Tuesday

August 4, 2015

August 4, 2015

Total # Posts: 95

**Organic Chem**

Thank you for the feedback but after selecting this option it came up incorrect
*February 11, 2015*

**Organic Chem**

Im not really sure how to begin with this question.. 1. The synthesis of toluene by the aluminum chloride-catalyzed Friedel-Crafts alkylation of benzene is badly complicated by the formation of di-, tri-, and polymethylated benzenes. A simple solution to the synthesis of ...
*February 11, 2015*

**physics**

I was looking at coulombs law and I thought it was inversely proportional but my options are only 1/r or 1/r^2 and the question states directly proportional. I dont see how either answer could be correct. I could see how q1q2 is directly but not with the r's
*September 15, 2014*

**physics**

Need quick help with this question. Is electric force directly proportional to 1/r or 1/r^2?
*September 15, 2014*

**Calc**

Thanks!
*May 13, 2014*

**Calc**

Let f(x) = x^2 -2x a) Estimate f'(3) using h = 0.03 b) Find the exact value for f'(3) c) Give the equation of the tangent line to f(x) at x=3 d) Use the tangent line to estimate f(2.98) e) Critical points
*May 13, 2014*

**calculus please help!**

Nevermind on this question I figured it out
*May 13, 2014*

**calculus please help!**

Find maxima and minima and points of inflection. f(x) = 2x^3 - 3x^2 -36x +100 on the interval [-6,4]
*May 13, 2014*

**statistics **

3. The personnel director of a corporation will study the overtime work during the previous year for the 2,575 clerical workers. A sample of 100 of these workers will be chosen at random from the files. The average and the standard deviation of the overtime hours will be ...
*May 8, 2014*

**I need help with Physics**

A baseball of mass m1 = 0.46 kg is thrown at a concrete block m2 = 8.25 kg. The block has a coefficient of static friction of μs = 0.81 between it and the floor. The ball is in contact with the block for t = 0.165 s while it collides elastically. m1 = 0.46 kg m2 = 8.25 ...
*March 26, 2014*

**Physics**

Consider a car is heading down a 5.5° slope (one that makes an angle of 5.5° with the horizontal) under the following road conditions. You may assume that the weight of the car is evenly distributed on all four tires and that the coefficient of static friction is ...
*February 21, 2014*

**Physics**

A block with a mass of m = 21 kg rests on a frictionless surface and is subject to two forces acting on it. The first force is directed in the negative x-direction with a magnitude of F1 = 9.5 N. The second has a magnitude of F2 = 19.5 N and acts on the body at an angle θ...
*February 19, 2014*

**Geology**

If the decay constant for radioactive decay of ^40 K is λ = 5.543*10^(-10) / year, use this equation to calculate ages of the samples in the following table: t(1/2) = 0.693/λ 1)What is the half life of 40K? table -----Np --- Nd---- Nd/Np A)6439-----2303---0.358 B)...
*November 21, 2013*

**Spanish (need help quickly)**

I'm having trouble with indirect object pronouns in Spanish. Which indirect object pronoun would go in the blank? ¿Quién _____ ayuda a ti con los estudios? (This one I am thinking te) No_____ decimos mucho a nuestros padres. (For this one I was thinking nos) ...
*November 8, 2013*

**spanish**

Thank you so much!
*October 18, 2013*

**spanish**

I am so close to finishing my homework and these are the last few questions I have left. I keep trying but the program says whatever I write is incorrect. Can someone help me please? Rewrite the sentence with the direct object pronoun appropriate to replace the direct object. ...
*October 18, 2013*

**chemistry**

two tables containing electron impact mass spectra data are shown. select the molecule that corresponds to the appropriate spectrum A) m/z: 29 57 86 B) m/z: 43 71 86 options for both 3-methyl-2-butanone, 3-pentanone, acetone, benzene
*April 19, 2013*

**chemistry**

Predict the first order splitting patterns of the indicated proton in the following molecules: CH3CH2CH3 (the H in CH2 is selected) a) quintet b) quartet of quartets c)septet
*April 19, 2013*

**Chem**

Predict the first order splitting patterns of the indicated proton in the following molecules: CH3CH2CH3 (the H in CH2 is selected) a) quintet b) quartet of quartets c)septet
*April 16, 2013*

**CHEM**

a) Give the major elimination product derived from each of the following elimination reactions. Pay attention to stereochemistry where appropriate. 2-Bromo-3-methylbutane (H3CH2C-O(-)Na(+))-> ethanol [Ethanol is below the arrow while (H3CH2C - ONa) is on top. the plus sign ...
*March 29, 2013*

**CHEM**

Thank you for helping me out! I am having a tough time in this class and this was a big help
*March 29, 2013*

**CHEM**

What would be the carbon containing product in this SN2 reaction? CH3CH2-O(-) + CH3CH2CH2I -> Give the major product: ICH2CH2CH2CH2CH2F (KCN (1 eq)) DMF --> the KCN is on top of the arrow, while the DMF is below the arrow. I could really use some help! thanks!
*March 29, 2013*

**chemistry**

draw all possible z isomers for an alkene with the formula C4H7Br. im having some difficulty, please help
*March 22, 2013*

**Calculus**

If a snowball melts so that its surface area decreases at a rate of 4 cm2/min, find the rate at which the diameter decreases when the diameter is 12 cm.
*March 19, 2013*

**chemistry**

i got the first one easy enough. the reading was interesting. so that leads me to believe b is the correct answer. thank you dr. bob
*February 15, 2013*

**chemistry**

i believe H2C O with the double bond is the only one with a dipole moment
*February 15, 2013*

**chemistry**

!. Which of the following structures would you expect to have a net dipole moment? HC(triple bond)CH NH4+ H2C(double bond)O BCl3 2. Rank the sp, sp2, and sp3 orbitals in order of decreasing (highest to lowest) energy. a)sp> sp2>sp3 b)sp3>sp2>sp c)sp2>sp>sp3 d...
*February 15, 2013*

**chemistry (please someone help)**

oh i did. thank you for your responses!
*February 7, 2013*

**chemistry (please someone help)**

for instance would i draw something like this? the diagonal lines are suppose to be straight lines. H-C-H / H-N-H / H
*February 7, 2013*

**chemistry (please someone help)**

thank you. but when the question asks me to draw out the product am I drawing two structures or one?
*February 7, 2013*

**chemistry (please someone help)**

H3C+ yes thats what the problem says
*February 7, 2013*

**chemistry (please someone help)**

lewis acid or lewis base? then draw the product. H3C^+ :NH3 ----> I'm assuming H3C is the acid and :NH3 is the base? As for drawing out the product I dont know what to do.
*February 7, 2013*

**chemistry**

i believe it wants it drawn out in a lewis structure for the product
*February 7, 2013*

**chemistry**

lewis acid or lewis base? then draw the product. H3C^+ :NH3 ----> I'm assuming H3C is the acid and :NH3 is the base? As for drawing out the product I dont know what to do.
*February 7, 2013*

**Calculus**

Explain, using the theorems, why the function is continuous at every number in its domain. F(x)= 2x^2-x-3 / x^2 +9 A) F(x) is a polynomial, so it is continuous at every number in its domain. B) F(x) is a rational function, so it is continuous at every number in its domain. C) ...
*February 5, 2013*

**math**

120 degrees.
*January 15, 2013*

**physics please help!**

A bat moving at 6.5 m/s is chasing a ﬂying insect. The bat emits a 37 kHz chirp and receives back an echo at 37.65 kHz. At what speed is the bat gaining on its prey? Take the speed of sound in air to be 336 m/s. Answer in units of m/s
*December 8, 2012*

**physics**

Question 4 A 0.9 kg block attached to a spring of force constant 2.1 N/m oscillates with an amplitude of 9 cm. A)Find the maximum speed of the block. Answer in units of m/s B)Find the speed of the block when it is 4.5 cm from the equilibrium position. Answer in units of m/s C)...
*November 29, 2012*

**physics**

it tells me that its incorrect
*November 29, 2012*

**physics**

Three particles of masses 14 kg, 21 kg, and 69 kg are located at the vertices of an equilateral triangle of sides 7 m. A)Find the x-coordinate of the center of gravity of this system with respect to a coordinate system with origin at the 14 kg particle and with the 21 kg ...
*November 4, 2012*

**logical reasoning, math**

a blue box have 5 times as many marbles as a red box. the blue box has 24 more marbles than a red box. how many marbles are in each bx?
*October 24, 2012*

**calculus**

Differentiate the function. y = (Square root x)(x − 10)
*September 20, 2012*

**calculus**

Thank you!!
*September 20, 2012*

**calculus**

never mind I got it but could someone just help me with this one. A(s)= -11/s^6
*September 20, 2012*

**calculus**

Differentiate the function. g(x)= x^2(1-2x) g'(x)= i tried doing 2x(1-2x) 2x-4x^2
*September 20, 2012*

**chem**

I got it. Both have the same answers of water, methanol, ethanol and acetone!
*September 18, 2012*

**physics**

please someone help!!
*September 14, 2012*

**physics**

An object is dropped from a height H above the ground. This free-falling object requires 0.904 s to travel the last 34 m before hitting the ground. From what height H above the ground did the object fall? The acceleration of gravity is 9.8 m/s^2. Answer in units of m i ...
*September 14, 2012*

**physics**

An object is dropped from a height H above the ground. This free-falling object requires 0.904 s to travel the last 34 m before hitting the ground. From what height H above the ground did the object fall? The acceleration of gravity is 9.8 m/s^2. Answer in units of m i ...
*September 14, 2012*

**calculus**

this sentence doesnt look quite right it should look more like this In this situation, the function is f(x) = ? a= ?
*September 14, 2012*

**calculus**

well the question is from what im assuming is trying to find what f(x) is equal to. thats the last line of my question above. it also wants me to find what a is equal to. so to find slope i took the first derivative: y'= 1/ [2sqrt(x)] since x=64 makes this y'=1/(2*8...
*September 14, 2012*

**calculus**

i got a slope of 1/16 is that right?
*September 14, 2012*

**calculus**

its asking for f(x) and a im just trying to figure out how i would go about doing this. thanks for answering me.
*September 14, 2012*

**calculus**

To find the equation of a line, we need the slope of the line and a point on the line. Since we are requested to find the equation of the tangent line at the point (64, 8), we know that (64, 8) is a point on the line. So we just need to find its slope. The slope of a tangent ...
*September 14, 2012*

**calculus**

the program is telling me that is incorrect
*September 12, 2012*

**calculus**

would this just be infinity that they are looking for?
*September 12, 2012*

**calculus**

This problem has two parts but I can only see this so far. I probably over thinking..what is this asking for? How do I answer it? To evaluate lim x→ infinity sqrt(x^2 + 4) *first consider that as x becomes infinitely large x^2+4 -> __?__
*September 12, 2012*

**math**

if youre factoring this then the way you factor the quadratic equation looks like this: (3x^2+5x-2)=0 (3x-1)(x+2)=0 *notice how the the FOIL method works here. then to get x you would take each one and set it to 0. making this x=(1/3) and x=-2
*September 12, 2012*

**calculus**

oh okay i understand now! thank you so much for helping me. i really do appreciate it!
*September 12, 2012*

**calculus**

im pretty sure my first step would be to divide the numerator and denominator by e^x but i dont know where to go after that.
*September 12, 2012*

**calculus**

find the limit. lim (5-e^x)/(5+3e^x) (x-> infinity) how would i go about solving this? thank you in advance to anyone who can help me.
*September 12, 2012*

**physics**

A hot air balloon is traveling vertically upward at a constant speed of 5.3 m/s. When it is 25 m above the ground, a package is released from the balloon. After it is released, for how long is the package in the air? The acceleration of gravity is 9.8 m/s^2. Answer in units of...
*September 9, 2012*

**trig**

A point on the terminal side of an angle theta is given. Find the exact value of the six trigonometric functions of theta: (2,-3)
*May 17, 2012*

**Chemistry**

Using the half reaction potentials calculate the E^o cell for the Ni-Al cell. Ni (aq) + 2e- <-> Ni (s) -0.25v Al3+ (aq) + 3e- <-> Al (s) -1.66v Using that answer determine Ecell for Ni-Al cell when the concentration of Al3+ is 4.00M and the concentration of Ni2+ (...
*April 25, 2012*

**calculus**

Suppose x=4sin(theta, for theta (-pie/2, pie/2). Rewrite(sqrt16-x^2)^3/x^3 (Sorry Im not very good at making symbols. I hope you know what I mean here! if not I can try to rewrite it a different way)
*April 22, 2012*

**Chemistry lab**

Thanks so much and the typo was no big deal I knew what you meant. :) you're a life saver!
*April 11, 2012*

**Chemistry lab**

Thank you for your response! Having all of these numbers confused me. So for part a I'm multiplying 7.410 mL (first equivalence point) by .1523 M. I got 1.129 mmol H3PO4. Then divided it by 10.0mL to get a concentration of 0.113 M H3PO4.
*April 11, 2012*

**Chemistry lab**

1) Using the 1st equivalence point from part a calculate the molarity of the phosphoric acid. Molarity of NaOH = .1523 M Volume of phosphoric acid used 10.0mL Volume at equivalence point 7.410 mL and 14.861 mL 2) Using the 2nd equivalence point from part a, calculate the ...
*April 11, 2012*

**chemistry**

Yes I meant 22mL. How would I go about solving for the Kb?
*April 4, 2012*

**chemistry**

I am giving a titration curve of a weak base and strong acid. The pH on the y scale is from 0-14 and the volume of titrant in mL is from 0-34. It looks like the equivalene point is around 22? The question is: "The above titration curve was obtained when a 10 mL sample of ...
*April 4, 2012*

**chemistry**

There is no Ka value that I see, so I looked it up hopefully on a reliable website. Could you make sure this is correct? 7.2*10^-4 so would this problem be: 7.4*10^-4= (x^2)/ (5.3*10^-2-x) On a calculator I get this number 0.006262587 then -log to get 2.20
*March 29, 2012*

**chemistry**

to find pH
*March 29, 2012*

**chemistry**

pH of HF 5.3*10^-2 M Since HF is a weak acid, I'm not sure which formula to use.
*March 29, 2012*

**chemistry**

Oh okay I thought you used Ka to solve these. That's what I'm doing wrong. I tried looking up the Ka for HF and multiplying it to .280 then take the -log of that number. The reason why I had to different numbers is because I found two different Ka's. If I can't...
*March 29, 2012*

**chemistry**

I keep getting wrong answers for this question. Determine the pH of an HF solution of each of the following concentrations. a) .280 M b) 5.3*10^-2 M c) 2.50*10^-2 M No Ka has been given. I haven't attempted b or c yet because I want to at least solve a first. So far I got ...
*March 29, 2012*

**chemistry lab**

Thank you for your feed back it helped me out greatly!
*March 27, 2012*

**chemistry lab**

Hi, so I did a lab on acids, bases, salts and buffer solutions. After measuring the pH for a .010 M HCl solution I got a pH of 2.50. After doing a calculated pH of .010 M of HCl the answers is 2. My question is why do you think my pH from the experimental is slightly higher ...
*March 27, 2012*

**Science**

Ten grams of ice are heated in a closed container until it turns to steam. What is the mass of the steam?
*March 15, 2012*

**Chemistry **

Kp=1.6 Kp=1.0*10^-4 A<->2B Find the equilibrium partial pressures of A and B B=1.0 atm A=0.0 atm This is what I have so far A 2B 0 1.0 +p -p p 1-p [B]^2/A (1-p)^2/p = 1.6 then got a quadratic equation of p^2+1.6p-1 to get x=.48
*March 12, 2012*

**Chemistry**

I got the same answers for both, but I dont know how to get two pressures from these numbers
*March 12, 2012*

**Chemistry**

if that is correct then i got a value of 1.6 after plugging it in. This is the step that Im not sure what to do.
*March 12, 2012*

**Chemistry**

Not sure what I did there? my x value came to be .3035. Should I plug this number into the (1-p)^2/p
*March 12, 2012*

**Chemistry **

Kp=1.6 Kp=1.0*10^-4 A<->2B Find the equilibrium partial pressures of A and B B=1.0 atm A=0.0 atm This is what I have so far A 2B 0 1.0 +p -p p 1-p [B]^2/A (1-p)^2/p = 1.6 then got a quadratic equation of p^2+1.6p-1 to get x=.48
*March 12, 2012*

**chemistry**

Thank you for answering me! You don't know how much it means to me. I think I'm over thinking this but I need all the help I can get. So for A) I just divided .120/.0431 and got 2.78. It just seems too simple to me haha. For letter C I tried finding the moles of H2S. ...
*March 11, 2012*

**chemistry**

Ammonium bisulfide, NH2HS, forms ammonia NH3, and hydrogen sulfide, H2S through the reaction: NH4HS (s) <--> NH3(g) + H2S(g) Kp value of .120 at 25C in a 5L flask is charged with .300g of H2S at 25C. A) What are the partial pressures of NH3 and H2S at equilibrium, what ...
*March 11, 2012*

**algebra**

Got it. Man that felt good to actually solve a problem after all these years.
*November 21, 2011*

**algebra**

O.k. I'm 42 trying to help my nephew with algebra and lets just say it's been awhile.... Total money $ 101.25 45 more dimes than nickels 3 times as many quarters as dimes. How many nickels, dimes & quarters?
*November 21, 2011*

**Science**

i freaking do not have a clue
*March 24, 2010*

**psychology**

okay thanks
*November 18, 2009*

**psychology**

SO HOW SHOULD I COULD DO BECAUSE ITS ALL CONFUSING TO ME
*November 18, 2009*

**psychology**

EXPLAINING WHAT IS IT THAT I HAVE TO DO BECAUSE IM ALL CONFUSE
*November 18, 2009*

**psychology**

Hi, i need some help in this assigment please can you guys help me Instructiions sources must be cited in APA format. your response should a minimum 1 single spaced page Talent and ambition alone do not predict who will push on to reach a goal and who will give up when going ...
*November 18, 2009*

**math/algabra**

whats x+2+2x=x+10?
*February 7, 2008*

**science**

how many different types of walnut trees are there and what do they look like?
*October 7, 2007*

**math**

There are 27 pigs. The farmer needs to get them into four pens. But all the pens have to have an odd number of pigs. Zero doesn't count as a number.
*September 3, 2007*

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