* Compiled from Appendix 5 Chem 1A, B, C Lab Manual and Zumdahl 6th Ed. I need to find the pH of a solution containing 50 grams of Na3PO4. Abase ionization constant (Kb)is the equilibrium constant for the ionization of a base. What is the freezing point of a solution that contains 0.5 moles of Nal = 141.98 g/mol) that has been dissolved in a 250 mL volumetric flask and diluted to the mark. In this video we will describe the equation Na3PO4 + H2O and write what happens when Na3PO4 is dissolved in water.When Na3PO4 is dissolved in H2O (water) it will dissociate (dissolve) into Na + and PO4 3- ions. im sorry to be a bit slow on this, but why couldnt you use k1 for this problem? Trisodium phosphate was at one time extensively used in formulations for a variety of consumer-grade soaps and detergents, and the most common use for trisodium phosphate has been in cleaning agents. Nov 23, 2010. They are all defined in the help file accompanying BATE. Starts Today. Na+ = Sodium Mg2+ = Magnesium Al3+ = Aluminum2.Find the polyatomic ion on the Common Ion Table and write the name.Note: It is possible to have two polyatomic ions such as NH4NO3. If 0.50 mole of BaCl2 is mixed with 0.20 mole of Na3PO4 , the maximum number of moles of Ba3 (PO4)2 that can be formed is . In this video we will describe the equation Na3PO4 + H2O and write what happens when Na3PO4 is dissolved in water.When Na3PO4 is dissolved in H2O (water) it . Manakah diantara berikut titik beku yang paling tinggi How To Remove Scratches From Chrome Plating. For reference or additional information, please contact websupport@aatbio.com, Click here to see all available distributors, https://www.aatbio.com/data-sets/pka-and-pkb-reference-table, (nitrilotris(methylene))triphosphonic Acid, 1(2h)-Pyrimidinecarboxamide, 5-Fluoro-3,4-Dichlo, 1(2h)-Pyrimidinecarboxamide, 5-Fluoro-3,4-Dihydr. Acid pH = Base Hydrolysis Reaction Ka Kb 2.4E-02 pka E pKb Calculations: Potassium Nitrite Calculate the pH of 0.10 M KNO2 solution. How to calculate pH of solution made of H3PO4 and Na3PO4? H I think that is what you call it. Architektw 1405-270 MarkiPoland. Requested URL: byjus.com/chemistry/sodium-phosphate/, User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/103.0.5060.114 Safari/537.36 Edg/103.0.1264.62. It's possible your card provider is preventing 14.7: Conjugate Acid-Base Pairs and pH - Chemistry LibreTexts Calculate the pH of 0.5 M Na3PO4 in aqueous solution ? Potassium Nitrite Calculate the pH of 0.10 M KNO2 solution. pKa: A quantitative measure of the strength of an acid in solution; a weak acid has a pKa value in the approximate range 2 to 12 in water and a strong acid has a pKa value of less than about 2. This is a recorded trial for students who missed the last live session. Molar mass of Na3PO4 = 163.940671 g/mol. Diprotic and Triprotic Acids and Bases - Purdue University Calculate the pH of a solution of 0.100 M Na3PO4. For this reason,Kavalues are generally reported for weak acids only. a: Na3PO4 and AgNO3 b: K2SO4 and Na2CO3 C: Pb(NO3)2 and Na2CO3 d: BaCl2 and KOH. 100% (1 rating) ka Kb=10-14/Ka Phosphori . The high-temperature phases of sodium orthophosphate, HT-Na3PO4, and of the solid solutions (Na2SO4)x(Na3PO4)1-x are characterized by their plastic crystalline state with dynamically disordered PO43- and SO42- anions and a remarkably high cation conductivity. -3.7^@"C" Your strategy here will be to determine the van't Hoff factor for sodium iodide, "NaI" calculate the molality of the solution calculate the freezing-point depression of the solution The idea is that the freezing point of a solution is lower than the freezing point of the pure solvent, which for water is 0^@"C" at normal pressure. Unless otherwise stated, pKa and pKb was measured at STP. Aweak acidis an acid that ionizes only slightly in an aqueous solution. Molecular weight calculation: 22.98977*3 + 30.973761 + 15.9994*4. Polyprotic acids are those with more than one acidic proton. Molecular Weight/ Molar Mass. How many grams of Na3PO4 will be needed to produce 450 mL of a solution that has a concentration of Na+ ions of 0.700 M; A scientist wants to make a solution of tribasic sodium phosphate,Na3PO4 , for a laboratory experiment. D The overall dissolution of LiCl is exothermic; this is indicated by the temperature of the water rising. 31 164 100 = 18.9%P. CHEM 1172 EXAM 3 [CH 15 16 + 17] Flashcards | Quizlet a.h2co3b.h2oc.h2po4-d.po43-_ Calculate the pH of a 0.0798 M H3PO4 solution. Products sold as TSP substitutes, containing soda ash and zeolites, are promoted as direct substitutes. Solution for What is the percent ionization of HNNH in a solution with a concentration of a 0.580 M? Boiling Point. PDF Chapter 17 (Kb > 1, pKb < 1). [citation needed], Although it is still the active ingredient in some toilet bowl-cleaning tablets, TSP is generally not recommended for cleaning bathrooms because it can stain metal fixtures and can damage grout. pKa and pKb Reference Table | AAT Bioquest [citation needed] This mixture is particularly effective for removing mildew, but is less effective at removing mold. As with acids, bases can either be strong or weak, depending on their extent of ionization. 11.22 b. Kb for PO4 3- + H2O --> HPO4 2- + OH - is 4.5 X 10 3 A) 2.2 B) 1.82 C) 11.8 D) 12.2 a. Trisodium phosphate has gained a following as a nutritional supplement that can improve certain parameters of exercise performance. Molecular weight of Na3PO4 - Convert Units 'days' : 'day' }}, {{ nextFTS.remaining.months }} Click hereto get an answer to your question What is the pOH of a 0.5 M Na3PO4 solution ? Acids. the boiling point of the NaCl solution will be greater than the boiling point of pure water. JavaScript is disabled. Done on a Dell Dimension laptop computer with a Wacom digital tablet (Bamboo). {{ nextFTS.remaining.months > 1 ? You'll get a detailed solution from a subject matter expert that helps you learn core concepts. BPP Marcin Borkowskiul. Starts Today, By clicking Sign up, I agree to Jack Westin's. Weak acids with relatively higherKavalues are stronger than acids with relatively lowerKavalues. Due to high demand and limited spots there is a waiting list. What is the pKa value for sodium phosphate? - Answers Step 2: Solve. A weak acid has a pKa value in the approximate range of -2 to 12 in water. So, no basic action either. Na3PO4 ==> 3Na^+ + PO4^-3. you must have since you knew your 5 was wrong, right? Weak Base Calculations Sodium Phosphate Conjugate Calculate the pH of 0.10 M Na3PO4 solution. The cation is Na^+ (it has a charge of +1) and there are three of them. christopher clarke missing; what is walter mittys fourth daydream; June 8, 2022 kb of na3po4 On the contrary inorganic bases - like NaOH, KOH, LiOH, Ca(OH)2 - increase pH dissociating. It is a white, granular or crystalline solid, highly soluble in water, producing an alkaline solution. 4 Ka=[H+][Al(OH)+2]/[Al+3] operating systems: XP, Vista, 7, 8, 10 single user license price: 24.95 - approximately $33 Buy Now! double check my worki just did this on a napkin and wolfram haha you're lucky i'm bored out of my mind at workhaven't typed up a solution like that in a long time Find the molarity first. kb of na3po4 - ASE How to Write the Name for Na3PO4 - YouTube {{ nextFTS.remaining.months }} Therefore, since the freezing point decreases by 24.0C, the freezing point of the solution is -24.0C. The acid equilibrium problems discussed so far have focused on a family of compounds known as monoprotic acids.Each of these acids has a single H + ion, or proton, it can donate when it acts as a Brnsted acid. FOIA. pH = Conjugate Acid Base Hydrolysis Reaction Kb c pka E pKb 10.66 Calculations: 58 D) All of the above. Screen capture done with Camtasia Studio 4.0. The acid dissociation constant (Ka) is a quantitative measure of the strength of an acid in solution while the base dissociation constant (Kb) is a measure of basicitythe base's general strength. 'days' : 'day' }} Table of Acids with Ka and pKa Values* CLAS * Compiled . where: T is the change in boiling point of the solvent, Kb is the molal boiling point elevation constant, and. Because strong acids are essentially 100% ionized, the concentration of the acid in the denominator is nearly zero and theKavalue approaches infinity. CHEM 1412. Review for Test 1 (chapter 13, 14, 15). Ky75 Na Write the balanced, complete, and net ionic equations for each precipitation reaction. The (aq) shows that they are aqueous dissolved in water.The equation for Na3PO4 ( Sodium phosphate and H2O sometimes isnt considered a chemical reaction since it is easy to change the Na + and PO4 3- back to Na3PO4 (just let the H2O evaporate). pH = Conjugate Acid Base Hydrolysis Reaction Kb c pka E pKb 10.66 Calculations: 58 At the same time, the Na3PO4 is a very different substance than Na + and PO4 3-.If you need to know how to balance chemical reactions, see my complete tutorial on balancing all types of chemical equations:Balancing Equations in 5 Easy Steps: https://youtu.be/zmdxMlb88FsMore Practice Balancing: https://youtu.be/Qci7hiBy7EQDrawing/writing done in InkScape. Rock - if you dont mind me asking what was your DAT score? Diprotic Acids. Na 3 PO 4. Chem: Acid & Base Equilibria Dynamic Study Module 8600 Rockville Pike, Bethesda, MD, 20894 USA. What Are The Ka And Kb Values For .1M Na2HPO4, NaH2PO4, And Na3PO4? Ka the acid dissociation constant and Kb the base dissociation constant are measures of the extend of dissociation of a weak acid or base in equilibrium. Click here to review boiling of pure liquids. Aweak baseis a base that ionizes only slightly in an aqueous solution. It is considered the solvent in these reactions, so the concentration stays essentially constant. Osmosis is the flow of a solvent into a solution through a semipermeable membrane. Note the interface between liquid water (below) and water vapor (above). . 'Starts Today' : 'remaining' }} asked Sep 28, 2022 in Chemistry by . pH calculator program - Base Acid Titration and Equilibria - dissociation constants pKa and pKb. What is the dissociation of Na3PO4? - Answers (K. = 7.5 x 10-3, Ka, = 6.2 x 10-8, K, = 4 x 10-13) What is the poth, 0.5 m Na solution Paperport your answer a: Depending on the source pKa for HCl is given as -3, -4 or even -7. View the full answer. Recently Asked Questions (1.0000x10^1) mL aliquots of a phosphoric acid solution with an unknown concentration is titrated with some (2.99x10^-1) mol/L sodium hydroxide solution.The; A solution turnsmethyl redred andbromocresol greengreen.What is a possible pH of the solution? Kb and Ka are also related through the ion constant for water, Kw, by the relationship Kw = Kb x Kb=a. Dissociation can be also described by overall constants, as well as base dissociation constants or protonation constants. A) Strong acid vs. strong base. Assume no volume change upon the addition of base. Solution: Osmosis and osmotic pressure are related. E) None of the above. {{ nextFTS.remaining.days > 1 ? C) 9. B) Strong acid vs. weak base. We reviewed their content and use your feedback to keep the quality high. Jawaban - Manakah diantara berikut titik beku yang paling tinggi nh4c1 0,1 m na3po4 0,1m al2(so) 0,1m co(nh2)2 0,1m - jawaban-sekolah.com I wish I had you as a personal tutor. National Library of Medicine. Given the acid constant for a weak acid . Calculate the pH of the solution containing 3.875g of Na 2 HPO 4 (MW. Step 3: Think about your result. Dissociation: the process by which compounds split into smaller constituent molecules, usually reversibly. HHS Vulnerability Disclosure. Solved What are the Ka and Kb values for .1M Na2HPO4, - Chegg (Ka=6.2x10^-10) is quite lower than the the Kb of NH4OH (Kb=1.8x10^-5). Is Na3PO4 acidic, basic, or neutral? - ECHEMI A lower pKb value indicates a stronger base. Then, calculate the molality of the solution. {{ nextFTS.remaining.days > 1 ? You can create your own Flashcards and upload decks E) 8. What is the pH of a 0.05 M solution of formic acid? (Ka = 1.8 10^-4) More. Please contact your card provider or customer support. As for pKb values of strong bases - NaOH, KOH, LiOH, Ca(OH)2 - pleas read the explanation in our FAQ section. (Kb > 1, pKb < 1). A scientist wants to make a solution of tribasic sodium phosphate,Na3PO4 , for a laboratory experiment. In this video we'll write the correct name for Na3PO4.To write the name for Na3PO4 well use the Periodic Table and follow some simple rules. : A quantitative measure of the strength of an acid in solution; a weak acid has a pKa value in the approximate range 2 to 12 in water and a strong acid has a pKa value of less than about 2. Since HT-Na3PO4 possesses a fully occupied cation sublattice (no vacancies), it has been proposed that cation transport and anion . Higher T will have a higher boiling point. This compound is also known as Trisodium Phosphate. pH = Conjugate Acid Base Hydrolysis Reaction Kb c pka E pKb 10.66 Calculations: 58 Table 2. nKa Values / Acid . Phosphoric acid is a triprotic acid, ionizing in the following sequential steps: Kal 7.11 x 10-3 Ko= 6.34 x 10-8 Kg = 4.22 x 10-13 What is the value of Kb for the base sodium phosphate (Na3PO4)? Given that HPO is a triprotic acid for which Ka1 = 7.2 10, Ka2 = 6.3 10 and Ka3 = 4.2 10, the Kb for HPO is 1.6 10. Answer to: Consider an aqueous 1.00 m solution of Na3PO4, a compound with useful detergent properties (kb = 0.51 C m-1). in these problems, being on the wrong side of neutral is the red flag that you picked the wrong direction (gaining/losing a proton). Now consider 1 mole of N a3P O4 which has a mass of 164g: 3 23 = 69g is sodium, 31g is phosphorous, 4 16 = 64g is oxygen. In this case find and write both names as found on the Common Ion Table.-----------------------------For a complete tutorial on naming and formula writing for compounds, like Sodium phosphate and more, visit:http://www.breslyn.org/chemistry/namingDrawing/writing done in InkScape. Answered: What is the percent ionization of | bartleby Sodium Phosphate. If 0.50 mole of BaCl2 is mixed with 0.20 mole of Na3PO4 , the maximum number of moles of Ba3 (PO4)2 that can be formed is . What is the osmotic pressure of a solution prepared by adding 13.65 g of sucrose (C 12 H 22 O 11) to enough water to make 250 mL of solution . Many compounds of pharmaceutical interest are formulated in sodium phosphate buffers. Besides, difference between pKa=-1 and pKa=-10 starts to influence calculation results for the solutions with very high ionic strengths, such calculations are dubious in any case. 2. Ky75, Page 5 24. Sodium Phosphate (Na3PO4) - Molecular Mass, Structure, Properties and Uses For example: CH3COOH pKa=4.76 c=0.1 HCl pKa=-10 c=0.1 Case 2. Acid pH = Base Hydrolysis Reaction Ka Kb 2.4E-02 pka E pKb Calculations: So we start with 0.090 mol of both NH4 + and NH 3.After complete reaction with 0.0010 mol NaOH the resulting amounts of each are: 0.090 0.0010 = 0.089 mol NH4 0.090 + 0.0010 = 0.091 mol NH3 To use Henderson-Hasselbalch equation we need to know the pKa value. TSP is used as a cleaning agent, builder, lubricant, food additive, stain remover, and degreaser. What is the percent CsCl by mass in a 0.711 M CsCl solution that has a density of 1.091 31P and 23Na Solid-State NMR Studies of Cation Dynamics in HT-Sodium For H3PO4, Ka1 = 7.5 103, Ka2 = 6.2 108, and Ka3 = 4.2 1013., What is the pH of a solution that has 0.250 M HF and 0.250 M HClO? For the reactions of dissociation of base: Next dissociation steps are trated the same way. Calculate the pH of 0.5 M Na3PO4 in aqueous solution m is the molal concentration of the solute in the solution. {{ nextFTS.remaining.days }} State whether the following aqueous solutions are expected to be acidic, basic or neutral It usually results in a bowel movement after 30 minutes to 6 hours. How many grams of Na3PO4 will be needed to produce 575mL of a solution that has a concentration of Na^+ ions of 1.40 M? [12] The United States Food and Drug Administration lists sodium phosphates as generally recognized as safe.[13][14]. Weak acid: one that dissociates incompletely, donating only some of its hydrogen ions into solution, Weak base: a proton acceptor that does not ionize fully in an aqueous solution. Therefore, the numerical value of. Each unit of Na3PO4 that dissociates produces three Na+ ions, which means that there are one-third as many units of Na3PO4 as there are of Na+. {{ nextFTS.remaining.days > 1 ? Operating systems: XP, Vista, 7, 8, 10, 11. From the molecular equation find the overall ionic and net ionic: Molecular: H3PO4 (aq) + 3NaOH (aq) --> Na3PO4 (aq) + 3H2O (l) Write the balanced molecular, complete ionic, and net ionic equations for the reactions that occur when the following are mixed. The anion is phosphate, PO4^-3 and (it has a charge of -3). 1 x 10-14 = K a*Kb Ka = 1x10-14/1.8x10-5 = 5.6 x 10-10 (or look up in table) So, [10], With the formula The item of commerce is often partially hydrated and may range from anhydrous Na3PO4 to the dodecahydrate Na3PO412H2O. D) 4. The figures below illustrate how the vapor pressure of water is affected by the addition of the non-volatile solute, NaCl. Kb and pKb Done on a Dell Dimension laptop computer with a Wacom digital tablet (Bamboo). A) 9. Try It Now, You can create your own Flashcards and upload decks Weak Base Calculations Sodium Phosphate Conjugate Calculate the pH of 0.10 M Na3PO4 solution. Use table search to locate desired compound in database. Note that the molal boiling point elevation constant, K b, has a specific value depending on the identity of the solvent. Which of the following aqueous solutions has the highest boiling point? Na3PO4 is the reaction product of the complete neutralisation of H3PO4 ( a weak acid) with NaOH(a strong base) The salt Na3PO4 will be basic salt. For reference or additional information, please contact websupport@aatbio.com {{ nextFTS.remaining.days === 0 ? Now, the difference between the freezing point of the . I dont know why I was thinking it was going to loose that other hydrogen to become PO43- Got it now! Homework 2 with Answer - Broward College, South Campus Homework 2 CHM As someone who has to write intricate Excel worksheets for preparing buffers at our company, this program [Buffer Maker] seems amazing. PDF TABLE OF CONJUGATE ACID-BASE PAIRS Acid Base Ka (25 C) - umb.edu For the reactions of dissociation of acid: stepwise dissociation constants are defined as. A strong acid is an acid which is completely . TABLE OF CONJUGATE ACID-BASE PAIRS Acid Base K a (25 oC) HClO 4 ClO 4 - H 2 SO 4 HSO 4 - HCl Cl- HNO 3 NO 3 - H 3 O + H 2 O H 2 CrO 4 HCrO 4 - 1.8 x 10-1 H 2 C 2 O 4 (oxalic acid) HC 2 O 4 - 5.90 x 10-2 [H 2 SO 3] = SO 2 (aq) + H2 O HSO Not sure about the ice thing, but SQ means square root. This will give you the Kb. One example is arsenic acid, H 3AsO 4, a triprotic acid.It has three equilibrium expressions associated with its reaction with water: H 3AsO 4 + H 2O ' H 2AsO 4-+ H3O + K a1 = 5.0 x 10-3 H 2AsO 4 Describe two different ways to prepare 500.0 mL of a pH 7.40 buffer where the base concentration if 0.100 M. Boiling Point Elevation - Purdue University 163.94 g/mol. In the Western world, phosphate usage has declined owing to ecological problems with the damage to lakes and rivers through eutrophication. Toggle mobile menu. Acids are classified as either strong or weak, based on their ionization in water. Rated by 1 million+ students Get app now Login. Ka2 = 6.34 x 10 ^ -8. us from charging the card. The larger the value of pKa, the smaller the extent of dissociation. What is the pH of 1.0 M Na3PO4 in aqueous solution - Sarthaks Acids with a pKa value of less than about -2 are said to be strong acids. Therefore the percentage composition of each element is: 69 164 100 = 42.1%N a. Convert grams Na3PO4 to moles or moles Na3PO4 to grams. What is the pH of a 0.01 M Na3PO4 solution? So you can only have three significant figures for any given phosphate species. What is the pH of 1.0 M Na3PO4 in aqueous solution ? So elevation in boiling point will be above a boiling point of water for all solutions. Spark, {{ nextFTS.remaining.months }} Study with Quizlet and memorize flashcards containing terms like What is the pH of a 6.00 M H3PO4 solution? 'months' : 'month' }} The pH of a solution is a measure of the molar concentration of hydrogen `(H^+)` , or hydronium `(H_3O^+)` ions of the solution. . As we can see in the second step, HPO is the conjugate base of HPO. The Kb for NH3 is 1 10-5. CHEBI:37583. pKa and pKb values have been taken from various books and internet sources. Assuming equal concentrations, rank these aqueous solutions by their freezing point: LiSO4, Li3PO4, SnCl4, NH4Br. Non-Zwitterionic Buffer Compound Formula MW Solubility pKa at 20 C g/100 mL of H2O at 20 C 1 2 3 Boric Acid H3BO3 61.8 6.4 Please remember that only some of them are included in the trial version database, but you can always enter them manually for calculations. The disodium hydrogen phosphate is reacted with sodium hydroxide to form trisodium phosphate and water. Acid pH = Base Hydrolysis Reaction Ka Kb 2.4E-02 pka E pKb Calculations: Note that ammonia and most organic bases release OH- ions due to hydrolysis, not dissociation. Potassium Nitrite Calculate the pH of 0.10 M KNO2 solution. The three equilibria values for H 3 PO 4, H 2 PO 4-, and HPO 42- are: Ka1 = 7.11 x 10 ^ -3. PO Error: equation KI+Na3PO4=KNa+IPO4 is an impossible reaction Please correct your reaction or click on one of the suggestions below: KI + Na3PO4 = K3PO4 + NaI KI + Na3PO4 = KPO4 + Na3I Instructions and examples below may help to solve this problem You can always ask for help in the forum Why aluminium nitride AlN has higher melting point than Lithium oxide? How many moles of sodium ions are present in 2.50 L of 0.300 M Na3PO4? kcabwalc sdliug . The figure below shows a microscopic view of the surface of pure water. C) Weak acid vs. strong base. Acid-Base Pairs, Strength of Acids and Bases, and pH - Purdue University Contact. The logarithmic constant (pKa) is equal to -log10(Ka). Now let's try some numbers. Acid with values less than one are considered weak. So we start with 0.090 mol of both NH4 + and NH 3.After complete reaction with 0.0010 mol NaOH the resulting amounts of each are: 0.090 - 0.0010 = 0.089 mol NH4 0.090 + 0.0010 = 0.091 mol NH3 To use Henderson-Hasselbalch equation we need to know the pKa value. Table of Acid and Base Strength - University of Washington Calculating pH of a Na2HPO4 solution - Student Doctor Network Why is a sodium phosphate buffer used for the pH 6.24 buffer? You are using an out of date browser. I dont know why I can't the right answer but any help would be great! 'months' : 'month' }}, {{ nextFTS.remaining.days }} {{ nextFTS.remaining.days }} By the end of the 20th century, many products that formerly contained TSP were manufactured with TSP substitutes, which consist mainly of sodium carbonate along with various admixtures of nonionic surfactants and a limited percentage of sodium phosphates. Here are some of the values of weak and strong acids and bases dissociation constants used by BATE when calculating pH of the solution and concetrations of all ions present. CCRIS 7086. Note that the molal boiling point elevation constant, Kb, has a specific value depending on the identity of the solvent. Osmosis is the flow of a solvent into a solution through a semipermeable membrane. 4 What is the pOH of a .22 M NaOH solution? Conjugate Acid-Base Pairs. The ionization for a general weak acid, HA, can be written as follows: Because the acid is weak, an equilibrium expression can be written. What is the molar concentration of sodium ions in a 0.450 M Na3PO4 NaCl is added slowly to a solution that is 0.010 M each in Cu+, Ag+, and Au+. How do you arrange these aqueous solutions in order of decreasing freezing point: 0.10 m Na3PO4, 0.35 m NaCl, 0.20 m MgCl2, 0.15 m C6H12O6, and CH3OOH? The 3 Month (100 Day) MCAT Study Schedule Guide: 2022 Edition, All resources are student and donor supported. We are not permitting internet traffic to Byjus website from countries within European Union at this time. there are fewer water molecules in the vapor (i.e., lower vapor pressure) above the NaCl solution than in the vapor above pure water, and. m is the molal concentration of the solute in the solution. What is the osmotic pressure of a solution prepared by adding 13.65 g of sucrose (C 12 H 22 O 11) to enough water to make 250 mL of solution at 25 C? 3.5 b. This shows sodium phosphate to be about 42.07% sodium by mass. So, to three significant figures, for any sort of mixture of N a X 2 H P O X 4 and N a X 3 P O X 4 salts you'll need to consider both p K a 2 and p K a 3 and you'll end up with a quadratic equation to solve. Calculate the pH of the salt solution of Ca (OOCCH_3)_2, 0.1 M. Calculate the pH of the salt solution of AlCl, 0.1 M, K=10^+. Phosphate ions are used as a buffer because there are three protonated forms (H3PO4, H2PO4-, and HPO42-) that have pKa in the correct .