Chemistry is the scientific study of the properties and behavior of matter. It is a natural science that covers the elements that make up matter to the compounds composed of atoms, molecules and ions: their composition, structure, properties, behavior and the changes they undergo during a reaction with other substances.In the scope of its subject, chemistry occupies an intermediate position between physics and biology. It is sometimes called the central science because it provides a foundation for understanding both basic and applied scientific disciplines at a fundamental level. For example, chemistry explains aspects of plant chemistry (botany), the formation of igneous rocks (geology), how atmospheric ozone is formed and how environmental pollutants are degraded (ecology), the properties of the soil on the moon (cosmochemistry), how medications work (pharmacology), and how to collect DNA evidence at a crime scene (forensics).
Chemistry addresses topics such as how atoms and molecules interact via chemical bonds to form new chemical compounds. There are two types of chemical bonds: 1. primary chemical bonds e.g covalent bonds, in which atoms share one or more electron(s); ionic bonds, in which an atom donates one or more electrons to another atom to produce ions (cations and anions); metallic bonds and 2. secondary chemical bonds e.g. hydrogen bonds; Van der Waals force bonds, ion-ion interaction, ion-dipole interaction etc.
Homework Statement
How many milliliters of Cl2 gas, measured at 28.0 °C and 750 torr, are needed to react with 18.5 mL of 0.173 M NaI if the I- is oxidized to IO3- and the Cl2 is reduced to Cl-?
Homework Equations
The Attempt at a Solution
So the molar mass is .0030906 mol NaI...
The problem is that 'my' solution is at variance with the solution provided for the question in the solutions manual that accompanies the textbook I am using.
Homework Statement
"A 14.1-mL sample of 0.996 M NaOH is mixed with
32.3 mL of 0.905 M HCl in a coffee-cup calorimeter (see Section...
Homework Statement
Geologists are able to calculate ages of rock samples through measurements of certain isotopic rations combined with known radioactive decay rates (all such decays being considered to adhere to 1st order kinetic rate laws). Two such processes leading to stable isotopes are...
Hey all,
Lately I've been distracted by a big decision. I am a chemistry major at a small liberal arts college. And boy do I love chemistry! Doing research in the lab is really fun, and I enjoy thinking about chemical phenomena. But I feel like I've been cheating on chemistry lately. I've...
I will be graduating with my B.S. in physical chemistry after this quarter and would subsequently like to attend graduate school in physics. I'm not really looking for a "can I go to graduate school in physics with x degree" type answer, but more something along the lines of personal experience...
Homework Statement
A solution consist of Co+2 and Ni+2 ion in which excess KCN is added and in the resulting solution alkaline Br2 was added. The solution finally consist of which species?
The Attempt at a Solution
I guess some complex would be formed but how to exactly find out the...
I am a 20 year old Chemistry major who is currently finishing up his junior year of college. My initial plan was to graduate with a Chemistry BA and then proceed to apply to medical school. However, after taking physics non-calc based 1 & 2 I remembered how much I enjoy the physics. I am...
Hi all,
Thank you in advance for your responses. I recently graduated with my bachelors in Chemistry (December) and was gainfully employed immediately thereafter (Early January) by company X. I am seeking advice as to the order in which I should pursue certifications and post Bachelor degrees...
Homework Statement
Find the pH of 1.0 x 10^{-7} M H_{2}S solution.
Homework Equations
We can take three approaches to this problem, one which is mathematically and chemically correct, one mathematically correct but not necessarily chemically correct, and one which is unequivolcally wrong...
entrepreneurship in the field of chemistry
Homework Statement
I have to write an essay this year in my chemistry class on some topic related to applications of entrepreneurship in the field of chemistry. It has to be 5 pages long (double spaced), but i am struggling to find topics related to...
Hey guys,
I am currently finishing up my freshman year as a chemical engineer and I have seen many threads asking if they should go from chemistry to chemE, but never the other way around. Personally, I like research. I think it would be great to actively do research and try to discover...
Hi, thanks for checking out this thread.
I'm really having a problem with the question because I don't have any foundation.
If you could, would you:
Explain what exactly is going on? Is this an endothermic or exothermic reaction?
What are colligative properties, and what do they have to...
In this post i want to discuss good chemistry textbooks vs. bad chemistry textbooks and I'd like some help finding a good General chemistry textbook for university - Undergraduate level.
What Is a good introductory chemistry textbook?
So i finally found a book in organic chemistry which...
Homework Statement
Why do bases lose all of their hydroxides at once?Homework Equations
N/A
The Attempt at a Solution
Polyprotic acids lose their hydrogen atoms in a step-wise fashion, but bases with multiple hydroxides do not do this. I'm not quiet sure why this occurs, but I think that...
Homework Statement
Given 2C2H6 \rightarrow2C2H4(g) 2H2(G) \Delta H=-64.2kJ
\Delta H for the reaction of 6.000g of C2H6(g) to givev C2H4(g) andH2(g) is
Homework Equations
\Delta H = \Sigma products - \Sigma reactants
q=ct
keeping the units
The enthalpies are not given and are not to be looked...
What is the difference between "Gas Phase Ion Chemistry" and "Plasma Chemistry"? If one wants to learn about the ionization and dissociation processes of hydrogen gas are either of theses fields appropriate to study?
1. Consider a particle of mass m in a cubic (3-dimensional) box with V(x,y,z) = 0 for 0 < x < L, 0 < y < L, and 0 < z < L and V(x,y,z) = ∞elsewhere. Is 1/\sqrt{2} * (ψ(1,1,5)+ψ(3,3,3)) an eigenfunction of the Hamiltonian for this system? If so, what is the eigenvalue? Explain your reasoning
2...
I was reading this article from Wikipedia on resonance structures:
http://en.wikipedia.org/wiki/Resonance_(chemistry )
What I do not understand is, what is meant by potential energy in terms of chemistry? In physics, potential energy is defined by location in a force field. What is it that...
Hey everyone, I was hoping someone could point me towards a good General Chemistry textbook. I just finished General Chemistry I last semester, and I'm taking part II next semester. We didn't have a required text for the class (nor did we even really need one), but I want to get a good...
'Relativistic Quantum Chemistry' -- Say whut?
So I just found out that one of my co-workers (well, someone who works in the same building with me but not directly with me) has a PhD in this field, he took like the last two weeks off for Christmas vacation, but when he explained to me some of...
Hi. Tomorrow I am taking the ACS General Chem 1 exam as a final. It's supposed to be 40 questions but I heard it is incredibly difficult. I currently have a 95% in my class and need to get at least 24 out of 40 to get an A for the semester. The problem is that my class was so easy (we got to use...
In my country, entrance exams for colleges include topics in physics, chemistry and math. For someone who takes computer science as his branch, why is the student being tested in physics and chemistry?
Being knowledgeable in physics and chemistry is useless if someone takes computer science...
Good evening guys,
I have to decide whether to purchase Atkins or Levine for my physical chemistry learning? Personal experiences with the textbooks are encouraged.
Hello,
Please help me with the following problem.
Homework Statement
0.10 Liter of Methane (CH4) gas, at a temperature of 25C and pressure of 744mmHg, react with Oxygen (O2) gas, at constant pressure.
The heat released during the process is then transferred to an "ice...
Hi! This is my first post in this forum, hopefully I will get some guidance :)
Long story short, I am pretty much set in doing a double major in Chemistry and Mathematics.
The thing is, I'm really having trouble choosing between Applied Maths and Pure Maths major.
I have completed my...
Hi,
I'm confused at why cathodes are the positive terminal in chemistry but appear to be the negative terminal in physics. I hope someone can clear this up for me.
Definitions:
Anode: An anode is an electrode through which conventional current flows into a polarized electrical device...
So today a friend came up to me and said getting a chemistry degree is not worth it with engineering and I would you guys here at the physics forum to show me the reality of the degree situation.
First let me start of my university dose the 3+2 two degree engineering program with Columbia, so...
I have attached a file of the alcohol I need to synthesize and my futile attempt... I was thinking of using a hydration reaction to make the alcohol from the alkyne group. So basically I would mix the alkyne group with H2O and some how produce the alcohol group.
Am I heading in the right...
Homework Statement
The Reaction; 2NO(g) + Cl2 (g) → 2NOCl (g)
Is second order in NO and first order in Cl2. Five moles of nitric oxide and two moles of Cl2 were brought together in a volume of 2dm3 and initial rate was 2.4x10-3 moldm-3sec-1. What will be the rate when one half of the...
Hi,
I'm an undergrad student in India doing a BS program. I've studied all the subjects for past one and a half years and now have to choose one to major in. I'm really torn between physics and chemistry.
Unlike many other people I have no firm idea about what I want to do in future and is...
these are the topics which i want:
atomic structure
periodic classification of elements
s,p,d,f blocks
co-ordination and bio co-ordination compounds
radioactivity
solid state
chemical equilibrium
chemical kinetics
thermodynamics
surface chemistry
electrochemistry
stereochemistry...
I'm taking a course in chemistry and I need some help, I have some questions :
1.Why do ions, strong acids,bases etc. conduct electricity well ?
2.In the periodic table, are the masses of atoms in amu or grams? what's the difference? and why is Carbon 14 the standard ? why do we need a...
Simple chemistry questions -- creating particle beams...
I'm new to chemistry and trying to understand this page http://www.chemguide.co.uk/atoms/properties/. I'm about to ask some very silly questions :rolleyes:
It shows two examples of what will happen if a beam of protons, neutrons and...
I've got a project I'm interested in.
Essentially its modifying a melamine foam so its thermal conductivity is at least halved. Was thinking some type of buckyball filler in the matrix might be a ticket. However someone pointed out it maybe a worry about how it would affect the cell...
Homework Statement
I have to calculate the Ksp value for calcium hydroxide from experimental data. We titrated 10.00 mL of saturated Ca(OH)2 aqueous solution with 11.00 mL of 0.01607 M EDTA.
Homework Equations
The Ksp formula is given in my manual as [Ca^2+]*[OH^-]^2
The Attempt at...
Chemistry A, real simple for most people. "Mol" problems.
Homework Statement
Hello, first I'd like to say thank you to this community as I have gotten a lot of help in the physics department before and is basically a big reason of me passing the class.
Now chemistry is here and I am...
Simple chemistry, need help with "mol" and so forth. Problems ITT.
Hello, first I'd like to say thank you to this community as I have gotten a lot of help in the physics department before and is basically a big reason of me passing the class.
Now chemistry is here and I am having a little...
Chemistry Homework -- the empirical formula of crocetin
Homework Statement
Crocetin consists of elements carbon, hydrogen and oxygen. Determine the empirical formula of crocetin, if 1.00g of crocetin forms 2.68g of carbon dioxide and 0.657g of water when it undergoes complete combustion...
I am currently experiencing a stressful thought process about what to do when I get to college.
One of my interests is in chemistry. I like chemistry because I feel like it gives a power to make things you want and you can go in so man different directions with it. I especially like biochem...
Homework Statement
Let's say that i have a unknown weak acid.
I prepare 10mL of the weak acid diluted in 25mL of water.
I titrate the solution with NaOH. 7.37mL of NaOH was needed for a full titration.
Therefore, half-titration of this acid was 3.69mL.
I measure the pH of the solution with a...
If a polynomial equation is solved for multiple roots in a system of equilibria (e.g. calculating extent of a reaction, or solving for [H+] in a complicated acid-base system, to give two basic examples) how do we know which, among the roots, is the correct solution (e.g. the correct extent or...
lab report -- How to write better lab reports in chemistry?
Hi,
I get very grateful if you help me get exampler on lab reporter on chemistry. I just want to read them, how can you write a better way because I'm not erfaran on engliska.
Homework Statement
"1.79 g of a fuel was burned in the presence of oxygen. The fuel is a composite of 90% octane and 10% ethanol. Calculate the number of moles of this fuel that was burned."Homework Equations
Moles = Mass/Molar Mass
The Attempt at a Solution
90% of 1.79 g is 1.61 g. This was...
Homework Statement
consider the following reaction: 2H2O(i) <-> 2H2(g) + O2(g)
kc=7.3*10^-18 at 1000oC
The initial concentration of water in a reaction vessel is 0.055 mol/L. What is the equilibrium concentration of H2(g) at 1000oC?
Homework Equations
h20 h2...
So I am a chemistry major, but really like math and physics as well. I was wondering how necessary it would be to take quantum physics after taking two semesters of physical chemistry. I go to a small school and there aren't a host of physics classes, so quantum physics is the end of its road...
Hello...
I'm making elephant toothpaste for my chemistry project, where I'm using activated yeast+73 ml of water and soap+10 ml of hydrogen peroxide.But the reaction is very slow.What maybe the problem or if there any catalyst please help.
NOTE:after my search on internet I found that I should...
Homework Statement
A solution of AgNO_{3} is added to a solution containing 0.100 M Cl^{-} and 0.100 CrO_{4}^{2-}.
What will be the concentration of the less soluble compund when the more soluble one begins to precipitate?Homework Equations
Ksp AgCl = 1.82 x 10^{-10}
Ksp Ag2CrO4 = 1.2 x...
I can't bring myself to like this subject. And I can't do my desired course without being good at it. Its like one information after the other and some things make no sense and too many exceptions. :cry:
If there's someone out there who likes chemistry, then please tell me what about this...
Homework Statement
Homework Equations
The Attempt at a Solution
Shouldnt the name for that be 3-fluoro-2-methyl cyclopentene instead of 4-fluoro-3-methyl cyclopentene ?, if not can someone explain to me why ?