Standardization of EDTA ~ A lab report

Title: Standardization of EDTA (ethylenediaminetetraacetic acid)

Objective: To standardize EDTA (ethylenediaminetetraacetic acid) solution with calcium nitrate.

Introduction: The concentration of a solution of EDTA was determines by standardising against a solution of Ca²⁺ prepared from the primary standard of Ca(NO₃)₂. EDTA is a versatile titrant that can be used for the analysis of virtually all metal ions. Although EDTA is the most commonly employed titrant for the complexation titrations involving metal ions, it cannot be used for direct analysis of anions or neutral ligands. Solutions of EDTA are prepared from the soluble disodium salt, Na₂H₂Y.2H₂O. Concentrations can be determined directly from the known mass of EDTA, however, for more accurate work, standardisation is accomplished by titrating against a solution made from the primary standard Ca(NO₃)₂.

The formation of a metal-EDTA is illustrated as follows;

Ca²⁺ (aq) + Y^4-(aq) ® CaY^2-(aq)

Where Y^4- is the shorthand notation for the chemical form of EDTA.

Apparatus and materials: calcium nitrate, 0.02M EDTA solution at pH 10, primary standard, NH₃-NH₄Cl buffer solution

Procedure:

1.        25cm³ of calcium nitrate solution and 2cm³ NH₃-NH₄Cl buffer solution in a conical flask was titrated against EDTA solution.
    2.   The volume of EDTA solution required to turn the red solution to blue was recorded.
    3.   The experiment was repeated.

Results:

Titration Number	Rough	1	2	3
Initial volume of burette (cm3)	3.0	9.0	14.0	9.0
Final volume of burette (cm3)	7.6	13.6	18.6	13.6
Titre volume (cm3)	4.6	4.6	4.6	4.6

 Discussion 
Calcium metal ion reacts with electron-pair donors to form coordination compounds.  The electron-pair donor is more generally called the ligand.  The ligand must have at least one pair of unshared electrons available for bond formation.  The type of bond formed is termed a covalent bond.  The number of covalent bonds a metal ion forms with the ligand is called its coordination number.  The resulting compound, or complex, formed between the calcium ion and EDTA may be electrically positive, negative or neutral.  Particularly stable complexes are formed when the ligand can form more than one covalent bond with the metal ion.  A class of such ligands are the so called chelating agents.  A complex is produced when a metal ion coordinates with two (or more) donor groups of a single ligand to form a five or six membered hetereocyclic ring with the metal ion.  A ligand that has a single electron-donor group is called a unidentate ligand, bidentate (2 electron-donor groups), tridentate (3 electron-donor groups) etc., chelating agent.

Aminopolycarboxylic acids are a group of compounds which form very stable chelates with many metal ions. Ethylenediaminetetra-acetic acid (EDTA) is one such aminopoly- carboxylic acid and is widely used to determine metal ions.  The structure of EDTA is shown in Figure 1 below:

A number of indicators are available for use in EDTA titration the most common is Eriochrome Black T.  Eriochrome Black T undergoes the following color transition at the equivalence point.

wine-red ® pure blue

Conclusion
EDTA (ethylenediaminetetraacetic acid) solution can be standardized with calcium   nitrate.

References: 
http://faculty.ccri.edu/aahughes/GenChemII/Lab%20Experiments/Calcium_Analysis_EDTA_Titration.pdf
Silberberg, M.S., Chemistry: The molecular nature of Matter and Change (5th edition, McGraw-Hill 2009)

Questions:

         Calculate the molarity of EDTA solution.

Molarity of Ca(NO₃)₂ = 0.4/164.08  ÷  500/1000
                                     = 4.876 × 10^-3

M₁V₁=M₂V₂

(4.876 ×10^-3×25)/1000=  (M2 ×4.6)/1000

M₂ = 0.0265 mol dm^-3

     Draw the complex structure of Ca²⁺-EDTA.

    

Fresh graduate experience

I am a Malaysian, graduated with a Chemistry background from University Tunku Abdul Rahman. Many who goes down the same path would eventually choose either to join the workforce or continue to further their education. I chose the former. I went to work in a company I used to intern before graduating.

I, like many other graduates out there, did not work in the field that I studied. Instead, I got involved in the corporate side of the science field. While I was working, I learnt a lot on time management, people management even how to handle myself during pressured moments. Nobody becomes an expert within a day but it pays if you were to focus on the task in hand and ask as many questions as possible within the first week of working. Believe it or not, you are hired not to ask questions but to solve problems. I was able to get the hang of the job within my 1st week of working. Granted, I used to intern there, so I knew where to get my information and how to access them.

Another thing I've learnt working in a multinational company is that observational skills can take you places. Observe your surrounding and look out for spaces you can use your talents in. Employers appreciate initiatives taken by fresh graduates as we sometimes see things from a different perspective. Beware of the saying " New broom sweeps well". So don't let that happen to you. Once you've started something, you better stick with it until the end.

While working, you would gain plenty soft skills that no amount of lecture classes can teach you. Make use of that opportunity and see how it can help you in your career advancement. I was able to make really good connections while working and as a result, it has shaped my future goals to what they are now.

Work, unlike school, isn't straightforward. You have to learn how to read between the lines and maintain neutral thoughts at all times, especially for fresh grads. Don't go Rambo at your first month, then flail the next. Take it slow and steady. Rome wasn't built in a day and you can't be a know-it-all in the first month. Listen to your peers, reduce office gossips and for god's sake, stay away from office politics. It does no good to anybody.

Stress happens to the most of us. One day, I found myself experiencing horrible migraines due to work stress. I was able to release all that by focusing on recreational activities. Its alright to have fun sometimes. The world isn't going to end if you make a mistake or two, just don't repeat those and you will do fine. These were the golden words my manager said to me when I was stressed at work.

I hope this small bit of information would help graduates to settle into their working lives.

Here is an image of the sea that I visited last month for relaxing purpose :) 

Being left out in a right world -Toastmasters Project Speech 1

Dear readers,

At the age of 24, I've finally joined a Toastmasters club. The nervousness I felt while doing my first speech is the same as I feel before making all my speeches.
I've managed to research on my topic title and got some info from the internet. As such, I'd welcome any advice to make my other speeches better and I'm also willing to guide new speakers to gain confidence in their project speeches.

Being Left out in a Right world

Hi everyone. Who in this room can possibly suggest what do these people (places Queen Elizabeth, Steve Jobs and Barack Obama on the board) have in common? Do you know that they have invited me to their club just by waving at the camera?

We belong in an exclusive minority group where everything that is right is wrong for us.

Fellow toastmasters and guest, you’ve heard it right. Let me give you a clue. I can’t use a regular scissors, never liked a binder note book and dislike sitting on a side foldable table. Yes people, I am left handed.

I have been left handed my entire life and it has influenced my behavior, thinking pattern and maybe even how I interact with people.

What seems normal for most people becomes a challenge for a person like me. Growing up around right handers is even tougher than you think.

School was hard. When I was a kid, my teachers and parents used to reprimand me for having an almost ineligible writing until I was about 6 years old. I had to contort myself so I could write on a right-handed desk. I struggled to keep my hand clean and often ended up with ink smudges on both the paper and my hand; writing in those spiral-bound notebooks is difficult, if not impossible, for lefties. I am always stumped by pen and pencils. Thank god for the computer! No more smudges.. thank you.

While at home, can openers, ice cream scoop and scissors are always hurting my hand. Until today I struggle with the can opener. My dad’s guitar will mock me every time I try to play it.

And when eating with groups, I have to fight to sit on the far left side of the table so I don’t bump the person next to me the entire time I’m eating.

I have often wondered if I really am that unique. With an estimated 10 percent of the population being left-handed, and almost 3 million people in the country being lefties, it’s not as rare as it feels.

Aside from feeling different myself, there seems to be a history of discrimination toward my left-handed comrades, embedded in language:

·        Some common English phrases portray the left as negative — such as a “left-handed” compliment.

·        In Latin, the word for left is “sinister,” which of course means evil in English.

·        The English word for left comes from the Old English word “lyft” meaning broken or weak.

One of the things that I have also heard my whole life is that I am clumsy and have no eye-hand coordination. But over the past few years, I’ve learnt that this is probably not due to a default in my natural abilities, but in having to use right-handed tools and items that are backward for me.

Given all this negativity surrounding us, it’s hard not to feel a little slighted. But there are some really great things about being left-handed.

We are right-brain dominated. Being “right brained” comes with all kinds of positives. We tend to be visual thinkers; we are more creative, have a greater imagination, are better at expressing feelings even non-verbally, and are great at daydreaming.

In fact, I am surprisingly capable of visualizing my chemistry classes just by listening to the lecture of the day. It is why I’ve always been fascinated by science. On the other hand, I can’t seem to watch Casper the friendly ghost until I was 14 because I was too scared at night thinking he might pop up in the bathroom.

On being creative, I’d like to think that my so called left handed character allows me to draw and write.

This is one of my drawings.

 I’ve used digital art mixed with pencil drawing in this photo. I admit, it’s no Picasso but at least it’s something to look at. This could also explain why I have an affinity to listen to songs of all genre and language… I love baroque, French blues and Hindi songs. From Linkin Park to Mozart’s Piano for Two I enjoy it all.

Lefties also seem to have a better chance of having a high IQ, or being considered a genius. Twenty percent of all Mensa members say they are left-handed, and among the famous “smart” lefties:  Charles Darwin, Albert Einstein, Marie Curie, and Isaac Newton.

One other thing I love about being a southpaw is that it is said that left handers are able to adjust to seeing underwater quicker. I may not be an amphibian or a sea creature, but that make me feel like I’ve got some sort of superpower. It helps me in my scuba diving too!

Lefties are better able to multitask. The theory is that being left-hand forces your brain to think more quickly. So we usually have an easier time dealing with a lot of unorganized information and are able to sort through it all.

Best part of all, there is a special day where all Left Handers celebrate our uniqueness on the 13^th of August every year.

However with all that said, we don’t really know if being right is better than left or vice versa. One thing I’ve learned is that I can live in a world where everything is for the right handed and I still thrive. So embrace your left hander counterparts and let’s start campaigning for left handed tables in schools shall we J