Title: E3 Quiz
Course: Lab Instruments I > Section: E3: Meetings 4,5,6,7

This quiz covers objectives for Experiment Set 3: Titrations.

Have a periodic table or list of formula (molar) masses available before beginning.

Q: A buret dispenses a solution termed the ____.
- titrant
- analyte
- standard solution
- titrated substance
A: titrant

Q: In a standardization procedure, the solution to be standardized is the ____.
- solution in the buret
- solution of known concentration
- solution of unknown concentration
- solution in the flask below the buret
A: solution of unknown concentration

Q: What is the endpoint of a titration?
- The point in a titration in which the auto-titrator is programed to stop adding titrant to the titrated substance.
- The point in a titration that closely approximates when the auto-titrator stopped adding titrant to the titrated substance.
- The point in a titration in which stoichiometrically equivalent quantities of the standard substance and analyte have reacted.
- The point in a titration that closely approximates when stoichiometrically equivalent quantities of the standard substance and analyte have reacted.
A: The point in a titration that closely approximates when stoichiometrically equivalent quantities of the standard substance and analyte have reacted.

Q: A substance that is hygroscopic (absorbs water from the air) is an ideal primary standard.
- True
- False
A: False

Q: A pipet stamped TD without frosted rings is designed to deliver the indicated volume while retaining a small amount of liquid in the tip.
- True
- False
A: True

Q: Class A volumetric flasks are more stringently calibrated than Class B volumetric flasks.
- True
- False
A: True

Q: A dibasic substance can accept two hydrogen ions.
- True
- False
A: True

Q: A solution having a pH greater than 7 is acidic.
- True
- False
A: False

Q: Which of the following is accurate for selecting an acid-base indicator?
- It must undergo a color change within the pH range before the vertical or near vertical portion of a titration curve.
- It must undergo a color change within the pH range after the vertical or near vertical portion of a titration curve.
- It must undergo a color change within the pH range that encompasses the vertical or near vertical portion of a titration curve.
- It must undergo a color change in the middle of the pH range that encompasses the vertical or near vertical portion of a titration curve.
A: It must undergo a color change within the pH range that encompasses the vertical or near vertical portion of a titration curve.

Q: Ethylenediamine is a bidentate ligand. What does that mean?
- The ethylenediamine molecule forms two complex ions.
- Two ethylenediamine molecules form a complex ion with one metal cation.
- One ethylenediamine molecule forms a complex ion with two metal cations.
- The ethylenediamine complex ion consists of two ethylenediamine molecules.
A: The ethylenediamine complex ion consists of two ethylenediamine molecules.

Q: A primary purpose of an EDTA titration in an analytical laboratory is to _____.
- determine water pH
- purify water solutions
- standardize water solutions
- determine water hardness
A: determine water hardness

Q: The primary standard “TRIS” (molar mass = 121.14 g/mol) is used to standardize a solution of sulfuric acid, H_2SO_4. In the reaction, 2 moles of TRIS react with every 1 mol of H_2SO_4. If 1.2031 g TRIS are used and 23.45 mL of sulfuric acid are needed, what is the molarity of the H_2SO_4?
- 0.1026 M
- 0.2118 M
- 0.4235 M
- 0.8470 M
A: 0.2118 M

Q: What is the molarity of a solution of sulfuric acid, H_2SO_4, that was used to titrate 0.1053 M KOH, potassium hydroxide, if 20.00 mL of the base was neutralized by 39.04 mL of the acid in the reaction shown below?

2 KOH + 1 H_2SO_4 à K_2SO_4 + 2 H_2O
- 0.02697 M
- 0.05394 M
- 0.1028 M
- 0.1079 M
A: 0.02697 M