A chemistry student needs to standardize a fresh solution of sodium hydroxide. She carefully weighs out 434. mg of oxalic acid (H₂C₂O4), a diprotic acid that can be purchased inexpensively in high purity, and dissolves it in 250. mL of distilled water. The student then titrates the oxalic acid solution with her sodium hydroxide solution. When the titration reaches the equivalence point, the student finds she has used 144.7 mL of sodium hydroxide solution. Calculate the molarity of the student's sodium hydroxide solution. Round your answer to 3 significant digits. 0x10

A chemistry student needs to standardize a fresh solution of sodium hydroxide. She carefully weighs out 434. mg of oxalic acid (H₂C₂O4), a diprotic acid that can be purchased inexpensively in high purity, and dissolves it in 250. mL of distilled water. The student then titrates the oxalic acid solution with her sodium hydroxide solution. When the titration reaches the equivalence point, the student finds she has used 144.7 mL of sodium hydroxide solution. Calculate the molarity of the student's sodium hydroxide solution. Round your answer to 3 significant digits. 0x10

Chemistry: Matter and Change

1st Edition

ISBN:9780078746376

Author:Dinah Zike, Laurel Dingrando, Nicholas Hainen, Cheryl Wistrom

Publisher:Dinah Zike, Laurel Dingrando, Nicholas Hainen, Cheryl Wistrom

Chapter18: Acids And Bases

Section: Chapter Questions

Problem 92A

See similar textbooks

Similar questions

Describe how the amount of sodium hydroxide in a mixture can be determined by titration with hydrochloric acid of known molarity.
A student is given 0.930 g of an unknown acid, which can be either oxalic acid, H2C2O4, or citric acid, H3C6H5O7. To determine which acid she has, she titrates the unknown acid with 0.615 M NaOH. The equivalence point is reached when 33.6 mL are added. What is the unknown acid?
One half liter (500. mL) of 2.50 M HCl is mixed with 250. mL of 3.75 M HCl. Assuming the total solution volume after mixing is 750. mL, what is the concentration of hydrochloric acid in the resulting solution? What is its pH?
A solution of sodium cyanide, NaCN, has a pH of 12.10. How many grams of NaCN are in 425 mL of a solution with the same pH?
Calcium carbonate, CaCO3, can be obtained in a very pure state. Standard solutions of calcium ion are usually prepared by dissolving calcium carbonate in acid. What mass of CaCO3 should be taken to prepare 500. mL of 0.0200 M calcium ion solution?
What mass of solid aluminum hydroxide can be produced when 50.0 mL of 0.200 M Al(NO3)3 is added to 200.0 mL of 0.100 M KOH?
An acid is titrated with NaOH. The following beakers are illustrations of the contents of the beaker at various times during the titration. These are presented out of order. Note: Counter-ions and water molecules have been omitted from the illustrations for clarity. (a) (b) (c) (d) (e) a. Is the acid a weak or strong acid? How can you tell? b. Arrange the beakers in order of what the contents would look like as the titration progresses. c. For which beaker would pH = pKa? Explain your answer. d. Which beaker represents the equivalence point of the titration? Explain your answer. e. For which beaker would the Ka value for the acid not be necessary to determine the pH? Explain your answer.
You are given four different aqueous solutions and told that they each contain NaOH, Na2CO3, NaHCO3, or a mixture of these solutes. You do some experiments and gather these data about the samples. Sample A: Phenolphthalein is colorless in the solution. Sample B: The sample was titrated with HCl until the pink color of phenolphthalein disappeared, then methyl orange was added. The solution became pink. Methyl orange changes color from pH 3.01 (red) to pH 4.4 (orange). Sample C: Equal volumes of the sample were titrated with standardized acid. Using phenolphthalein as an indicator required 15.26 mL of standardized acid to change the phenolphthalein color. The other sample required 17.90 mL for a color change using methyl orange as the indicator. Sample D: Two equal volumes of the sample were titrated with standardized HCl. Using phenolphthalein as the indicator, it took 15.00 mL of acid to reach the equivalence point; using methyl orange as the indicator required 30.00 mL HCl to achieve neutralization. Identify the solute in each of the solutions.
95. Many metal ions form insoluble sulfide compounds when a solution of the metal ion is treated with hydrogen sulfide gas. For example, nickel(II) precipitates nearly quantitatively as NiS when H2S gas is bubbled through a nickel ion solution. How many milliliters of gaseous H2S at STP are needed to precipitate all (he nickel ion present in 10. mL of 0.050 M NiCl2 solution?
Acrylic acid is used in the polymer industry in the production of acrylates. Its K, is 5.6 X 10“’. What is the pH of a 0.11 M solution of acrylic acid, CH2CHCOOH?
A mountain lake that is 4.0 km × 6.0 km with an average depth of 75 m has an H+(aq) concentration of 1.3 × 10−6 M. Calculate the mass of calcium carbonate that would have to be added to the lake to change the H+(aq) concentration to 6.3 × 10−8 M. Assume that all the carbonate is converted to carbon dioxide, which bubbles out of the solution.
A bottle of concentrated hydroiodic acid is 57% HI by weight and has a density of 1.70 g/mL. A solution of this strong and corrosive acid is made by adding exactly 10.0 mL to some water and diluting to 250.0 mL. If the information on the label is correct, what volume of 0.988 M NaOH is needed to neutralize the HI solution? Suggest an indicator for the titration.