Homework Help

When Calcium react with Copper(II) Nitrate, the balanced equation is simply: Ca(s) + Cu(NO3)2 (aq) --> Ca(NO3)2(aq) + Cu(s) [no gas produced] Why is it that hydrogen gas is also produced in the same reaction: Ca(s) + 2H2O(l) --> Ca(OH)2(aq) + H2(g) What would then be the complete balanced equation for the reaction between Calcium and Copper(II) Nitrate when there are 2 different reactions occuring in one chemical reaction? Hence how do I determine when the water in an aqueous solution will or will not have a reaction to produce a gas in all other chemical reactions? Do aqueous solutions have any specific reactions in chemical reactions?

I hope this sort of question is allowed on this forum. Im in high school and I'm going to be writing an science paper soon, "APA" style. As I topic Iv decided to test for vitamin C in various juices. I plan on seeing how the amounts change over time, both refrigerated and unrefrigerated. Questions: 1. Are there other chemicals that could easily be tested for in juices? I need plenty of data to write 2,000 words. 2. Whats the best method for testing vitamin C in juices? I need something that will be able to test for small changes. There seems to be two methods Iv found: chemical test strips, and titration using iodine and startch. Strips: http://www.naturamar…

Hi there. Got a problem. I have the equation P equals rho x omega x upsilon x s Problem is that I do not know what each of the symbols correspond to and what units I need to put them in as. Can anyone help or point me in the right direction. I have been looking for the answer for this one for ages. Its possibly shown in a different way elsewhere? Many Thanks Rich

Hi, wonder if anyon could help? I am looking to find the displacement amplitude of a speaker. I have the diameter of the speaker, the frequency, air pressure and density and asumed speed of sound. Anyone point me in the right direction for an equation to fit this? THanks Richard

Guys I'm doing an introduction to statistics course and I'm sort of stumped. I can manage the calculation aspect as its more straight forward but when u have to prove stuff, I'm hopeless. Any help with this please, Prove that if event A and event B are not mutually exclusive, then P(A or B) = P(AUB) = P(A) + P(B) - P(AnB) Would appreciate any help. Thanks.

The covalent radius of an aluminum atom is 1.18 x 10^-8 cm. Assuming that in aluminum foil,the atoms are packed one on top of each other, how many atoms thick is a sheet of aluminum foil? (if aluminum thickness= 0.0017) for this.. ive tried dividing the thickness with the radius/diameter, giving me answer of around 14k and 7k but not sure if that is correct or what is the right way to solve it. then i have no idea what to do for this problem, A cube of aluminum of side 2.00cm has a mass of 21.60g. Using the covalent radius of an aluminum atom, calculate the volume of the "empty space" inside the cube.

how many times can we differentiate this splitted function on point x=0 ?? [math] f(x) = \{ x^{2n} \sin (\frac{1}{x}) ,x \ne 0 [/math] on {0,x=0}

Hi. I just started year 10 and we already have an assignment. This year I need to do well in Science to get into physics, so I figured I should get all the help i can for my assignments. We have to write a 300+ word essay ("response") to this statement: "Hydrogen and bio-fuels are the only transport fuels that even putatively tackle both global worming and oil depletion, and they appear to be completely inadequate to the task" The Main question is: Do you think that hydrogen and biofuels are the only fuels available to ward off the consequences of running out of oil and climate change? Your discussion should include an analysis of the hydrogen and biofuels indus…

may i know the full answer for this....it was posted earlier by candiishop bt i cant see the full answer...here is the question : Predict what would happen to erythrocytes placed in a solution containing 300mOsm/L urea and 300mOsm/L sucrose (i.e. a total of 600mOsm/L of particles in one solution; and remember that this is NOT made by mixing equal volumes of 300mOsm/L urea and 300mOsm/L sucrose). Fully explain your answer.

Ok I don't know if I'm gonna sound dumb, but I am doing my 6th grade science experiement and i need to know what the control is. I am going to test tap, bottled, fountain, and toilet water. I want to see which one has more bacteria and which is more drinkable, i read somewhere that toilet water is just about the same as fountain i want to know. Can somoen tell me what the control is because i cant figure it out

This is a question I have worked on in Stats and my answer does not line up with the solution manuals. [math] P(A' \cap B' \cap C) = P© - P(A \cap C) - P(B \cap C) + P(A \cap B \cap C) [/math] My answer there is a negative before [math] P(A \cap B \cap C) [/math]

Hey, just wondered if you guys could clear something up for me:D When using the beer lambert law, should you use the Absorbance value at Lambda max, ie the highest absorbance? (because presumably using different values would lead to different molar absorption coefficients, which isn't good)

Suppose two quantities, A and B, have diff dimentions. Determine which of the following arithmetic operations could be physically meaningful (select all that apply). 1. AB 2. A/B 3. B-B 4. A-B 5. A+B I have tried choices 123 and 13, yet both were wrong. I know that 4 and 5 are wrong because you are subtracting different units. I thought that 2 was wrong because what if B=0, then it would be undefined. For 3, you are subtracting within the same unit, so it has to be correct. I am not sure at this point. Any advice is welcome.

i am given two differentiable function f and g . prove that for u(x)=max(f(x),g(x)) and v(x)=min(f(x),g(x)) there is one sided derivatives ??

First off, I am sorry for being blunt with my questions but I am honestly stumped. Can anyone lend a thought? The first question I have no idea how to even get started. Estimate the copy number of pET22b+ in the average E.coli cell. You may assume that there are approximately 1 X 109 E.coli cells in each mL of overnight-saturated culture. The size of the pET22b+ plasmid is ~5500 bases, the size of the insert is ~500-800 bases, and the average molecular weight of a nucleotide base pair is 660 g/mol. Or this question: How could you use this sequence to design a 5’ primer that could sequence your own DNA to determine if you have any genetic polymorphisms in yo…

Compound B is acetylcholine, a neurotransmitter found in the human body. It binds to receptors, leading to nerve stimulation. COMPOUND B CH3 O | || H3C- N+- CH2- CH2- O-C- CH3 | CH3 (in case the thread does not show correctly, the CH3 with the single line underneath places above the N+, the O with the two || below it places above the C and the CH3 with the line above it places below the N+) (i) Name two types of interaction, other than van der Waals or hydrophobic interactions, by which compound B could bind to the receptors. (ii) Identify two different types of g…

I need to work out a perctange yield for my experiment, however i am having trouble balancing the equation. H2SO4 + C6H5Br + HNO3 --------------> C6H4BrNO2 + H2O this is what i have so far.. but there is no S on the right side of the equation.... im very confused.

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I am trying to prove the follow two questions without using the differentiation formulas for inverse trig. or inverse hyperbolic functions. [math] \arcsin(u) = \arctan(\frac{u}{\sqrt{1 - u^2}}) [/math] I have been looking at it as [math] \frac{opp}{adj} = \frac{opp}{hyp} [/math] but something in my steps is off. I am also trying to solve [math] \frac{d}{dx}[\tan(\arcsin(x))] = \frac{1}{(1 - x^2)^\frac{3}{2}} [/math]

How do you make 200ml of a 0.1M solution of a substance that has a molecular weight of 121.1g/mol?

here is the question and how i tried to solve it??

Find the lattice enthalpy of MgF2(s) Mg(s) + F2(g) -------- MgF2(s) -1102 kJmol-1 1/2F2(g) -------- F (g) + 79 kJmol-1 F(g) + e- -------- F-(g) -348 kJmol-1 Mg (s) -------- Mg(g) +150 kJmol-1 Mg (s) -------- Mg^2+ (g) + 2e- +2186 kJmol-1 My calculation is : -1102 + 79*2 + 348 *2 - 150 -2186 and my answer is :- 2584 but the modal answer is -2821 can anyone please help me thankx

Hi, hopefully someone can help me with this question: 1. Write an equation to show the reaction between ethanol, C2H5OH and methyllithium, CH3Li. In this reaction, ethanol is a Lewis acid and CH3Li is a Lewis base. Draw all non-bonding electrons and show electron flow with curved arrows. I basically can't figure out the equation: should it produce CH4 and C2H5OLi or LiOH and C5H8? Also then, I need help with the electron flow. Thanks in advance, K.