A buffer with pH = 8.96 must be created. 8.90 g of the acid component of the best buffer system will be used, and the volume of the solution will be 1 L. Choose which is the best buffer system, then compute the mass of the salt or base component of the chosen system.   Choices:  HClO (Ka = 2.9 x 10-8 , 52.46 g/mol)& KClO (90.55 g/mol)  NH3 (Ka = 5.65 x 10-10 , 17.031g/mol) &NH4Cl (53.491 gmol) CH3COOH (Ka = 1.77 x 10-5 , 60.052 g/mol) & CH3COOK (98.15 g/mol) HClO2 (Ka = 1.1 x 10-2 , 68.46 g/mol)) & KClO2 (106.55 g/mol)

Calculate the concentration (molarity) of Pb2+ ions in a solution made by adding 0.010 moles of Pb(NO3)2 to 1.0 L of a  2.0 M NaI solution.  (Kf = 3.0 x 104 for PbI42−) - 4.9 x 10−2 -3.3 x 10−5 - 2.1 x 10−7 -1.7 x 10−7 -2.3 x 10−8

A student performed titration to determine the concentration of citric acid with potassium permanganate solution. The net ionic equation is as follows: 5C6H8O7  + 18MnO4-   + 54H+  → 30CO2  + 47H2O  + 18Mn2+ The concentration of potassium permanganate soluiton is 0.266 M. The volume of lemon juice is 25.00 mL. The titration consumed 17.6  mL of potassium permanganate solution to reach the endpoint. Determine the moles of citric acid in the lemon juice sample.

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…

40 mL of LiOH are titrated to the equivalence point with 65 mL of 1.2 x 10-2 M HNO3. Find the concentration (molarity) of the LiOH solution.

A buffer solution is made that is 0.492 M in H2S and 0.492 M in KHS. If Ka1 for H2S is 1.00x10^-7, what is the pH of the buffer solution? pH =  Write the net ionic equation for the reaction that occurs when 0.135 mol NaOH is added to 1.00 L of the buffer solution. (Use the lowest possible coefficients. Omit states of matter.)   +       +

A student prepared 100.0 mL of a buffer in the lab that contains 0.300 M of a weak acid, HA, and 0.200 M of its conjugate base, NaA. The student then added 1.0x10 moles of NaOH to the buffer. a) Write down your student name and number b) Write down how the student calculated the final moles of A and HA after adding the NaOH: moles A finl =2.0x102 mole - 1.0x10-3mole moles HA na = 3.0x102mole +1.0x10-3mole c) There is an error in their formula. Identify the error d) Calculate the correct final moles of A and HA

A 25.0 mL volume of HCl solution of unknown concentration is titrated with a 0.124 M NaOH solution. Neutralization of the HCl solution requires 42.1 mL of the NaOH solution. Calculate the concentration of the HCl solution. [HC1] = M %3D

You need to create a buffer at a pH of 4.6, and have a 20 mL solution of 0.22 M CH3COOH. What volume of 0.22 M CH3COONa solution would you need to add to the acetic acid? Ka=1.82×10^-5?