Homework Help

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Is this the correct explanation and Lewis structure for ch2O?

Hi guys, this is my first post here, I hope to have fun here. So, I need help with my grade 7 heat project, I need to make a thermos with a water bottle and other house hold items. The teacher will put hot water in each person's project, and after a certain period of time, will measure the temperature of the water, and the group with the warmest water wins. I'm thinking of wrapping the whole bottle with thick yarn first, put a layer of Styrofoam under the bottle, and cut a hole into two Styrofoam bowls and put packing peanuts/ newspaper balls in the bowls and taper the two bowls together and slide it over the bottle where the circle is. Then wrap the whole thing in f…

1. Just in general? 2. In chemical properties? Thanks in advance!

Point P(2,3) is on the graph of f, find the corresponding point on the graph of y=-3f(x+2)-4 I have it solved, but I don't understand how to solve it. What I have: P(2,3)---> (0,-13) y values multiplied by -3 and subtract 4 x values minus 2 Can somebody explain the process in details please.

Sulfuric acid (H2SO4) is a strong acid, which dissociates when dissolved in water according to the following equation: H2SO4 (aq) → 2H+ (aq) + SO42-(aq) A 0.21 g sample of sulfuric acid is dissolved completely in sufficient water to make 0.25 litre of final solution. Calculate the hydrogen ion concentration (in mol l−1) in this solution. Give your answer in scientific notation to an appropriate number of significant figures. Remember to show the successive steps in the calculation, and to explain your reasoning. What is the pH of the sulfuric acid solution (to the nearest whole number)?

My teacher is pretty strict about details, and I'm working on an assignment about writing/balancing chemical reactions. The question is: He never really mentioned how to write the heat part in the equation, so I kind of just winged it. This is what I got: Ca2(CO3)2 + heat → 2CaO + 2CO2 Have I written that correctly? (Sorry, the subscript letters didn't carry over properly from MS Word.) EDIT: Also, how would you write decomposition? For example: How would I write "decomposes"?

Ok so I've been working on this problem for what seems like forever now and I can't get it. Can someone PLEASE help me?! It has a picture of a flask that has a bulb on each end, these two bulbs are connected. Question: Consider the flasks in the following diagram. What are the final partial pressures of H2 and N2 after the stopcock between the two flasks is opened? (Assume the final volume in 3.00L) What is the total pressure in torr? One side of the bulb is H2 and it has 2.0L H2 and 475 torr. The other side is N2 and has 1.0L N2 and .200 atm. Please someone help me!!!!! This is due tomorrow and I have no clue how to work this out, I've tried everything …

Hello, I really need help with my homework. I really have a hard time with science and I try really hard. Can someone check if my answers are right? I tried the best of my ability to answer these so please help me out. the star means the answer i think it is. 1. How many protons should be added to the nucler of oxygen atoms so the resulting gas will flow red when an electric current flows through it? A. 1 B. Protons have to be subtracted not added.* C. 4 D. 2 E. 3 2. One element is distinguished from another by number of A. Protons B. Neutrons C. Electrons D. All of the above.* 3. Which of these atoms has the greatest amount of electrical charg…

Is there a reason as to why an Alloy can have such a different melting point to its composing metals?

I'm trying to figure out how to do instantaneous rates, but it seems like I need to know calculus to do this. I don't know calculus, and it wasn't listed as a prerequisite; I wasn't told the first day I need to know anything beyond basic algebra. Anyway, I'm suppose to find the "slope of a line tangent to the curve at any point." I don't really understand that. I tried searching for hours about this stuff, and I couldn't really find anything to help me; well, I tried analyzing stuff, but I couldn't see how it applied to what I was doing. The book didn't have that information. I know how to find the slope of something. But drawing this line against the curv…

What is the longest cell in the human body?

Greetings, I was wondering if someone could help me with some of my chemistry difficulty. I have to do an experiment to find the solubility of calcium hydroxide. I have gone as far as to prepare the saturated solution of calcium hydroxide and to plan a titration with HCl. My problem is that I do not know what concentration of HCl I should use, how would I calculate a reasonable amount? Also, correct me if this is wrong. If I measure out 0.5g of calcium hydroxide dissolve it in water, filter it through a funnel and then titrate the saturated solution, I will be able to compare it with the original mass I measure out. To compare the solubility would I just say the mass …

So for my mechanics class we have these two problems on our online homework: "An object in the shape of a thin ring has radius A and mass M . A uniform sphere with mass m and very small radius is placed with its center at a distance x to the right of the center of the ring, along a line through the center of the ring, and perpendicular to its plane. What is the magnitude of the gravitational force that the ring-shaped object exerts on the sphere?" and "A thin, uniform rod has length L and mass M. Calculate the magnitude of the gravitational force the rod exerts on a particle with mass m that is at a point x along the axis of the rod a distance from the c…

I am doing a project in science, and I need a device that is able to kill a static charge. I used to have it so the charge would run outside and run into the ground through a copper rod, but my science teacher said that I need to find a way so that I don't need to run it outside. The reason I can't find it myself is that whenever I search up "Device that kills static charges" on bing or google, all I get is websites saying if you can get killed by static discharge or not. Thanks!

I've been given this redox equation to balance: CH3CH2OH + Cr2O7(2-) --> CH3COOH + Cr(3+) The 2 half-reactions are: oxidation of ethanol: CH3CH2OH --> CH3COOH reduction of acidic dichromate ion: Cr2O7(3-) --> Cr(3+) What I got was: Ox: CH3CH2OH + H2O --> CH3COOH + 4H+ + 4e Re: 14H+ + 9e + Cr2O7(2-) --> 2Cr(3+) + 7H2O I then added multipled the top equation by 9, the bottom by 4 and then added the 2 equations together to get: 9CH3CH2OH + 4Cr2O7(2-) + 20H+ --> 9CH3COOH + 8Cr(3+) + 19H2O Does any1 agree with my answer? (I just think the numbers seem a bit big...)

Hi, I'm new to this site but I need a great help on my bio. Question: How many ATP molecules are formed in process of glycolysis itself? How many ATP molecules are formed in the process of respriation? How many ATP molecules are formed in process of glycolysis and fermentation (meaning the combination of those two)? I know for total thing, glycolysis and respiration whole thing will make 36 ATP molecules. But there occur confusion to me on the book. It seems the diagram is saying like 4 ATP are formed on glycolysis but in the paragraphs, it's only 2 ATP on glycolysis. Same thing for respiration. Diagram looks like 32 ATP but 34 ATP on paragraphs. For fermentation …

Hi I am trying to help my 11 year old son, who has aspergers syndrome, with his science homework. He has got to give an example of a reaction which will give off oxygen, a summary of how to test for this & draw & label a diagram of equipment needed. He has done it for hydrogen & carbon dyoxide but is struggling to find info on oxygen. (so am I as I have to type it all up for him & find the pictures to go with it)! Can anyone help! Many thanks

I would like to have some help figuring out how many people that is needed in order to lift a car (and how you would calculate it). Here is an example of the problem: Mass: 500 kg Length of the bottom of the car: 2,5 m Width of the bottom of the car: 1 m Height of the car: 1,5 m Let's assume the car is shaped as a regular box. Let's assume that the mass is distributed evenly throughout the box. All the people to lift are placed around the car with equal distance between each other (if you drew a polygon connecting everyone, all the sides of the polygon would have the same length). Everyone is holding underneath the bottom of the car. Let's assume…

OK, a titration question for you here: "In order to determine the aspirin content of a commercial aspirin tablet, a tablet weighing 0.400g was dissolved in aqueous ethanol and titrated with 0.100M NaOH solution: 16.7cm^3 of the NaOH was required to reach the end point. Under the conditions of the titration, only the Carboxylic acid group reacts with the NaOH". Obviously, the question goes on to ask about moles in the aspirin, and the % by mass of aspirin in the tablet, but what I need to know is what is the balanced equation for this reaction? NaOH + COOH -> ? Cheers, Thanks for your help.

Hi, I have a question about normal distribution. A large population of animals were found to possess a mean length of 18cm with a standard deviation of 2cm. What percentage of animals are longer than 20cm? so i know you use the formula to standardize the Z. But then from the cumulative table, how do we know which column to look for? and then the next question is, What percentage of animals should be between 15cm and 20.5 cm in length? in the formula, how do you put both figures 15 and 20.5 ? and then the last question is What length should enclose the shortest 60% of the animals ? please help Also does anyone know a good website for statistics ?

Hey can some1 help me with writing net ionic equations? For a reaction between sulphuric acid and copper(II) carbonate, I think the equation is: H2SO4 + CuCO3 --> H2CO3 + CuSO4 but then how do I know which one ( H2CO3 or CuSO4) breaks into ions and cancels out with the reactans to get the net ionic equation?

and how do you figure out their structural shape? I don't understand how you can just tell either of these two things and looking at this list of molecules I have to answer these questions too is might discouraging. Anyone with any pointers?

In my GEN BIO 1 course we just did cell division. I breezed through the chapter since it was a nice review from AP Biology. All of the sudden, when I got to lecture, though, I was slammed with confusion. On my professors powerpoint, for mitosis she had labeled Interphase as going from 2n--->4n. This made no sense to me. Isn't the DNA replicated in S phase, and the number of chromosomes remains the same? So for instance, if this was a human cell and there were 46 chromosomes, wouldn't this indicate that there are now 92 chromosomes (4n)? 92 chromatids, yes, but chromosomes? Seems weird. For prophase all the way to telophase she has "4n" underneath each phase picture…

I've been given this question as a part of a revision tutorial. I've already done the calculations but was wondering if anyone could point out any glaring errors. This is not an assessed piece of work, so strictly not homework per se. The turnover number of carbonic anhydrase: Carbonic anhydrase of erythrocytes (Mr 30,000) has one of the highest turnover numbers among known enzymes, it catalyses the reversible reaction of CO2: H2O + CO2 -> H2CO3 This is an important process in the transport of CO2 from the tissues to the lungs. If 10μg of pure carbonic anhydrase catalyses the hydration of 0.30g of CO2 in 1min at 37°C at Vmax, and the reaction volume is 1m…