H X 3 C H X 2 N H X 2. MathJax reference. All rights reserved. For those that are not neutral, write balanced chemical equations for the reactions causing the solution to be acidic or basic. KFe. One must compare K a and K b for H 2 PO 4-.) neutral? 24 Semanas De Embarazo En Meses, Therefore the acid strength here is slightly higher than the base strength. I've tried submitting the ones that are insoluble in water and it was wrong. Chem 2 chapter 17 (& end of 16) 66 terms. Concentrated sulphuric acid should not be used while preparing hydrogen gas in laboratory. What is ecotourism and how can it help protect wildlife? Neutralization of any strong acid with a strong base always gives a neutral salt. Determine if the salt NH4NO2 is acidic, basic or neutral. Sr2 is acidic. Um, thus so a decision. answered 03/31/17, Master's in Chemistry with 20+ Years of Teaching/Tutoring Experience, Sreedevi Y. Calculate [OH] for each of the following solutions, and indicate whether the solution is acidic, basic, or neutral. As such, NaNO3 is neither an acid nor a base. AcidsBases Sour Bitter Also referred to as alkali H2O solutions feel slippery. 2. If [CH3NH3+] < [CH3NH2], then the [H+] is larger than the Ka value. The salt in which the cationic part is the conjugate acid of a weak base then . SrF. 5.0 (384) Master's in Chemistry with 20+ Years of Teaching/Tutoring Experience. Not neutral, right bounds questions for the reaction causing the acidic or basic. Sr(ClO4)2 ,NaCl,Sr(OC6H5)2 ,C5H5NHBr ,NH4Cl ,NaCN, neutral: Sr(ClO4)2 Are the solutions of the following salts acidic, basic, or neutral ? It only takes a minute to sign up. For the next three problems, consider 1.0 L of a solution which is 0.55 M HC2H3O2 and 0.2 M NaC2H3O2 (Ka for HC2H3O2 = 1.8 x 10-5).