What is the Percent Oxalic Acid Dihydrate in an Unknown Sample?

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In summary, the conversation discusses determining the percentage of oxalic acid dihydrate in an impure sample. In the first part, 0.110 grams of the sample is dissolved in water and titrated with 0.140 M NaOH, requiring 10.10 mLs to reach the endpoint. The percentage of oxalic acid dihydrate is calculated to be 61.8%. In the second part, 0.121 grams of pure oxalic acid dihydrate is dissolved in water and titrated with the same NaOH solution, requiring 14.22 mLs to reach the endpoint. The molarity of the NaOH solution is calculated to be 1.919*10^-3 moles. The conversation also touches
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Homework Statement


You are given an impure sample of oxalic acid dihydrate (MW=126.068 g/mole) and asked to determine the percent of oxalic acid dihydrate present in the sample. You place 0.110 grams of the unknown sample in an Erlenmeyer flask and dissolve it in distilled water. Titration with 0.140 M standardized NaOH solution requires 10.10 mLs to reach the titration endpoint. What is the percent of oxalic acid dihydrate in the sample?2. 0.121 grams of oxalic acid dihydrate (MW=126.068 g/mole) is dissolved in water in an Erlenmeyer flask. Remember that each mole of oxalic acid dissolved in water results in 2 moles of hydronium ion so it takes 2 moles of NaOH to neutralize one mole of oxalic acid. It requires 14.22 mLs of your prepared sodium hydroxide solution to reach the endpoint of the titration. What is the molarity of your NaOH solution?

I need to know if this is right at my attemps.

Homework Equations



stochiometry

The Attempt at a Solution



attempt for number 1: (10.10ml)*(1l/1000ml)*(0.140 moles of NaOH/1L)= 1.41*10^-3 moles of Naoh
(0.110 g of oxidic acid)*(1 mole oxidic acid/126.068 g)=8.72*10^-4 MOLE OF OXIDIC ACID
the percetage of oxidic acid, which is what we are looking for i think is 8.72*10^-4moles of oxicid/1.40*10^-3 moles of naOH times 100=61.8 % of oxidic acid

Attempt for number 2: 0.121 g of H2C2O4 *1 mole H2C2O4/126.063 g of H2C2O4=9.59*10^-4 then, 9.59*10^-4 moles of H2C2O4*2moles of NaOH/1 mole of H2C2O4= 1.919*10^-3 moles of NaOH
 
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  • #2
You should be more careful with your 'stochiometry' (stoichiometry). Is oxalic acid monoprotic?
 
  • #3
What do you mean by monoprotic?? never heard of this before. hahaha! All i know is that oxalic acid reacts with 2 moles of NaOH to neutralize the concentration.
 
  • #4
Yeah, but if it takes two moles of NaOH to neutralize only one mole of oxalic acid...
 
  • #5
then what does that mean, that is monoprotic??
 
  • #6
HA <-> H+ + A- - monoprotic (like HCl, or HNO3).

H2A <-> 2H+ + A2- - diprotic (like oxalic, or H2SO4); note that dissociation is in reality stepwise.

Triprotic (tetra...) left as an exercise for the reader.
 

FAQ: What is the Percent Oxalic Acid Dihydrate in an Unknown Sample?

1. What is the difference between an element and a compound?

An element is a pure substance that is made up of only one type of atom. Elements cannot be broken down into simpler substances through chemical reactions. On the other hand, a compound is a substance made up of two or more elements chemically bonded together. Compounds can be broken down into their constituent elements through chemical reactions.

2. How do you determine the number of protons, neutrons, and electrons in an atom?

The atomic number of an element tells you the number of protons in an atom of that element. The atomic mass tells you the total number of protons and neutrons in the atom. To determine the number of electrons, you can use the atomic number as well since atoms are electrically neutral and have the same number of protons and electrons.

3. What are the three states of matter and how do they differ?

The three states of matter are solid, liquid, and gas. In a solid, the atoms or molecules are tightly packed and have a fixed shape and volume. In a liquid, the atoms or molecules are more spread out and can move around, giving it a definite volume but not a definite shape. In a gas, the atoms or molecules are far apart and constantly moving, giving it neither a definite shape nor volume.

4. How do you balance a chemical equation?

To balance a chemical equation, you need to ensure that the number of atoms of each element is the same on both sides of the equation. This is done by adding coefficients in front of each molecule to indicate the number of each molecule needed to balance the equation. It is important to note that you cannot change subscripts as this would change the identity of the molecule.

5. What is the difference between an exothermic and endothermic reaction?

An exothermic reaction releases energy in the form of heat, light, or sound, and the products have less energy than the reactants. On the other hand, an endothermic reaction absorbs energy, usually in the form of heat, and the products have more energy than the reactants. Exothermic reactions are characterized by a rise in temperature, while endothermic reactions are characterized by a decrease in temperature.

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