Titration, Part 2

Experiment 10 – Titration, Part 2

CHM 1045L – Fall 2020 – PBSC

Name: Click or tap here to enter text. Date of Experiment: Click or tap to enter a date.

Pre-lab Setup

Type out the chemicals used in this experiment, their hazards if applicable, and any other safety concerns associated with this experiment.

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Type the procedure for this experiment in your own words, as though you were completing this experiment in the lab yourself. Feel free to use a bullet list (avoid huge paragraphs).

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Pre-lab Questions

1. Briefly explain why we do not need an indicator for this titration.

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2. In this reaction, we dissolve ten iron tablets to make a stock solution with a volume of 250 mL. How many iron tablets does the 25 mL sample used for the titration contain?

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3. What is the balanced equation for the redox reaction used in this titration? Use this website if you get stuck. Be sure to use subscripts and superscripts when appropriate, but you may omit states of matter (such as (aq)).

 

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Data

Table 1. Titration of Iron with Permanganate. Fill out the table with your data. Keep an eye on sigfigs!

 

 

Rough Trial

 

1st Accurate Trial

 

2nd Accurate Trial

 

3rd Accurate Trial

 

Iron solution volume for titration (mL)

 

25.00 mL

 

25.00 mL

 

25.00 mL

 

25.00 mL

 

Final burette reading (mL)

 

 

 

 

 

 

 

 

 

Initial burette reading (mL)

 

 

 

 

 

 

 

 

 

Volume added (mL)

 

 

 

 

 

 

 

 

 

Average volume added (mL)

 

 

 

 

 

Post-lab Questions

1. What was the concentration of your iron solution? What was your calculated mass of iron in one tablet, in milligrams? Show all work at the end of the worksheet, with units included and steps labeled.

Concentration of iron tablet solution: Click or tap here to enter text.

 

Mass iron in one tablet: Click or tap here to enter text.

2. Based on your results, is the amount of iron listed on the supplement label correct? If not, what is the percent error? Percent error = (experimental value – “true” value) / (“true” value). Multiply the value by 100 to turn it into a percent.

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Calculations/Work

1. Add a picture of your work for post-lab question #1 below. Include all steps (from determining concentration and moles of MnO4 all the way to determining grams of iron per tablet). Don’t forget units!