How to fill/write the chemistry procedure?

Question

You were asked at design an experimental procedure to determine the molarity of a NaOH solution using pure solid oxalic acid dihydrate, H2C2O4 · 2H2O. You will use an aqueous solution of NaOH and an aqueous solution of oxalic acid dihydrate, H2C2O4 · 2H2O for your titration.

Q1. What solution will the buret contain? Is the concentration of the solution known or unknown at the start of the titration? Does this solution contain an indicator?

Q2. What solution will the Erlenmeyer flask contain? Is the concentration of the solution known or unknown at the start of the titration ? Does this solution contain an indicator

Q3. What solution will the volumetric flask contain? Is the concentration of the solution known or unknown? Does this solution contain an indicator? 

Q4. You will perform a titration to determine the molar concentration of a NaOH solution. 

The balanced equation for the reaction is shown below:

 H2C2O4 + 2 NaOH → Na2C2O4 + 2 H2O

How many moles of NaOH will be required to neutralize 0.000835 moles of oxalic acid?

This answer is, from this balanced equation I can see that it takes two moles of NaOH for every one mole of Oxalic acid. Therefore, to nutralize 0.000835 moles of oxalic acid It will take twice as many moles of NaOH. 

0.000835 x 2mole NaOH/1mole oxalic acid = 0.00167 moles NaOH (5 significant)

and How to fill/write the from Q1 to Q3 ? 

Answer 1

You are doing a titration to solve for the molarity of the base, the NaOH. What is in the buret depends on what indicator you use for the experiment. In the buret you could have the base with known volume while keeping track of how much volume u are taking and using for the experiment. It is important to keep track of how much of the acid you use to combine with the base the NaOH in order to bring it to neutralization. The concentration of the acid solution is known. Otherwise how would you be able to work to solve for the concentration of the base? This solution will have an indicator depending on which indicator you use. If you decided to use phenylalanine, it will be clear in acidic solution and turns pink in basic solution.

In the erlenmeyer flask you will have the acid of know concentration of which you will be using a pipet or other instrument to use and extract the amounts of acid into the flask where the known volume of base, NaOH is. You will add drop by drop and watch for the solution to change colors due to the indicator. If you decided to use phenolphthalein common indicator that is clear in acid solution and turns pink in basic solution, then you will actually titrate in a way where u add a known volume of base in a flask, (even though you don't know its molarity because that is what u are solving for) add the indicator in this flask first beginning the titration, then titrate or keep adding drops of acid through the pipet, keeping track of how much is being added until the solution in the flask turns pink. This represents neutralization.

What is in the volumetric flask depends on which way you decide to titrate. If u are adding known molarity of acid to unknown molarity of base, the volumetric flask may hold the unknown molarity of the base, along with the ph indicator phenolphthalein.

If u know the concentration of the acid and it's volume, and the volume of the base (how much it took to combine with the acid) that it took to get the indicator to change from clear to pink then you can solve to find the molarity of the base.

For a 1 to 1 mole ratio: MVacid= MVbase,

Where M is for molarity and V is for volume. The molarity times the volume of the acid equals the molarity and volume of the base. Say you have 30 ml of acid. You can get the molarity if you know the moles because M= mol/L. So in the problem they give you .000835 mol for oxalic acid. So the molarity is .000835 mol/.030 L. You now have what you need for the acidic side. It took you 50ml to neutralize this acid with the base so now you must figure out how this corresponds to the moles of base NaOH. According to the equation there is one mole of acid to every 2 moles of base so you would have to double the moles of the acid to get the correct moles of the base in proportion. So .000835 x 2 = .00167, and that is the moles of the base. So what is the Molarity then of the base? .00167/.050L= .0334M would be the Molarity or concentration of the base NaOH.