Pre-Lab Quiz

Investigation 11 PreLab Quiz

Chapter 1. Investigation 11 PreLab Quiz

Pre-Lab Quiz

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You must read each slide, and complete any questions on the slide, in sequence.

1.

What technique is used in this investigation?

Colorimetry

Calorimetry

Gas pressure measurements

Titration

Combustion analysis

Correct.

Incorrect.

2.

What reaction type is involved in this investigation?

Combustion reactions

Acid-base neutralization reactions

Single-displacement reactions

Decomposition reactions

Oxidation-reduction reactions

Correct.

Incorrect.

3.

What standardized base is used in this investigation?

Acetic acid

potassium hydroxide

sodium hydroxide

sodium choride

Correct.

Incorrect.

4.

The figure shows a final burette volume reading during a titration using a 50 mL burette. First determine the value of each increment, and then read the level of the liquid. Which of the following is closest to what you would record for this measurement, to the correct number of significant figures?

39.2 mL

39.23 mL

39.18 mL

40.7 mL

Correct.

Incorrect.

5.

Which of the following is something that would cause error in titration measurements?

Adding water to the titrant solution in the burette

Adding water to the solution in the flask (the analyte) during the titration

Washing the tip of the burette into the analyte solution with water

Rinsing the burette with titrant before filling it with titrant

Removing bubbles from the tip before making the initial burette reading

Correct.

Incorrect.

6.

How do you know when just enough NaOH is added to completely react with the acid?

The volume of NaOH solution added from the burette is equal to the volume of acid used in the titration

Phenolphthalein in the solution turns very dark pink

Phenolphthalein in the solution turns very light pink

Bubbles start to form.

A precipitate forms, giving a cloudy appearance to the solution.

Correct.

Incorrect.

7.

When starting a titration, is it critical that the initial burette volume reading be 0.00 mL?

Yes

Correct.

Incorrect.

8.

Calculate the number of moles of H₂SO₄ required to neutralize 40.00 mL of 0.500 M NaOH. Be sure to consider the coefficients in the balanced equation for the reaction:

H₂SO₄(aq) + 2NaOH(aq) -----> Na₂SO4(aq) + 2H₂O(l)

0.0400 mol

0.250 mol

0.0200 mol

0.0100 mol

0.00500 mol

Correct.

Incorrect.

9.

Calculate the molarity of HC₂H₃O₂ if 25.0 mL of 0.500 M NaOH is required to neutralize 10.00 mL of HC₂H₃O₂ solution. Be sure to consider the coefficients in the balanced equation for the reaction.

1.25 M

0.0125 M

0.625 M

0.200 M

0.800 M

Correct.

Incorrect.