It requires 23.91 mL of of 0.01500 M HCl to neutralize 20.00 mL of an unknown Ca(OH)2.  Calculate the initial Ca(OH)2 concentration. 2HCl   +   Ca(OH)2   ⇋   CaCl2   +   2H2O

For humans to maintain the pH of their blood close to 7.4, the body uses three buffer systems: carbonate, phosphate and proteins. If the pH of the blood goes below 6.8 or above 7.8, death may result. Imagine you want to make a phosphate buffer in the lab that resembles the bloods phosphate buffer. You start by mixing 0.95 M NaH2PO4 and 0.68 M Na2HPO4. H2PO4-  + H2O ⇌  HPO42-  + H+  pKa= 7.21  (5 marks total) a. From the reaction above indicate the weak acid and the conjugate base involved in making this buffer. (2 marks) b. Calculate the pH of the phosphate buffer solution. Provide your answer with 2 decimal places (2 marks) c. If the pH calculated in b. was the blood pH of an actual patient, would you say this patient’s blood pH is in the normal range or are they suffering from alkalosis or acidosis? (1 mark)

A pipette is used to add 41 mL of 0.2 M Pb(NO3)2 to a 268.0 mL solution of 0.2 M NaF. Determine the equilibrium concentration of Pb2+(aq) in the final solution. Ksp(PbF2)=3.6E-8Include at least 3 significant figures in your answer.

Two 25.0-mL. samples of unknown monoprotic weak acids, A and B, are titrated with 0.100 M NAOH solutions. The titration curve for each acid is shown below ACID A ACID B 14 14 12 12 10 10 10 15 20 25 30 35 40 45 30 5 10 15 20 25 30 33 40 45 30 Vohume of NaOH added (ml) Volume of NaOH added (ml ) Part A Which of the two weak acid solutions is less concentrated? B A. Submit Bequest Answer

Answer Questions #27 through #31 about the titration curves below (labeled a and b) for two different bases. The titrant acid used in both cases was 0.100 M HCl and the volume of the base solutions in both cases was 75.0 mL mL. 14 14 12 12 - 10- 10 8- 6. 4. 2- 2- 20 40 60 80 100 20 40 60 80 100 Volume of acid added (mL) (a) (b) Volume of acid added (mL) 2014 Pearson Education Inc P Type here to search 11:17 AM (? 3/18/2021 -> ort sc 80 6. ece num ER/TY || на 0 04 2C Hd

3a) A student determines the concentration of a sodium hydroxide solution by titration with standardized KHP. S/he obtains the values: 0.190 M, 0.202 M, and 0.205 M. Should the value 0.190 M be rejected? Apply the Q Test. For three values Q must be greater than 0.94 to reject the number. Q = suspect nearest | largest - - smallest b) The student de to repeat the experiment two more The five values now include: 0.190 M, 0.202 M, 0.205 M, 0.201M and 0.203M. Use the Q Test to see if the first value may be rejected. For five values Q must be greater than 0.64 to reject the number. c) Solve for the average Molarity of the measurements from part b with and without the rejected number. Is there value in repeating an experiment several times?

1. How do you prepare a 100mL of 0.1 M phosphate buffer?To make 100 mL of 0.1 M phosphate buffer: Calculate the amount of sodium phosphate needed. moles of sodium phosphate = (0.1 mol/L) x (0.1 L) = 0.01 moles mass of sodium phosphate = moles x molar mass = 0.01 moles x 142 g/mol = 1.42 g Dissolve 1.42 g of sodium phosphate in distilled water in a 100 mL volumetric flask. Adjust the pH of the solution to the desired value (usually around 7.4) using a strong acid or strong base. Bring the solution to the final volume (100 mL) with distilled water.   2. From the anterior buffer, how do you make 100mL of 0.05 M? To make 100 mL of 0.05 M phosphate buffer from the 0.1 M stock solution: Calculate the amount of the 0.1 M phosphate buffer needed. moles of phosphate buffer = (0.05 mol/L) x (0.1 L) = 0.005 moles Calculate the volume of the 0.1 M phosphate buffer needed. moles = concentration x volume (in liters) volume = moles / concentration = 0.005 moles / 0.1 mol/L = 0.05 L or 50 mL Measure…

Calculate the final [Ag1+] concentration in solution when 0.035 moles of AgNO3 are added to 500. mL of 0.21 M NaCN. Assume the volume remains constant. Ksp = 1.2 ✕ 10-16 for AgCN. (in M)

Determine the pH of a buffer solution by constructing an ICE table, writing the equilibrium constant expression, and using this information to determine the pH. The Ka for CH COOH is 1.8 x 10%. Complete Parts 1-3 before submitting your answer. 2 3 NEXT > The buffer was prepared by dissolving 20.0 g NaCH,COO into a 500.0 mL solution of 0.150 M of CH COOH. Assume the volume of the solution does not change. Fill in the ICE table with the appropriate value for each involved species to determine concentrations of all reactants and products. Initial (M) Change (M) Equilibrium (M) CH COOH(aq) H₁₂O(I) HO*(aq) CH COO(aq)

The silver-ion concentration in a saturated solution of silver(1) sulfate is 2.9 x 10-2 M. What is Ksp for silver(1) sulfate? 2.1 x 104 8.3 x 10-4 1.2 x 10-5 9.8 x 10-5 6.9 x 10-7