7. A laboratory needs to find out the concentration of a solution of nitrous acid (HNO2,...
A chemist had a bottle of HCl (aq) of unknown concentration. She performed a titration experiment in order to determine its concentration. She pipeted 25.00 mL of the HCl solution into an Erlenmeyer flask. She then added about 21 mL of deionized water and 3 drops of phenolphthalein indicator dye to the flask. She titrated this mixture with 0.09063 M NaOH (aq), and obtained a permanent, pale pink endpoint after the addition of 36.68 mL of NaOH (aq). Given that...
3. A student pipetted 25.00 mL of a 0.2531 M solution of HCl into an Erlenmeyer flask. After adding 3 drops of phenolphthalein indicator to the flask, the student started adding NaOH from the burette, until the color in the Erlenmeyer flask turned light pink, The student calculated that 21.40 mL NaOH was transferred in the flask to neutralize the acid. a) Calculate the number of moles of HCl initially present (Reaction: NaOH(aq) + HCl(aq) -NaCl(aq) + H2O() b) Calculate...
A chemist needs to determine the concentration of a sulfuric acid solution by titration with a standard sodium hydroxide solution. He has a 0.1435 M standard sodium hydroxide solution. He takes a 25.00 mL sample of the original acid solution and dilutes it to 250.0 mL. Then, he takes a 10.00 mL sample of the dilute acid solution and titrates it with the standard solution. The endpoint was reached after the addition of 13.55 mL of the standard solution. What...
A chemist needs to determine the concentration of a sulfuric acid solution by titration with a standard sodium hydroxide solution. He has a 0.1494 M standard sodium hydroxide solution. He takes a 25.00 mL sample of the original acid solution and dilutes it to 250.0 mL. Then, he takes a 10.00 mL sample of the dilute acid solution and titrates it with the standard solution. The endpoint was reached after the addition of 18.48 mL of the standard solution. What...
A chemist needs to determine the concentration of a sulfuric acid solution by titration with a standard sodium hydroxide solution. He has a 0.1354 M standard sodium hydroxide solution. He takes a 25.00 mL sample of the original acid solution and dilutes it to 250.0 mL. Then, he takes a 10.00 mL sample of the dilute acid solution and titrates it with the standard solution. The endpoint was reached after the addition of 16.78 mL of the standard solution. What...
Potassium hydrogen phthalate is a solid, monoprotic acid frequently used in the laboratory as a primary standard. It has the unwieldy formula of KHC8H4O4. This is often written in shorthand notation as KHP. If 37.5 mL of a sodium hydroxide solution are needed to neutralize 2.14 grams of KHP, what is the molarity of the sodium hydroxide solution? __________M Oxalic acid dihydrate is a solid, diprotic acid that can be used in the laboratory as a primary standard. Its formula...
A 25.00 mL volume of an HA acid solution of unknown concentration with 2 drops of phenolphthalein requires 0.1320 M NaOH was put in buret to reach the endpoint in the titration. The initial reading & fina reading of NaOH is shown in the picture Initial 9.63 mL 24.16 ml Volume of HA acid (mL) Volume of NaOH (mL) Molar concentration of NaOH (molL) We were unable to transcribe this image
Concentration of NaOH = 1600 x10- Molar Sodium hydroxide Nach Trial 1 Trial 2 Trial Trial 4 2.60/1.20 1.40/1.30 28.20 29.10.26.1026.50 Volume of NaOH added Initial buret reading Final buret reading Moles of NaOH added Moles of HCl reacted Molarity of diluted HCI Molarity of undiluted HCI Average molarity of undiluted HCI Precision PROCEDURE 1. Obtain approximately 40 mL of an unknown acid in an Erlenmeyer flask from your teaching assistant. 2. Clean your 250-ml volumetric flask (contains exactly 250.00...
(4.) The flask shown here contains 0.636 g of acid and a few drops of phenolphthalein indicator dissolved in water. The buret contains 0.240 M NaOH. What volume of base is needed to reach the end point of the titration? Assuming the acid is monoprotic, what is its molar mass? (5.) 20.00 mL of a H2SO4 solution with an unknown concentration was titrated to a phenolphthalein endpoint with 39.09 mL of a 0.1315 M NaOH solution. What is the concentration...
Concentration of NaOH = 1600 x10- Molar Sodium hydroxide Nach Trial 1 Trial 2 Trial Trial 4 2.60/1.20 11.40/1.30 28.20 29.10.26.1026.50 Initial buret reading Final buret reading Volume of NaOH added Moles of NaOH added Moles of HCl reacted Molarity of diluted HCI Molarity of undiluted HCI Average molarity of undiluted HCI Precision PROCEDURE 1. Obtain approximately 40 mL of an unknown acid in an Erlenmeyer flask from your teaching assistant. 2. Clean your 250-ml volumetric flask (contains exactly 250.00...