Hello, I had my AP Chemistry midterm recently, and there was one question that seemed actually impossible. It probably isn't, and I wanted to see if any of you could solve it. (It seemed like it was impossible to combine the two last equations into the first.) This is the question.
Use Hess' Law to calculate the enthalpy of this reaction in kJ/mol:
4PCl3 => P4 + 6Cl2
Use these two equations and their respective enthalpies:
4PCl5 => P4 + 10Cl2 (1528 kJ/mol)
PCl3 + Cl2 => PCl5 (-111 kJ/mol)
Hello everyone i search a man or a woman who has resolve the Riemann hypothesis because that very important !
Please help me solve this question. An abrupt slowdown in concentrated traffic can travel as a pulse,termed a shock wave, along the line of cars, either downstream (in the traffic direction) or upstream, or it can be stationary. Figure 2-25 shows a uniformly spaced line of cars moving at speed v " 25.0 m/s toward a uniformly spaced line of slow cars moving at speed vs " 5.00 m/s. Assume that each faster car adds length L " 12.0 m (car length plus buffer zone) to the line of slow cars when it joins the line,and assume it slows abruptly at the last instant.(a) For what separation distance d between the faster cars does the shock wave remain stationary? If the separation is twice that amount, what are the (b) speed and (c) direction (upstream or downstream) of the shock wave?
Here I'm ready for all questions
I like physics and Biology
If you have any questions ask to me
I'm a teacher of a school
| 20558 - Reply from riemann64 , 100 yrs (germany) - 2019-11-24 |
|hello could you help me how to resolve a bilan of energy with the equation of conservation ?|
| 20473 - Reply from Simeon205 , 13 yrs (Nigeria) - 2019-08-03 |
|My name is simeon please can you help me solve this question. Compute your average velocity in the following two cases: (a) You walk 73.2 m at a speed of 1.22 m/s and then run 73.2 m at a speed of 3.05 m/s along a straight track.(b) You walk for 1.00 min at a speed of 1.22 m/s and then run for 1.00 min at 3.05 m/s along a straight track.|
| 20433 - Reply from Julia64 , 13 yrs (Poland) - 2019-05-29 |
|Hi Charles Reiss, how can I help you? I learn this one mounth ago, so I'll be happy learn you.|
| 20424 - Reply from Charles Reiss252 (England) - 2019-05-21 |
|Hi there, can you please explain to which forms of energy can exist in|
If anybody else loves since feel free to answer
Hey folks is there anyone else who loves physics too? Feel free to answer:)
Hey there, I am rishabh and I am finding buddies to study chemistry. I know English because all my textbooks are in English. Thanks in advance.
Hey everyone. i'm doing Chemistry in High school.Anyone interested in Chemistru feel free to talk to mr.
| 20328 - Reply from Marek34 , 14 yrs (Netherlands) - 2018-12-03 |
|Hey I'm also in high school and I love chemistry so when do you want to talk about it?|
I'm currently studying Maths, Further Maths, Chemistry and Physics at A-Level! Anyone studying similar subjects or just has a genuine interest in STEM, don't be afraid to drop a message! :)
| 20479 - Reply from Sandali135 , 17 yrs (Sri Lanka) - 2019-08-09 |
|I'm also studying Physics and Chemistry and Biology. Actually they are very enthusiastic subjects.|
| 20360 - Reply from Sam181 (Germany) - 2019-01-30 |
|Hey, I am interested. :)|
| 20358 - Reply from Anna57 , 20 yrs (China) - 2019-01-24 |
|Yes,I am a collage student to learn chemistry!!
But I cannot said it in English haaaaa
| 20353 - Reply from Emina41 , 15 yrs (Zimbabwe) - 2019-01-17 |
i'm interested in those subjects too
I am just looking for people who love science and technology
| 20421 - Reply from Nattcha12 , 22 yrs (Thailand) - 2019-05-10 |
|Hello .. I'm interested in science too you can send me an email. If you want ...thanks|
SIENSE ISS FUNN ANND MAKS TINGS EXPLOD.
Anyone interested in physics education? I'm going to Washington DC this summer for a conference about physics education research. (kind of nervous.....)
Does anyone want to be study buddies? I am doing a level CHEMISTRY and BIOLOGY and we could help eachother :)
| 20292 - Reply from Sun155 (China) - 2018-09-22 |
|Hello!You can call me Delis.I am an senior high school student in China.In fact I know a lot about Chemistry and Biology.I am glad to become your friend!|
| 20277 - Reply from Eric230 , 18 yrs (Spain) - 2018-08-27 |
|Hey! I'm studying a Biochemistry university degree in Spain! We could talk if you want to!|
| 20263 - Reply from Marvin215 , 13 yrs (GHANA) - 2018-07-09 |
|Marvin is my name.I'm 13 years old.I have hobbies. Such hobbies like;reading,painting and drawing,watching television etc.|
| 20255 - Reply from Kelvin173 , 28 yrs (Poland) - 2018-07-07 |
Kelvin here from Poland. We can be study buddies for sure. Kindly email me for more details and it will be worth it. I am an Informatics student in Poland. My email address email@example.com
Hello, I am studying physics and would love to find people who are studying the same subject or are at least interested in physics. I will wait for your messages ;)
| 20552 - Reply from aldo 187 , 21 yrs (mexico ) - 2019-11-12 |
|Hello, I study aeronautical engineering where physics is the most important thing I would like to talk to you about how physics looks in your countries and how they analyze it
greetings, I wait for your message
| 20361 - Reply from Samantha181 (Germany) - 2019-01-30 |
|Hey, I want to study physics later on in my life but I always searched for someone to talk to about it.
We could learn together?
| 20273 - Reply from ALI178 , 31 yrs (maroc) - 2018-08-23 |
|I have a degree in physics and now I am preparing a new degree in Applied Math|
| 20238 - Reply from Martin178 , 19 yrs (Burkina faso) - 2018-06-16 |
|I like physics and chemistry too.Tereby i study in physics field and i will love to be in touch with other physics fans|
| 20205 - Reply from Minfan83 , 31 yrs (Taiwan) - 2018-04-17 |
|I love physics and the philosophy in it. (Relativity and Quantum Physics are amazing~)|
| 20180 - Reply from Omar46 , 17 yrs (iran) - 2018-02-15 |
|I am much intrested in Big Bang theory of the universe.
And yeah my field is math and physics with includes science in it to.
I'll be waiting to learn something from you or from someone else.
| 20179 - Reply from Maelis233 , 16 yrs (France) - 2018-02-12 |
| Hello ! :) I like physic too more precisely astronomy and the infinitesimal. What fields are you studying ?|
Comment maîtriser ce thème facilement ??
| 20258 - Reply from Magali94 (France) - 2018-07-07 |
|Salut pour maitriser le sujet qu'est l'éthanol. Il faut savoir pour commencer sa formule :CH3-CH2-OH. ensuite il faut savoir que c'est un liquide incolore, inflammable et miscible comme avec de l'eau par exemple. L’éthanol est un solvant tu peux le retrouver dans les produits cosmétiques. C'est un isomère de l'éther. L'éthanol peut-être créé industriellement ou naturellement (ex : la levure...)
J’espère avoir pu t'aider. ;)
calculer le nombres de protoons et dedui en le nombre d electrons et de neutronsd ammoniac et merci beaucoup
Hi everybody,I love to study scienice and math.almost everytime I study about them. And do not worry about english, I have book about science and math in english, so don't worry , I can talk or explain something about science and math in english fluently,if you want study with me it's okay or we can talk somethinge about it.
| 20362 - Reply from Samantha181 (Germany) - 2019-01-30 |
|Hey, I am interested in math and physics, maybe we could learn together or just talk about it?|
| 20108 - Reply from huanhuan97 , 18 yrs (Chian) - 2017-11-05 |
| Hello, You are good at physics, and I want to learn physics with you in English. It is better for us to communicate with spoken english!|
| 20074 - Reply from Sarah233 , 12 yrs (Australia) - 2017-09-26 |
|What year are you in?|
I'm just looking for people who are interested in sceince and techology :D (it'd be perfect if you're interested in robotics, too)
| 20078 - Reply from Allou Michel145 , 16 yrs (cote d ivoire) - 2017-10-04 |
|slt les amis j'aimerai qu'on devient des portes|
| 20067 - Reply from Prisca158 , 13 yrs (France) - 2017-09-15 |
| Bonjour je m'intéresse beaucoup aux sciences.
Cela me passionne depuis longtemps.
Si tu veux en discuter contacte moi en priver
PS: sait tu parler français, si oui répond moi en français.
| 20041 - Reply from Vincent0 , 15 yrs (Kenya) - 2017-08-19 |
|I've a problem with Albert Einstein's relativity theory|
| 20014 - Reply from Ishwarya151 , 18 yrs (India) - 2017-08-02 |
|Hey Irina. I have been wanting to find someone who shares my interest in robotics and artificial intelligence for forever now. So I feel like I can sleep more in peace at night after having 'kind of' met you(over dramatic, I know).
Hence here is to hoping we can build our friendship on our love for science and technology(robotics especially). Looking forward to talking to you!!
I really need help in balancing chemical equations. Also writing ionic equations in preparation ofsalts. I
| 20114 - Reply from robin54 , 40 yrs (USA) - 2017-11-15 |
|Please post your equation. Let's check if I can solve it.|
| 19985 - Reply from jackson26 , 17 yrs (tanzania) - 2017-06-25 |
|bring your equation,(.......) eg.NaOH+HCl-NaCl+H2O|
You want to know some simple things in Electromagnetism, you are welcome to ask me doubt, In theory and simple problems. I dont deal with relativity and I am an electronics engineer doing PhD. My area is ultrasonics.
I am 13 but really interested in chemistry and physics. Our chemistry classes are a bit slow for me so I tend to read ahead but when I came across the s,p,d and f orbitals I was a little puzzled. Right now we are learning about the periodic table and I was curious, when are the d orbitals filled? I read that in some cases the electron valence changes and was wondering under which circumstances the third shell can allow 18 electrons? I will be very grateful for any kind of help :)
| 19904 - Reply from Maria211 , 25 yrs (Venezuela) - 2017-03-29 |
|Now, when can a metallic atom host 18 electrons? When it forms "coordinated" bonds with "ligands". These bonds are a different type of bond. They aren't covalent or ionic. It's a way of sharing electrons through the "d" orbitals of the metals, that is, the metal "accept" the electrons of the ligand, forming "complexes". These complexes can have certain geometrical structures, that depend of the metal and the ligands nature. So, sometimes, they form complexes in with the metal has a total of 18 electros (counting it's s and p electrons).
| 19903 - Reply from Maria211 , 25 yrs (Venezuela) - 2017-03-29 |
|Hello :) I hope I'm able to help you. The periodic table has different sections: metals, metalois and no-metals. The metals (the one we're interested in) are separated in three groups, one of those groups is called transition metals. Those metals are the ones that can extend their shell to accept up to 18 electrons. Why it happens? If you're interested I can tell you about it in another post. So, now, how can the metals extand their shell? Well, it is because the transition metals have "d" orbitals in which the extra electrons can be located. See this:
A metallic atom has s orbitals (2 electrons), p orbitals (6 electrons), d orbitals (10 electrons), in total, there are the 18 electrons ^_^
la construction,la chimie et la science j'adore ça parce que j'ai toujours aimer ça c'est trop bien les experience!
| 20079 - Reply from Aidan7 , 9 yrs (United States) - 2017-10-06 |
|hi mi name is aidan|
| 19978 - Reply from anthony29 (France) - 2017-06-14 |
|moi aussi j'adore l'electricitée les experciences TOUT|
Hi! Would someone be interested in debating about our world ? I mean, I'd like to argue about how do you imagine about our universe and all of that :)
| 19998 - Reply from Bugra209 , 13 yrs (TURKEY) - 2017-07-13 |
|Hi I think all the human history periot is just a second in cosmic time. So after a cosmic second there will be no life in the world as we know.|
| 19949 - Reply from axi54 , 16 yrs (Greece) - 2017-05-22 |
| 19946 - Reply from Denis246 , 17 yrs (Indonesia) - 2017-05-18 |
|I also want debating about that. If you want I will debate with you|
| 19847 - Reply from Camille216 (France) - 2017-02-20 |
I'm crazy about science of the universe and want to speak about this with other people.
You can send me a message !
hey, every one physics is my favourite subject. if you have any problem, you asked me.
I might be 11 but I know some things about science. Not just General or Agricultural. I mean Chemistry and Physics. Since everyone in my family took or is taking the Physics/Chemistry Course I picked up some lessons from them.
I can also help with English :P ^^
I have taken extra lessons in Language Arts, so I would think my vocabulary is of high standard. Not saying I'm the best though...
| 19779 - Reply from Sofia125 , 11 yrs (Trinidad and Tobago) - 2016-12-15 |
|Thanks ^^ I will.|
| 19778 - Reply from Altol51 , 17 yrs (S.Korea) - 2016-12-15 |
| Hi Sofia:) Wow!! All of your familiy members are now in Physics/Chem course?? That's nice!! I'm studying for university enrollment(Have you heard of KAIST? It's quite famous in Korea) and I wanna major in chemistry. If you have some questions to me, please feel free to ask!! I'll try my best to answer it:D|
Hi.I am sallqy. I am weak at physics.😭 Could someone help me.
I'm looking forward to your reply.
| 20293 - Reply from Sun155 (China) - 2018-09-22 |
|Nice to meet you!I am an senior high school student in China.May I can help you to improve your physics level(For example,I know a lot on Mechanics，Thermodynamics）|
| 20144 - Reply from Lola170 , 15 yrs (Argentina ) - 2017-12-17 |
|I’m studying chemistry and physics, if You need help with them, feel free to contact me!
I may be young but when I grow up I want to be a physicist.If their is anything I could do to help me prepare for that then feel free to tell me.
Hi!I am close to my exams and I hope somebody could help me with my physics,because I am very weak at it (TAT) It's okay if you are not very good, it helps a lot enen if you could teach me a little about it. Thanks!
| 19950 - Reply from axi54 , 16 yrs (Greece) - 2017-05-22 |
Je suis un étudiant en master chimie à la faculté des sciences à rabat (maroc )...
Hi! I'm going to university this year, I want some help in learning physics.
I'm really a lot weak in it..... but I want to major it 'cuz I like it....
I need a penpal whose good in it...
| 19988 - Reply from Gursafal90 , 18 yrs (India) - 2017-07-03 |
|I could help you|
For those in the UK, Im doing GCSE Chemistry, I have a deep interest in Chemistry and Physics. Can anyone Help me with Balancing Chemical Equations?
| 19696 - Reply from Alex9 , 14 yrs (Britain) - 2016-09-19 |
|Hello i just saw your post... i may only be 14 but i madly love doing chemistry equations and trying to balance them, im always just a email away if you would like me to help you, i do triple science so yea
| 19540 - Reply from Î¤13 (ÖÐ¹ú) - 2016-04-30 |
|l am a student in senior high school.l like Chemistry and Physics too.We can learn together|
Hello everyone,I am from China.My major is Inorganic Chemistry. Now, I 'm studying for a master's degree.So,I hope to become friends with you,and common learn each other.
| 19496 - Reply from Janaiya77 , 9 yrs (USA) - 2016-03-08 |
|I love science What is like there????. I like to visit China some time|| |