Homework Help

I'm doing a lab report for an experiment about gas laws for my college chemistry class. One question is, "Use P total = P atm = P gas + P water to calculate the partial pressure of the butane gas collected." How would I figure out this problem? I also have P atm = 0.9733 atm, volume of gas is 94.2 mL, temperature is 21 degrees C from my data if this helps. Thank you!

i keep getting stuck in some problems of physics because the differential equation of the form a dy/dx + by = c f(x) keeps cropping up. is there any general method to solve this differential equation? when f(x) is sinusoidal, we avoid it using j operators and get the solution but in my particular problem f(x) is exponential.

Hello everyone. I have an urgent electricity question which can be viewed in the attachment. The question is: Calculate a)the current in the main circuit b)the p.d. across the 4 ohms resistor c)the current through the 12 ohms resistor For part a), What I did to find the total resistance is to find the resistance of the resistors connected in parallel first. So 1/R = 1/4 + 1/12 gives 3 ohms. Then I would add 3 ohms with 7 ohms, which would be equal to 10 ohms - that is the total resistance of the circuit. Now I have to apply Ohm's law - I = V/RI = 20V/10R =2A Can anyone please help me in part b and c? Thank you so much!

I am just a bit confused about whether we should use a truncated value in calculation, personally I think the answer should be 'no' (as multiple rounding-off or truncation adds uncertainty), but I just want a confirm. Say for example, I worked on raw data and got an eqation of: y = 0.784x(plus or minus 0.002)+0.059(plus or minus 0.008), so here 0.784 and 0.059 are truncated values based on the standard deviation (0.002 and 0.008). Now if y is 0.224, shall I use the raw values (that is, the original values not truncated) or truncated values of 0.784 and 0.059? If if use the truncated ones, then, 0.224 = 0.784x+0.059, x=0.210(3 sig fig). I just feel a little bit weird no…

Hey guys, I got a homework assignment I'm having a lot of trouble with. This is post #1, I'll post a few more regarding the other problems in the homework. I'm not looking for an answer, I'm looking for assistance in how to proceed. This is new to me and very confusing, and my confidence in QM is very low after last semester's course (we all failed, if you remember... had a makeup test that also didn't go well, but I ended up getting a C+, which I usually consider as failure, but in this case, at least it's *passing*... err) Anyways, problem 1: If A,B are two linear operators on a Hilbert space, show that a^(A) B e^(-A) = B + [A,B] + 1/(2!) [A,[A,B]] + ..…

Last question for this series. I started answering this one and got stuck. Again, this subject is new to me, so forgive me if I miss obvious stuff.. I'm getting used to the format and the method. I don't want to copy an answer, of course. I would appreciate an explanation and/or a way to continue so I can go on to other similar problems and also understand how to solve these type of questions in the future. Thanks! Problem 3: The Hamiltonian for three-dimensional system is of the form: [math]H=\frac{p_{i}p_{i}}{2m}+V[/math] where V depends only on r. Obtain the commutator [math] [x_{k}p_{k},H][/math] -- Here's what I have so far: [math] […

If we have 3-Heptanone and 2-Heptanone, what value would we get for 3-Heptanone? Also is the C=O group in the 2-Heptanone structure is replaced by the C=S group or the C=Se group. What dipol moment values would you expect for the resulting structure. I'm not sure how to answer this

Can someone please tell me why do aircrafts have pressurized cabins? Has it got something to do with the difference between the low atmospheric pressure outside the aircrafts (since they fly at very high altitudes) & the pressure inside the aircraft? Also if the same force is applied for the same time to a car & a loaded truck, which of the two will pick up greater speed & why? Thanks, Ron

So I'm stuck. I don't know what to do if I don't have the formula for the copper chloride... The table of information just makes it more confusing, because I don't know if i should average the values out or what...it all seems so ambiguous to me. Help please.

Im unsure what im supposed to do. Please dont just be blunt im actually lost here.. I need direction. 25. The following reaction represents the decompostion of water: 2 H2O ---> 2H2 + O2 How many molecules of hydrogen are produced from the decompostion of 12.2 g of water into its elements? (4 marks) 26. Determine the mass of carbon monoxide that is produced when 45.6 g of methane, CH4, react with 73.2g of oxygen gas, O2. The products are carbon monoxide, CO, and water vapour H2O. (7 marks)

sorry I put it on the wrong forum before if you have any two gases in different containers that are same size at the same pressure and temperature, what is true about the moles of each gas i got it how do I delete a topic anyway?

Alright so I did have all of the equations written quite nicely before but I clicked back and all that time spent typing the equation with the correct subscripts and all, but I realize I don't not really need all the information to understand this step. Basically I am doing a titration lab but I am having problem with dilution: It seems they want me to dilute it twice before titration, Solution X than use Solution X for Solution Y. Solution Y is what will be used for titration. Borax: 3.115x10-3 mol Dilute into a 100ml (0.1L) flask which will become known as Solution X: 3.115x10-2 M Borax Now this following part is where the confusion lyes, I don't know if it…

I just started intoductory astronomy and I have difficulty understanding this problem. Any help would be appreciated For a place at a latitude of 55 degrees, determine how high above the horizon the sun is at noon on 1) The Vernal Equinox 2) The summer solstice 3) Winter solstice

Determine the number of moles of N atoms in a sample of C_7 H_5 (NO_2)_3 that has the same number of O atoms as 13.4 g C_6H_12 O_6. My first attempt 13.4 g C_6H_12 O_6(1mol C_6H_12 O_6/180.15768g C_6H_12 O_6)(6 mol O/1 mol C)=0.4462757291 mol O... since the values are equal I figured that the N would be the same; wrong! (I know the masses of C_6H_12 O_6 are slightly different) After some time I came up with 13.4 g C_6H_12 O_6(1 mol C_6H_12 O_6/180.1566g)(6 mol O/ C_6H_12 O_6)(6.022*10^23 atm/1 mol O)(3 mol N/6.022*10^23 atm)=1.33|8839672~1.34mol N... That however did not give the right results... Relating the number of atoms seemed strange to me but it seemed…

Okay it gives the structure for alanine: ------CH3 H2N -- C -- COOH -------H Then it says: Give the systematic name for alanine. I don't know how to name amino acids, so can someone tell me how to? Thanks.

A conical pendulum consists of a bob of mass 0.3kg attached to a firm string of length 0.67m. The bob rotates in a circle of radius 0.36m, vertically below the point of suspension. Calculate: i) the linear speed of the bob ii) the period of rotation of the bob iii) the tension in the string Please help!!!

If the sidereal period of the moon was 29.0 days(I know usually its 27.32 days), what would be its synodic period? In doing this problem I have considered how far around the sun the Earth/Moon will have travelled in 29.0 days but then I am stuck Any Help would be appreciated

Hello my fellow scientists, I'm a chemistry freshamn student and my Physics Prof. told us that we had to cover the part of all classic physics with an essay... presonally I don't think that's a good idea, I dislike essays, I'd prefer to solve a bunch of problems rather than doing this, but ehhh. So yea, from the several things I have to research I have problems explaining what do classic physics study (explaining kinetics, dynamics and statics) I can´t find that in any book, they all start with newtons amazing laws . Ohhh and can anyone tell me what are fluid dynamics, molecular dynamics in proteins and energy analysis in physical-chemical systems?? I'd be really grateful…

I am not sure if I call the topic 'linear regression' is right, actually it is about 'least square analysis' in constructing a best-fit line, but when I googles the phase 'linear regression' some relevant information pops out. So assuming now we have a set of data, y values correspond to x values; plotting it in y vs. x manner it appears to form a straight line, but now we want the best-fit line. The method is to select an m value and a c value, by y = mx + c, to minimize di = sum[(actual y)-(computed y)]^2, I can do this step. What I got difficulty is to find the standard deviation of m and c. Sy^2 = di/(n-2); In a lecture I heard about: Sm^2 = (Sy^2)(n/D) …

Hi all, In one of my biochemistry courses, we went over the cdc (cell division cycle) mutant screen using conditional mutants (temperature sensitive). Yeast cells were exposed to ultraviolet light (to cause DNA mutations). Next, they were plated and incubated at 25 degrees, then replica plated and incubated at 37 degrees. The temperature sensitive clones were isolated and examined for cdc mutants. I am a little confused about the conditional mutants in general so my questions are... 1. What is the purpose of incorporating conditional mutants in an experiment? (I guess my question really is, how do they know the temperature sensitive clones contain cdc mutants…

Hi! I have a question about probablility. I don't know what the name of this type of statistics is, but here goes: John has three exams coming up, one in Math, one in Physics and one in Biology. He thinks his chances of passing are 0.8 for Math, 0.7 for Physics and 0.3 for Biology. His result on each exam is independent of the others. a) What is the probablility that he passes at least two of the exams? b ) Given that he has passed two of the exams, what is the probability that he has passed the exam in Math. I would love some help with this, either in the form of a direction to online pages that has examples of this kind of problems with solutions, or if y…

I received a text message from a friend who is a teacher in grade school and was not sure how to answer it other than to say I really can't do anything about it. Anyway, I thought I'd post it here and then link the thread to the person who sent me text message. Here it is. Any input would be appreciated. How do you interpret the theme "Kids of the new decades moving beyond science clubbing continuum"? Please provide example. What is a good slogan for this theme?

We are to find the annual growth rate of a fish from 2003-2007. The measurements are taken in March and September of the same year. This is throwing me off in determining the growth rate. In general if it just said the year and then the measurement (without the two different months), I'd subtract the first year measurement from the final year measurement and divide by 4. However, when two months are involved, this doesn't seem to work. This also leads me to believe that you need to account for 5 years instead of 4. Any advice on how to go about it? March 03 : 2cm Sept. 03: 4.5cm March 04: 4.7 Sept. 04: 6.6 March 05: 7.0 Sept 05: 9.2 March 06: 9.3 Sept…

Hi i need to know how I would plot this graph on a log-linear graph paper? (data is below) and how do i found out the gradient ? (Y=mx + c) :S Time (h) 0 24 48 72 96 120 144 168 192 Cell conc (cell/mL) 8.0 X 104 1.0 X 105 1.3 X 105 2.6 X 105 4.5 X 105 9.6 X 105 1.89 X 106 3.10 X 106 3.84 X 106 Thanks in advance

When I checked my edline and discovered that I had a 'D' in Trigonometry, I wasn't too flustered by the fact that I was doing poorly, but I was flustered most by the fact that I had no idea why I was pressing 'sin', or 'cos', or 'tan'... I know what they mean. I know their reciprocals. But, I don't know when to use them, and always have to look at previous problems, looking for patterns. I probably could memorize the patterns, but would that really be learning trigonometry? I still wouldn't know why I was pressing the function buttons. So, I decided to delve deep into the roots of the subject because History is a subject that I get A's in. I learned about Hipparchus, and …