Couple of problems left over from Chem homework I didn't get.

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SUMMARY

The discussion focuses on solving two titration problems from an AP Chemistry assignment. The first problem involves determining the molecular weight of an acid using a .1302M NaOH solution, where 1.863 grams of the acid requires 70.11mL of NaOH. The second problem calculates the concentration of Fe(II) using a .3136M Ce(IV) solution to titrate a 10.00mL aliquot. The correct approach for both problems involves using the moles of titrant and the stoichiometry of the reactions, specifically applying the formula (moles per liter of titrant) * (liters of titrant) = moles of titrant.

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  • Understanding of titration concepts and stoichiometry
  • Familiarity with molarity calculations
  • Knowledge of acid-base reactions and molecular weight determination
  • Ability to perform unit conversions and dimensional analysis
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  • Review the concept of molarity and its application in titration problems
  • Study stoichiometric calculations in acid-base reactions
  • Practice determining molecular weights from titration data
  • Explore the use of limiting reagents in chemical reactions
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High school chemistry students, AP Chemistry learners, and educators looking to enhance their understanding of titration techniques and stoichiometric calculations.

Radja24
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Hi, I'm taking AP Chem this year, and we just had this big assignment. I got through most of it, but here's some I need a walkthrough with.

Homework Statement


A titration is done using .1302M NaOH to determine the molecular weight of an acid. The acid contains one acidic hydrogen per molecule. If 1.863 grams of the acid requires 70.11mL of the NaOH solution, what is the molecular weight of the acid?

Here's the second one:

Fe (II) + Ce (IV) -----> Fe (III) + Ce (III)

What is the concentration of Fe(II) if it requires 21.35mL of .3136 M Ce (IV) to titrate a 10.00mL aliquot to the endpoint?

Attempt:

1st one, I tried to get moles of NaOH and then multiply it by 110 to get 1 mole, then multiply 1.863 by 110...but that makes no sense.
For the second, I tried using MfVf formula for titration, and before that I tried to get the moles of Ce (Iv) once again, and then find the limiting agent and plug and go from there, but I sincerely am stuck.
These were two ones I couldn't get really get after some nonsense work. Please help...
 
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The basic plan for both is answer the question of how many MOLES were titrated?
Each of those analyses use 1:1 mole ratios of titrant to analyte being sought.

(moles per liter of titrant)*(liters of titrant) = moles of titrant
 
For the second one I did .3136 * .02135 to get .0067 moles Ce (IV)m then multiplied .0067 * .01 Liters to get .000067 moles of titrant, and then I divided that number by .01 L to get .0067 M as my answer
 

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