The branch of chemistry concerned with identifying and quantifying the chemical constituents of matter.

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Software for ion speciation of Ni(II)?

How can I make an ion speciation curve of $\ce{Ni^{2+}}$ in a base solution $\ce{NaOH}$? Does there exists a software that does that or a tutorial? I tried using HYSS2009, but documentation is no good ...
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36 views

The behaviour of Ag3PO4 in solution

To a 1L flask, we add $4.1900\mathrm{g}$ ($0.01001\ \mathrm{moles}$) of $\ce{Ag3PO4}$, then fill it up with water. Knowing the following constants, we are asked to find the concentration of all ...
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1answer
12 views

Quantitative Analysis of Urea in aq. solution

What would be a good way to assay Urea in aq. solution? The test doesn't need to be super accurate. 1% accuracy is fine. But it needs to be relatively fast & robust to carry out. NaHCO3 is a ...
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17 views

exercise qualitative analytical chemistry [on hold]

Many precipitates of carbonates, sulfates and sulfides may be dissolved by addition of acids. Based on this statement, justify why this occurs.
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Apparent solubility of Ag2C2O4 in a buffer solution

We take the following quantities and mix them together: $20\mathrm{mL}$ solution of $\ce{AgNO3}$ $0.001 \frac{\mathrm{moles}}{\mathrm{dm^3}}$ $20\mathrm{mL}$ solution of $\ce{H2C2O4}$ ...
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1answer
36 views

What is the process to solve this disproportionation REDOX question?

I know how to solve REDOX reactions, but this one is really confusing me, since I can't really write half reactions for it. $\ce{ClO3- -> Cl2 + O2}$ the answer is apparently $\ce{2H+ + 2ClO3- ...
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16 views

How does pH level change the concentration of dissolved oxygen (DO) in sea water?

I am planning to investigate the relationship between $\mathrm{pH}$ and dissolved oxygen. I would like to have a reason without taking in account the plants, animals and decomposer roles. I want to ...
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9 views

electrophoretic mobility and EOF

I'm currently studying about capillary electrophoresis. I'm quite confuse about mobility of electrophoretic and EOF. Why does negative charge has greater electrophoresis mobility than EOF and ...
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23 views

How to test if white powder is lime fertilizer?

I found two buckets (white and black) containing a very light grey powder in the basement. The label is partially removed, but it probably originally contained lime fertilizer. However, I am not sure ...
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2answers
90 views

Remove salt from dirt

I have a mixture that contains out of dirt/sand and salt. I want to extract and measure the salt. What would be the best way to extract the salt from this mixture? P.s not sure if this is the ...
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23 views

Method and Tips for Inorganic Qualitative Analysis

In a few weeks time I will be doing a inorganic qualitative analysis test which is very pressed for time (a majority of people don't finish). The form of the test is most likely going to be that there ...
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37 views

What reaction distinguishes glycerol and tert-butanol?

What reaction can we use to distinguish between glycerol and tert-butanol in laboratory conditions? I know alcohols exhibit the following: deprotonation, yielding an alcoholate salt reaction with a ...
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14 views

Why -COOH group on the Graphene quantum dots have much more affinity with Hg(II) than other ions?

Could anybody explain why the COOH group around the edge of the GQDs have much more affinity with Hg(II) than others?
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17 views

What type of standard for HPLC capsaicin quantification?

I'm wondering which type of standard would be the most suitable for the quantitative analysis of capsaicin (8-Methyl-N-vanillyl-trans-6-nonenamide) containing products? Sigma offers the following ...
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28 views

Simplified Chromatography - will this work?

I am interested to separate a sample matrix via a method very similar to chromatography. The reason I am asking about this is because I am planning to integrate this method with my SERS application. ...
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1answer
29 views

Correct term/word for bias in calculations?

I ran an experiment recently and made several approximations in the calculations that led to the results being around 2 orders of magnitude less then the literature values. I will be re-doing the ...
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21 views

What means can be used to distinguish different sorts of plastic?

So, different sorts of plastic usually have different marks on them (the resin identification code, like 1/PET for polyethylene terephthalate etc). However, sometimes one can encounter a piece of ...
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32 views

Can we make chromatography less troublesome?

Thin Layer Chromatography is a very powerful method in analytical chemistry for separating complicated chemical matrices. As an engineer, I am interested to build device capable of automating TLC ...
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24 views

E / Z Isomers GC peaks for identification; Would GC-MS help?

Does a GC analysis typically seperate E / Z isomers? I'm reading a paper that confirms that the product it synthesized was indeed the (E,E) isomer by coinjecting a standard sample on the GC. My ...
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20 views

What is the difference between column chromatography and a fractionation column?

I'm a chemistry student doing research in a biotech lab. I'm doing the chemistry portion of the project. It is time to write the methods for my paper and I'm confused on what the proper term for what ...
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1answer
57 views

In NMR Spectroscopy why use absorption and dispersion components of the FID spectrum rather than magnitude and phase?

In chapter 4 of Dr James Keeler's book 'Understanding NMR spectroscopy' (http://www-keeler.ch.cam.ac.uk/lectures/Irvine/chapter4.pdf) he explains how to calculate the expected spectrum of a FID ...
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1answer
73 views

Minerals in water solidify when heated?

Is it possible for minerals in drinking water to solidify when high temperatures are applied? The minerals in mind are: iron, copper, aluminum, magnesium. Background: I have small, brittle, darkish ...
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2answers
131 views

The mathematical condition for a complete complexation reaction

I'm being asked to find the volume of a $\ce{NH3}$ solution ($0.1\ \mathrm{M}$) to be added to $10\ \mathrm{mL}$ of a $\ce{AgNO3}$ solution ($0.1\ \mathrm{M}$) to assure the 'complete formation of ...
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62 views

How to estimate the concentration of OH that comes from just the autoprolysis of water in a basic solution?

In my analytical chemistry course, a question reads: What is the pH of a 0.10 M solution of THAM? Is it valid to neglect the autoprotolysis of water? Justify and explain your answer by estimating ...
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40 views

Is there any process to determine what elements a physical sample is made from?

I'm wondering if anyone knows of laboratory services that can analyze a sediment sample to tell what it's made of. Background: our drinking water has small black flakes appearing, and our city water ...
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1answer
42 views

GCMS Peak Identification: Online or Open Source / Free Programs?

Suppose I have a GCMS peak graph for a component, what are possible options to figure out what the molecule may be? Any tips about good software that will do this? I do know that for many compounds ...
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12 views

White precipitate observed in bromelain assay

After adding TCA to bromelain assay, I was unable to measure absorbance for 2 days (which is not suppose to happen though), and now it has formed some white colour precipitate, and I vaguely remember ...
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20 views

concentration of silver nitrate solution [closed]

I have 300 litres of silver nitrate solution. From this I took 100ml solution. I need to get the concentration of this 300 litres of solution by titrating the 100 ml against pottassium chloride ...
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1answer
36 views

Formation of water vapour during combustion

When we burn fuel, water vapour is produced because hydrogen is burnt as well. But since the vapour is in gaseous state already, it shouldn't steal any heat from fuel gases, should it?
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44 views

Issues with visually determining the end point in redox titrations

This month, I have to practice redox and acid-base titrations for the Chemistry Olympiad, using reagents like: Sodium Thiosulfate ($Na_2 S_2 O_3$), Potassium Permanganate ($K_2 MnO_4$), Potassium ...
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1answer
44 views

Calcium sulphate soluble in water

In the volumetric estimation of calcium in a given solution as calcium oxalate.. We convert the calcium oxalate to oxalic acid by dissolving the former in hot (~70 °C) 2 N sulphuric acid solution. ...
3
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1answer
90 views

Analysis of multiple spectra to determine an unknown structure

I've been trying to solve the structure of a molecule from a 13C and proton NMR as well as a MS spectrum, but I've been stumped, I've been staring at it for a while with no improvement. I've attached ...
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28 views

How to calculate pH? [closed]

Could you please help me or give me any source to understand the calculation of pH in acid and bases both strong and weak ? And pH in salt solutions ?
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105 views

number of significant figures in 5*5.364?

How many significant figures should be present in the answer of $5\times 5.364$? 1) Addition rule: The result cannot have more digits to the right of the decimal point than either of the ...
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1answer
114 views

Which method can be used to determine the pKa of an acid-base indicator like bromothymol blue?

I have a question about how one would determine the pKa of an acid-base indicator such as bromothymol blue. I know that spectrophotometric analysis is one option, but is it possible to perform an ...
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2answers
35 views

What type of analytical chemistry (such as spectroscopy) is suitable for high resolution air analysis

I want to find some type of analytical chemistry method, such as spectroscopy, that is capable of analysis the chemical composition of air. If it can be used for high resolution analysis would be ...
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12 views

pH of a solution 1) disregarding activity and 2) using ionic activity coefficients [closed]

A weak acid with MW= 356 and pKa= 2.76 is dissolved in an isotonic NaCl solution to make a 3% w/v solution. What is the pH of this solution 1) disregarding activity and 2) using activity coefficients ...
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1answer
37 views

Why does more acetic acid require more sodium hydroxide in order to be neutralized

I was recently titrating sodium hydroxide against vinegar and based off my results i realised that the vinegars with a higher concentration of acetic acid required more sodium hydroxide in order to ...
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1answer
72 views

How to determine the molecular formula of a compound given percentages of the elements?

If the molecular mass of a compound is given as 'm' and it consists of two elements 'A' and 'B'. The compound it composed of x% of 'A' and y% of 'B'. How do I find the molecular formula of the ...
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34 views

How to find formula weight and identity of an unknown compound?

What is the formula weight and identity of the unknown copper compound? mass of precipitated copper = $0.539\rm~ g $ mass of copper compound = $1.446\rm~g $ I was able to algebraically make a formula ...
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1answer
44 views

the number of significant figures

An electronic balance was used to determine that a sample has a mass of 9.00060 g. If the balance's precision is ± 1 mg, what is the correct number of significant figures for this measurement? ...
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1answer
49 views

Question about DNP derivatives of amino acids (specifically epsilon-DNP-lysine)

I have a pretty basic biochemistry question but am having trouble finding the answer to it: Normally, DNFB (dinitrofluorobenzene, or 1-fluoro-2,4-dinitrobenzene to be exact) reacts with just the ...
5
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1answer
45 views

Comparing Methods of Determination of Dissolved Oxygen Content in Water Sample

I am currently doing an IB Chemistry Individual Investigation on dissolved oxygen in water samples by using Winkler method. However, my teacher suggested that I have to use oxygen probe as a standard ...
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32 views

SERS Gold nanoparticles performing poorly in organic solvents?

We have been working with some organic solvents lately and noticed a sharp decrease in surface-enhanced Raman spectroscopy (SERS) performance from our gold nanoparticles deposited in an organic ...
3
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1answer
61 views

Chemical test for ferrous ions

I have a reference sheet for inorganic analysis which says that the confirmatory test for ferrous ions is as follows: "Make a solution of the given salt (whose cation is to identified) and add ...
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0answers
32 views

Qualititative inorganic analysis

Why is it that a specific order is followed while performing qualitative inorganic analysis? I mean, why are we told to first test for the anion in the given salt (and there is an order to be followed ...
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1answer
57 views

How to easily distinguish salts physically? Edit

I have basically 12 salts to identify in exams. They are *** Ammonium Carbonate, Ammonium Sulphate, Ammonium chloride, Aluminium Nitrate , Aluminium Sulphate, Barium chloride, Calcium Carbonate, ...
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An alternate purification process for sugar separation form bee honey?

Bee honey contains 75% sugars (Fructose, Glucose, Maltose, Sucrose and others), some water and low amount of different compounds (up to 5%) Wiki. Basic purification is done by addition of phosphoric ...
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1answer
34 views

What is the concentration of Ca2 in this solution if [OH–]? [closed]

Solid hydroxylapatite is dissolved in water to form a saturated solution. What is the concentration of Ca2 in this solution if [OH–] is somehow fixed at 2.70 × 10-6 M?
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2answers
46 views

What is the lowest mass measurable using a 4 decimal point analytical balance?

I think it is 1 mg, but I've heard people saying 0.1 mg. As 0.1 mg = 0.0001 g, which is the uncertain digit, I think such a measurement is not reliable at all. Any opinions ? Thanks.