1. ### Chemistry Ionic equilibrium titration

I got a answer by equation the moles i took the n factor of oxalic acid as 2 and the naoh solution came out to be 2M but i got an answer of 4grams but the answer given is 2 grams am i correct ??
2. ### Iodine number

1/ iodine stock solution: mixed 2,5424 g I2 and 24,1525 g KI and made up to 100 ml with water 2/ 150 mg active carbon is mixed with 12,5 ml jodine solution from point 1 / 3/ At equilibrium were performed filtration and titration with 10 ml of the filtrate with a volumetric solution Na2S2O3...
3. ### Chemistry Lab Titration curve calculations

Homework Statement Homework Equations The Attempt at a Solution I don’t have a clue on how to do the calculations. I know the equivalency point is at the steepest part of the derivative graph. Please don’t say just figure it out, I truly need help. I haven’t learned titrations in lecture...
4. ### Chemistry How do you calculate moles to neutralise oxalic acid?

Homework Statement calculate the number of moles of potassium manganate required to neutralise oxalic acid. 2KMn)4- + 5H2C2O42-+ 16H+ --> 2Mn2+ + 10CO2 + H2O Homework Equations n = c x V n= m/Ar The Attempt at a Solution Moles of oxalic acid = 5x10-4 Volumeol of KMnO4 = 0.01085dm-3...
5. ### Redox titration

Cl2(g) + 2I–(aq) -->I2(aq) + 2Cl–(aq) (reaction 1) [2S2O3^(2-)(aq) + I2(aq) --> S4O6(2-)(aq) + 2I–(aq) (reaction 2) Why isn't n(I2)(reaction 2)=2n(S2O3^(2-))(reaction 2). I don't see why this is wrong. <edit: remove size and italics>
6. ### Chemistry Why moles of (S2O3 2-) is equal to mol of ( MnO4-) times 5

Homework Statement The ratio of KMnO4 to I2 is given by 2 MnO4 - + 16 H+ + 10 I - ⇌ 2 Mn2+ + 5 I2 + 8 H2O the ratio is 2:5 - The ratio of I2 to S2O3 2- is given by 1 I2 + 2 S2O32- ⇌ 2 I-+ S4O5 2- the ratio is 1:2 therefore n(S2O3 2- ) = n(MnO4 - ) x 5 Homework Equations Why the mole of...
7. ### Determination of an Acid (Monoprotic) by Titration Lab

I tried looking for my unknown (209.70 g/mol) online and couldn't find it. The closest I found were H4O7V2(217.907 g/mol) and HCl2I(198.819 g/mol), but I know I am correct to a 2.7% accuracy. What other lists can I use to solve this?
8. T

### Stoichiometry and Titration

Homework Statement Joshua has been gold panning and extracts a mixture of silicate stone and shiny gold-like particles. However Nkosi says these are Fool's Gold i.e Chalcopyrities (Cu Fe S2). They decide to find out how much iron is in the sample by: -Grinding a 30.00g sample to a fine powder...
9. N

### At what temperature does citric acid decay?

I am currently performing a school experiment in which I am testing when citric acid decays. We are juicing lemons, filtering them to get a higher concentration of citric acid, placing them in water baths from 10 to 90 degrees Celsius and then titrating them against one mole of sodium hydroxide...
10. ### A problem in titration

Homework Statement :[/B] The percentage of copper in a Copper (II) salt can be determined by using a thiosulphate titration. 0.305g of a copper (II) salt was dissolved in water and added to an excess of KI solution liberating Iodine. The liberated Iodine required 24.5 ##dm^3## of a 0.1 mole...
11. ### A question in double titration

Homework Statement :[/B] A mixed solution of KOH and sodium carbonate required 15ml of (N/20) HCl solution when titrated with phenolphthalein indicator. But the same amount of solution, when titrated with methyl orange as an indicator, required 25ml of the same HCl. The amount of KOH in the...
12. ### A problem in Redox Titrations (Kjeldhal's Method)

Homework Statement :[/B] 1.08g of ##NH_4 Cl## is boiled with 62ml ##\frac {N}{2}## ##NaOH## to expel ##NH_3## completely. 44ml of ##\frac {N}{4}## ##HCl## is required to neutralise the excess alkali. Calculate the percentage of ##NH_3 ## in ##NH_4 Cl##. Answer given: 31.5% Homework Equations...
13. ### What is the difference between valence factor and n-factor?

What is the difference between valence factor and n-factor for oxidants and reductants? Take ##H_2O_2## as an example. What is the difference between the n-factor and valence factor for this compound? Also, how do I find the n-factor for any oxidant or reductant?
14. ### Titration exam question

1. The problem statement, "all variables and given/known data A solution of nitric acid, HNO3, of concentration 100 g dm-3, can be used to artificially age wood. A sample of nitric acid was tested by pipetting 10.00 cm3 of the acid into a 250 cm3 volumetric flask and filled up with deionised...
15. ### Preparation of murexide indicator for Ca measurement

I want to prepare murexide indicator for Ca measurement using EDTA titrimetric method. I am following the procedure set by the American Public Health Association (APHA), however, I only have murexide diluted with K2SO4 (1:250). I want to know if I can use this as a substitute, and if yes, how...
16. ### Understanding the chemistry behind: Why O2 and not I2?

We were doing O2 estimation by Winkler's method The procedure and reactions involved in this experiment are: Carefully fill a 300-mL glass stoppered bottle brim-full with sample water. Immediately add 2mL of manganese sulfate to the collection bottle. Add 2 mL of alkali-iodide reagent (NaOH +...
17. ### Magnesium salt of EDTA is the same as EDTA-2NaMg?

I was reading through the standard complexiometric method of determining hardness in water, and the procedure mentioned the use of the magnesium salt of EDTA. I looked up online to purchase this reagent but all I could find was disodium magnesium salt of EDTA. Are they one and the same? Thanks!
18. ### Calculation of O2 dissolved in water

We were measuring the amount of O2 dissolved in water by Winkler's method. Here's a link to the procedure and reactions: http://file:///C:/Users/SANJUKTA/Desktop/Downloads/Capture.PNG [Broken] http://dropcanvas.com/6su7m/1 (The same is attached to this post) We had to use this formula: c(O2)...

Hey guys! So I have this chemistry problem which I'm finding very difficult. QUESTION: You have an unknown triprotic acid, H3X, and have titrated it with 22.53mL of NaOH. The pH of the unknown solution is 2.04 and the concentration is 48.028g/2L. While the concentration of the NaOH is...
20. ### Calculating the Ksp of Calcium hydroxide at room temp

Homework Statement I conducted a titration experiment in which 0.1g of KHP was dissolved in 50mL of distilled water and placed in an Erlenmeyer flask. I filtered a Ca(OH)2 solution (that was left out open on the lab benches for us to use) and put that into the burette and titrated. Ultimately...
21. ### Determine percentage of iron(II) and iron(III) in a solution

Hi I am stuck on the following question. Outline a plan of an experiment to determine the percentage of iron present as iron(III) in a solution containing Fe3+(aq) and Fe2+(aq) ions. You are provided with zinc, a standard solution of potassium dichromate(VI) and dilute sulphuric acid. Zinc can...
22. ### Volume strength of H2O2 using iodometric titration

Homework Statement To a 25ml H2O2 solution, excess acidified solution of potassium iodide is added. The libereated iodine required 20ml of 0.3N sodium thiosulphate solution. Calculate the volume strength of H2O2. Homework Equations Normality = n-factor × Molarity Volume strength = Molarity ×...
23. ### Titration error affecting the PH of the endpoint

Homework Statement Hi everyone. 1) If I perform a titration with a buret not rinsed in the titrant, then how will the pH of the endpoint be affected? 2) Also, if the volumetric pipet used to measure the analyte is not rinsed with the analyte, how will that affect the pH of the endpoint...
24. ### Question about acid and base indicators

Homework Statement Methyl red has the following structure [not listed here on this post] Ka = 5.0 * 10 E -5 It undergoes a color change from red to yellow as a solution gets more basic. Calculate an approximate pH range for which the methyl red is useful. What is the color change and the...
25. ### Needing help identifying a salt.

So I recently did a titration lab with a monoprotic acid and sodium hydroxide. After using stochiometric ratios I found the molar mass to be around 175g/mol. It is possible I have a huge percentage error, but can anyone think of an acid that is monoprotic and is within the range of that molar...
26. ### Buffer action and titration

If H2A2+ is being titrated with NaOH, a buffer forms. The processes taking place are equilibrium between H2A2+ and HA+ ions, autoprotolysis of water and reaction of OH- ions with H2A2+ ions. As NaOH is added, the concentration of acid tends to decrease but because of the equilibrium ##H_2A^{2+}...
27. ### Titration of amino acid with strong base

Homework Statement An amino acid H2N-CHR-COOH e its as a dipolar ion: +H3N-CHR-COO-. In strongly acidic medium, it takes H+ to form conjugate acid +H3N-CHR-COOH 50ml solution of conjugate acid required 30ml of 0.1M NaOH to completely convert into dipolar ion. The pH of solution during titration...
28. ### PH of a titration

Homework Statement A 0.551 L solution of 1.37 M sulfurous acid (Ka1 = 1.5e-2 and Ka2 = 1.0e-7) is titrated with 1.65 M NaOH. What will the pH of the solution be when 0.7549 L of the NaOH has been added? The answer is 7.27. Homework Equations -log(H+)=pH pH = pKa + log(salt/acid) The Attempt...
29. ### What is the equivalence point on this graph?

I am attempting to do a lab that requires the determination of an unknown diprotic acid using a titration curve. I have graphed my data but I am unsure what point to use as my eq. point. In my lab manual it says I may use the second or first eq. point but the second is often clearer. I am not...
30. ### Finding mass of acetyl salicylic acid in aspirin tablet

Homework Statement 25 cm3 of 1M NaOH added to an aspirin tablet. 25cm3 of distilled water also added. Mixture heated for 10 mins. Hydrolysed solution and washings transferred to a 250 cm3 conical flask and made up to the mark (250cm3). 25 cm3 of the hydrolysed solution is titrated against 0.1M...