Chemistry Definition and 993 Threads

Two questions: 1. What tools and techniques are typically used to determine and plot spatial distributions of compounds--particularly organic ones--in interstellar dust? 2. Is it presently possible to determine distributions of compounds along arcs distant from the galactic center? If so, can...

Hi! I work in the movie business doing Special Effects. To create smoke for some effects we use "A+B Smoke." It is simply a mix of Acetic Acid (Part A) and Ammonium Hydroxide (Part B). However, the smoke effects is created when the VAPOURS of these 2 chemicals mix in the air. The MSDS Safety...

Homework Statement Hello! I would be grateful for your help on finding my mistake - somehow my answers are wrong compared to the answer from the book. Here is the exercise from a paragraph on gases (cumulative gas law, basics): Consider the reaction for the synthesis of nitric acid: 3NO2 + H2O...

Hi, I am just confused, regarding some definition above, I hope anybody can help explain differences. Does atoms resonate when subjected to some wave?

Homework Statement Homework EquationsThe Attempt at a Solution I have to explain why the boiling point generally increases from groups 14-16 but drops from 16-17, my answer is that every molecule in the the 17th group has only two atoms, meaning there are less protons in the molecule causing...

Homework Statement At T1 the root mean square speed (rms) of compound P is 485.2 m s-1 and at T2 the rms speed is 504.1 m s-1. Using this data and the fact that T2 – T1 = 24.0 °C, determine the molar mass of P in g mol-1. Homework Equations From problem statement you have: (3·R·T1/M)1/2 =...

I found this book while searching online for something and thought some people here might like to see it. It's an organic chemistry course from 1912. http://djm.cc/library/Principles_of_Organic_Chemistry_Norris_edited.pdf

Dear all, I want to know how to convert operator matrix when using Dirac Bra-Ket notation when it must be converted into a new dimension. I am currently working on transition dipole moment operator matrix D which I am going to use the following one: D = er Where e is charge of electron, r is...

Getting into NASA would be my greatest achievement. Presently, I am a chemistry graduating student. Do I need to study something to get qualified there? (I am not a US citizen)

Homework Statement So for my homework assignment in 'Materials Science and Engineering', We were given the following problem. 1. Li and Ra both are both BCC metals. For this problem assume they form a complete solid solution (even though the very large difference in their atomic size tell us...

So understand how to solve a problem using the equation: ΔS=Q/T But is there a conceptual explanation for why the equation works. And I'm not looking for a proof, but I simply want to understand why this equation should be intuitive. Thanks for your time!

1. Surfactant molecule is made from water-loving head and grease-loving tail (Figure 1). My question: How do we measure the cross-sectional area of the alkyl chain of surfactant? Do we measure it vertically (refer to GREEN DOUBLE ARROWS of Figure 1) or horizontally (refer to RED DOUBLE ARROWS of...

So I understand that enthalpy is energy. But what energy specifically? Is enthalpy heat energy? Is it the energy that bonds atoms together and that's why it can either be released or absorbed? Or is that what Gibbs free energy is? I'm trying to make sense of the equation: ΔG=ΔH-TΔS...

Homework Statement Data in the table were collected at 300 K for the following reaction: A(g) + B(g) → products Concentration of A 1.00 0.100 1.100 Concentration of B 0.100 0.100 1.00 Initial Rate (M/s) 1.29x10^-29 1.33x10^-30 1.30x10^-29...

Homework Statement I have the following task: A chemical reaction 2 A(g) <-> B(g) + C(g) has an equilibrium constant defined by: ln=0.8+ 1050/T−1,3.105/T² a) What is K at 400K? Calculate ΔrG0 In a volume of 5L you get 2 moles of A and 0.5 moles of B. Reaction still proceeds at 400K. Consider...

Homework Statement I did this lab on percentage of oxygen in potassium chlorate and I got a percent error of about 30%. I now need to find three reasons for error, and human error does not count. I think one could be that the masses used in calculating the theoretical percentage of oxygen were...

I'm taking my 3rd chem course and I was just wondering why do we use the Liter? Shouldn't we just use cm^3 on the instruments and use dm^3? I never got it.

Homework Statement Coursework topic - Chemistry in daily life Hi recently i am doing a coursework with topic " Chemistry in daily life" i am having trouble with where to start. The main purpose of this thread is asking for some chemistry experiment which involved in daily life. There are some...

I've only had a single semester of general chemistry but am in my third year of physics and will be taking general chemistry II this upcoming semester. In addition to the assigned text (Chemistry: A Molecular Approach, Tro) what I'm wondering is whether there are any textbooks that treat the...

Homework Statement State true or false: The boiling point of propanoic acid is less than that of n-butyl alcohol, an alcohol of comparable molecular weight. Homework EquationsThe Attempt at a Solution Is this just a question where you either know it or don't OR is there some argument based off...

Have been trying to better understand how batteries work. Forgive me if the question's naive. A half-reaction on one of the electrodes in a battery produces free electrons (for example) and consumes anions (or produces cations). I understand why, if there's an external wire for electrons to...

Homework Statement Topic : Idendification of different types of polymer Suggested materials : Plastic bottles or materials Sugeested methods of analysis : Volumetric analysis, Chromatography ,pH, Solvent extration, Distillation General purpose of project : To inculcate awareness on health and...

I just read what is hybridization its features and all. My textbook has a statement that hybrid orbital makes a stronger covalent bond than the old atomic orbitals but this can only be happen when hybrid orbital has less energy than the any of mixing orbitals. So is it true?

Homework Statement Which of the following will react with Br2 but not with I2? A OH− B SO3 2− C Fe2+ D Mn2+ Homework Equations N/A The Attempt at a Solution The answer given in the marking scheme is C, and I can't figure out how to come to that conclusion. Is it something to do with...

Hi everyone. So I have been learning about equilibrium recently in class... and suppose I have the following reaction: A(s) + B(aq) <-----> C(aq) + D(g) [Note: in parentheses, I indicate the state of my substances] So I was told recently that pulverizing my solid "A" would not change the...

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...

Homework Statement I did a lab on the experimental application of Hess's law. There were two experiments where a substance in a solution was dissolved and the temperatures were recorded. Then the standard heat of formation for the substance was calculated. The first experiment used MgO and HCL...

Dear PF Forum, I'm trying to understand antioxidant and free radicals. But I'm afraid that my chemistry is weak. Perhaps someone can help me with this picture? https://en.wikipedia.org/wiki/Hydrogen_peroxide This is Hydrogen Peroxide. Neutral. As much as I can surmise in this picture is... 1...

So I know that all the elements above 92 on the periodic table do not occur naturally, does that mean that we've discovered all the naturally occurring elements? Is it possible that there can be elements with a higher atomic number than 118 that we just haven't discovered yet in nature?

Dear PF Forum, Do anybody know the 'Wolfram Alpha' for chemistry? For example. If I enter: HCl + NaOH The website will produce something like HCl + NaOH -> NaCl + H2O (+ or - energy would be preferable) or if I enter: C6H12O6 + O2 The website will produce something like: Do you mean: C6H12O6 +...

Hi everybody, Have followed this forum for a year or so and decided it's about time to sign up. I have a couple of questions regarding my career. I'm currently a 2nd year Chemist, with interests in quantum/theoretical chemistry. My plans at the moment are leaning towards applying for a PhD...

I'm currently a sophomore in college studying computer science while minoring in both physics and chemistry. I constantly find myself debating whether I should or shouldn't major in physics instead of it being a minor. I already have quite a workload with computer science and I'm not sure how...

Hi! is there any microscope or images in which we can see how a matter reacts as it is heated? And how was it proved that when matter is heated their particules vibrate faster?. Tahnk you!

hi i am in the natural cosmetics industry and would like to have a scientific understanding of my craft. Accordingly do i study chemistry, organic chemistry or is there something else i should be looking at.many thks

is life a matter of constantly evolving chemistry?

I'm currently in my first year of a MSc in physical chemistry and in the process of deciding what topic to choose for my thesis (most likely starting around april). I think my personal interests lie more on the side of physics than chemistry (I have only become sure of it this year). My...

Sorry if this is in the wrong forum. (If you don't want to read my rant, just skip to the bottom paragraph.) I am currently majoring in chemistry at university, and I am graduating next semester. I like chemistry, unlike most people, but I'm a little different than my fellow undergraduate...

Hello, I'm currently enrolled in a 6 week General Chemistry 1 class that starts in January. The class meets about 5 hours a day Monday - Friday. I took the introductory chemistry course offered at my college this fall, and I was able to keep an A+ without much trouble. What can I do between now...

Is there a good book that contains various methods for qualitative analysis of organic compounds? (Like Tollens test for aldehydes).

I understand this topic has been brought up before, however there appears to be "truth" or "lies" and very little in between when it comes to explaining the Heisenberg Uncertainty Principle (HUP) to students of freshman chemistry. I'm teaching university general chemistry to students who've had...

I have searched the forums for this thread and have read several threads but I still have a few unanswered questions. Which major will involve more of the interactions between subatomic particles? Right now, chemistry is very interesting to me because it deals a lot with the interactions of the...

I am a professional math and science tutor, primarily focused on math and physics. I used to tutor organic chemistry but gave it up because I didn't want to study orgo an hour per week for the rest of my life. I like general chemistry and have no trouble with most topics, but the way of...

Good evening, I'm a student in my last year of high school and I'm still not sure about what I'd want to study later at University. I'm sure I want to do something with science but I am hesitating between chemistry and physics. I think I'm more interested in physics but am afraid it is going to...

Homework Statement Compute the average number of molecular hits, per unit time, experienced by a square inch of surface exposed to air, under normal conditions. Assume air is a mixture composed of 80% N2, 20% O2, both of which are assumed to be ideal gases. You will have to perform angular...

Hi, I enjoy both chemistry and physics, then perhaps wish to combine my interest and pursue it in a single career... Is that possible? Thanks in advance

Q1. Why do simple molecular substances tend to be insoluble in water? Q2. Molecular substances are often soluble in organic solvents. Homework EquationsThe Attempt at a Solution [/B] A1. Water molecules have strong intermolecular attractions between them. In order for a substance to...

I don't need help with the actual question, I just wanted to know if anyone else thinks there's an issue with this question of it it's just me. I've spoke to my tutor and he's confirmed what I need to do so I'm fine on that front, but I was curious if I'm just interpreting the wording...

What is the difference between physics and chemistry? I asked my Science teacher (who teaches Physics in senior years) and he said that chemistry was basically applied physics.

Homework Statement In a flame test lab, where different unknown substances are heated and the identity of the substance is determined by the color emitted, what can be some sources of error? Homework Equations n/a The Attempt at a Solution I need three sources of error, and so far I have...

Homework Statement When figuring out the product from a reaction using single replacement type of a reaction, we believe we understand what the elements and compounds will be produced but can't figure out how the subscripts are calculated/determined in some examples. #1 ZnS + O2 ---> ZnO + S...