Sunday

December 21, 2014

December 21, 2014

Total # Posts: 2,715

**Chemistry**

Regarding your first post, I believe I used aspirin as the weak acid. In a previous problem which was related to these problems, it stated "aspirin is a weak acid with a Ka of 3.0x10^-5"
*November 26, 2011*

**Chemistry**

Sorry, one more question. For .........RNH2 + HCl ==> RNH3^+ + Cl^- initial...0....................... added...........0 added..........2.0 added..........4.0 etc change..................... the initial RNH2 is 0? Shouldn't it be the initial moles in the problem (....
*November 26, 2011*

**Chemistry**

For problem 1, if it were changed to 20 mL of the .07222M aspirin solution and 5mL of .2M NaOH, how would solving it differ? I tried ...........HA + NaOH ==> NaA + H2O initial..0014444.................. add..............001............ change...-.001.-.001.....+.001...+.001...
*November 26, 2011*

**Chemistry**

1.Calculate the pH of a solution prepared by mixing 20mL of the .07222M aspirin solution with 10mL of .2M NaOH. 2. Calculate the pH for the titration of 40mL of .1M solution of C2H5NH2 with .1M HCl for a)0 mL added and b)20 mL added c)40 mL added d)50mL added. Kb= 6.4x10^-4
*November 26, 2011*

**Chemistry**

For the ICE box, you are supposed to use the molarity of the aspirin. I did not realize that. Thank you so much for your help!
*November 26, 2011*

**Chemistry**

The answer that was in my answer key was 2.83 but I got 3.48. Is there something wrong in the calculations?
*November 26, 2011*

**Chemistry**

Aspirin is a weak acid with a Ka of 3.0x10^-5. Find the pH of a solution by dissolving .65g of aspirin in water and diluting it to 50mL. You can use RCOOH to represent aspirin. Molecular weight of aspirin is 180g/mol
*November 26, 2011*

**e-business**

In about 100 words, explain what kinds of features of characteristics a midsize business would seek in its electronic commerce software that would not matter to a smaller business.
*November 25, 2011*

**math**

How many ml of a 34% sugar solution must be mixed with 2 ml of a 54% sugar solution to make a 38% solution?
*November 20, 2011*

**Mathematics**

Given that a√b^2-c = 5k, find the value of: 1. k when a = 3, b = 6 and c = 20 2. c when a = 4, b = 7, and k = 11 Explain your working please
*November 16, 2011*

**physics**

A shopper in a supermarket pushes a loaded 31 kg cart with a horizontal force of 12 N. The acceleration of gravity is 9.81 m/s2 . a) Disregarding friction, how far will the cart move in 3.6 s, starting from rest? Answer in units of m
*November 14, 2011*

**physics**

A shopper in a supermarket pushes a loaded 31 kg cart with a horizontal force of 12 N. The acceleration of gravity is 9.81 m/s2 . a) Disregarding friction, how far will the cart move in 3.6 s, starting from rest? Answer in units of m
*November 14, 2011*

**Chemistry (Follow up post - Dr.BOB22)**

The first link seems to be broken.
*November 13, 2011*

**Chemistry (Follow up post - Dr.BOB22)**

Oh, I'm sorry. I wasn't really trying to put them together. I just wanted you to see what I understood about ionization. And then ask my question. Do you think you could help me understand lasers and plasma arcs connection to ionization levels? or point me to a website...
*November 13, 2011*

**Chemistry (Follow up post - Dr.BOB22)**

Ionization is when an electron is removed from an atom and ionization energy is the energy required to do this. "Electrons stream from the negative electrode to the positive electrode. In the process of moving from one electrode to the other they knock electrons in the ...
*November 13, 2011*

**Chemistry**

Thank you. My apologies for the repeated postings.
*November 13, 2011*

**Chemistry**

I have an assignment to 'Research ionization energy levels and come up with 3 real world applications' and was told to look up lasers, plasma arcs and neon lights. Hours later, (lol) I'm still having a little trouble. Is there any way someone can explain the ...
*November 13, 2011*

**CHEMISTRY**

Ionization is when an electron is removed from an atom and ionization energy is the energy required to do this. "Electrons stream from the negative electrode to the positive electrode. In the process of moving from one electrode to the other they knock electrons in the ...
*November 13, 2011*

**CHEMISTRY**

I have an assignment to 'Research ionization energy levels and come up with 3 real world applications' and was told you look up lasers, plasma arcs and neon lights. Hours later, (lol) I'm still having a little trouble. Is there any way someone can explain the ...
*November 13, 2011*

**CHEMISTRY**

I have an assignment to 'Research ionization energy levels and come up with 3 real world applications' and was told you look up lasers, plasma arcs and neon lights. Hours later, (lol) I'm still having a little trouble. Is there any way someone can explain the ...
*November 13, 2011*

**Chemistry**

I'm still having a little trouble. Is there any way you can explain the connection between lasers, plasma arcs and neon lights?
*November 13, 2011*

**Chemistry**

Do these three things have ionization energy levels? To be honest, I'm not quite sure how ionization works.
*November 13, 2011*

**Chemistry**

I have an assignment to 'Research ionization energy levels and come up with 3 real world applications'. I'm not so sure how to do this. Any help would be appreciated.
*November 13, 2011*

**college physics**

What distance will a 10 hp motor lift a 2000 lb elevator in 30 s? What was the average velocity of this elevator during the lift?
*November 11, 2011*

**Physics**

An 83.2-kg propeller blade measures 2.24m end to end. Model the blade as a thin rod rotating about its center of mass. It's initially turning at 175rpm. Find the blade's angular momentum, the tangential speed at the blade tip, and the angular acceleration and torque ...
*November 11, 2011*

**Mathematics**

If a piece of wood is 5 cm longer than a second piece, and 3/4 of the second piece is equal to 3/5 of the first, what is the length of the second piece? Explain your workings
*November 9, 2011*

**Mathematics**

Thanks
*November 9, 2011*

**Chemistry**

Classify the possible combinations of signs for a reaction's ∆H and ∆S values by the resulting spontaneity. A) Spontaneous as written at all temperatures. B) Spontaneous in reverse at all temperatures. C) Spontaneous as written above a certain temperature. D) ...
*November 9, 2011*

**Chemistry**

Calculate the pH of 100.0 mL of .0200 M pyruvic acid and .0600 M sodium pyruvate Calculate the pH of 100.0 mL of .0200 M pyruvic acid and 0.0600 M sodium pyruvate with 0.250 millimoles of H3O+ added.
*November 8, 2011*

**math PLEASE HURRY**

there are 24 students in a science class. Mr. Sato will give each pair of students 3 magnets. So far, Mr. Sato has given 9 pairs of students their 3 magnets. homw many more magents does Mr. Sato need so that each pair of students has excatly 3 magnets.
*November 8, 2011*

**math**

a developer wants to enclose a rectangular grassy lot that borders a city street for parking. If the developer has 336 feet of fencing and does not fence the side along the street, what is the largest area that can be enclosed and what are the dimensions that give this maximum...
*November 8, 2011*

**algebra**

I have no clue where to begin on this problem. Can some one help me please. One demographer believes that the population growth of a certain country is best modeled by the function P (t) =15 e^.08t, while a second demographer believes that the population growth of that same ...
*November 8, 2011*

**Chemistry**

Calculate the pH of the following 0.0500 M H3AsO4 and 0.0500 M NaH2AsO4?
*November 8, 2011*

**Chemistry**

Calculate the pH of the following 0.0500 M H3AsO4 and 0.0500 M NaH2AsO4?
*November 8, 2011*

**chemistry**

Calculate the pH of a solution made with 0.0600 M carbonic acid, H2C03 and 0.0300 M NaHCO3.
*November 8, 2011*

**Chemistry**

Calculate the pH of a solution made with 0.240 M H3PO3 and 0.480 M NaH2PO3.
*November 8, 2011*

**6th grade math**

A: 5/100 is exactly 0.05, not less. 0.05 is 5%, not 50% B. 0.7 is exactly 1/7, but 1/7 is not 10%. 10% is 1/10 C. 2/10 is 20%, not 25% and 0.9 is 90%, not 25% D. 0.3 is not 36%, it's 30%. 36/10 is 3.6, not 36%, which is 0.36. None of them seem correct. D':
*November 6, 2011*

**science**

On Apollo missions to the Moon, the command module orbited at an altitude of 150 above the lunar surface. How long did it take for the command module to complete one orbit?
*November 3, 2011*

**physics**

The drawing shows a hydraulic system used with disc brakes. The force vector F is applied perpendicularly to the brake pedal. The pedal rotates about the axis shown in the drawing and causes a force to be applied perpendicularly to the input piston (radius = 9.39 10-3 m) in ...
*November 1, 2011*

**u.s. court system part 1**

answers to penn foster exam-40600900
*October 30, 2011*

**finance**

how long will it take to double my investment with 2500 at 4% annually
*October 29, 2011*

**Physics**

A rocket, 8975 kg, traveling at 1255 m/s East explodes into two pieces. if one piece, 2450 kg, moves at 750.0 m/s due south, what is: the mass of the second piece? the momentum of the second piece? the velocity of the second piece?
*October 27, 2011*

**statistics**

In 2006, the General Social Survey asked, "Do you see yourself as someone that tends to be lazy?" For this question, 20 people said that they definitely did out of 1513 randomly selected people. What is the 95% confidence interval for the proportion of all Americans ...
*October 27, 2011*

**Physics**

A proton, moving in negative y-direction in a magnetic field , experiences a force of magnitude F, acting in the negative x direction. a) What is the direction of the magnetic field producing force? b) Does your answer change if the word proton is replaced by electron? I get a...
*October 25, 2011*

**Chemistry**

What caroxylic acid and alcohol is needed to produce isopentyl propionate?
*October 24, 2011*

**Word Problem**

A developer wants to enclose a rectangular grassy lot that borders a city street for parking. If the developer has 212 feet of fencing and does not fence the side along the street, what is the largest area that can be enclosed?
*October 24, 2011*

**BEDMAS with decimals**

30.8
*October 24, 2011*

**Physics**

An isolated segment of wire of length L=4.50 m carries a current of magnitude i=35.0 A at an angle theta=50.3 degrees with respect to a constant magnetic field with magnitude B= 6.70E-2 T. What is the magnitude of the magnetic force on the wire? a) 2.66 N b) 3.86 c) 5.60 N d) ...
*October 24, 2011*

**Chemistry**

What carboxylic acid and alcohol is needed to produce isobutyl propionate?
*October 24, 2011*

**Chemistry**

What carboxylic acid and alcohol is needed to produce propyl acetate?
*October 24, 2011*

**Chemistry**

What caroxylic acid and alcohol is needed to produce isopentyl propionate?
*October 24, 2011*

**Physics**

Suppose that the magnetic field o fthe Earth were due to a single current moving in a circle of radius 2988 km through the earth’s molten core. The strength of the Earth’s magnetic field on the surface near a magnetic pole is about 6.00E-5 T. About how large a ...
*October 23, 2011*

**Physics**

1)A wire is carrying a current, i, in the positive y-direction. The wire is located in a uniform magnetic field, B, oriented in such a way that the magnetic force on the wire is maximized. The magnetic force acting on the wire, FB, is in the negative x direction. What is the ...
*October 23, 2011*

**Physics**

Please help me with these choose the best answers since I'm not sure of my answers. A current element produces a magnetic field in the region surrounding it. at any point in space, the magnetic field produced by this current element points in a direction that is a) radial ...
*October 23, 2011*

**Physics**

1)A wire is carrying a current, i, in the positive y-direction. The wire is located in a uniform magnetic field, B, oriented in such a way that the magnetic force on the wire is maximized. The magnetic force acting on the wire, FB, is in the negative x direction. What is the ...
*October 23, 2011*

**Physics**

Please help me with these choose the best answers since I'm not sure of my answers. A current element produces a magnetic field in the region surrounding it. at any point in space, the magnetic field produced by this current element points in a direction that is a) radial ...
*October 23, 2011*

**Physics**

1)A wire is carrying a current, i, in the positive y-direction. The wire is located in a uniform magnetic field, B, oriented in such a way that the magnetic force on the wire is maximized. The magnetic force acting on the wire, FB, is in the negative x direction. What is the ...
*October 23, 2011*

**Physics**

1)A wire is carrying a current, i, in the positive y-direction. The wire is located in a uniform magnetic field, B, oriented in such a way that the magnetic force on the wire is maximized. The magnetic force acting on the wire, FB, is in the negative x direction. What is the ...
*October 23, 2011*

**Physics**

1)A wire is carrying a current, i, in the positive y-direction. The wire is located in a uniform magnetic field, B, oriented in such a way that the magnetic force on the wire is maximized. The magnetic force acting on the wire, FB, is in the negative x direction. What is the ...
*October 23, 2011*

**Mathematics**

Determine the quadratic equation whose solutions are: 3 and -2. Explain your solution
*October 21, 2011*

**Mathematics**

In 11 years, the age of Russel will be half of the square of the age he was 13 years ago. Find his present age. Explain your solution
*October 21, 2011*

**Physics**

Two long parallel wires separated by a distance, d, carry currents in opposite directions. If the left-hand wire carries a current i/2, and the right-hand wires carries a current i, determine where the magnetic field is zero.
*October 20, 2011*

**geometry**

DEFG is an isosceles trapezoid. Find the measure of E.
*October 20, 2011*

**math**

a candy sells chocolate fudge for $4.50 for the first pound and $2.50 for each additional pound. how many pounds could be purchased with $29.00?
*October 18, 2011*

**physics**

At the airport, you pull a 18 kg suitcase across the floor with a strap that is at an angle of 41° above the horizontal. Find the normal force and the tension in the strap, given that the suitcase moves with constant speed and that the coefficient of kinetic friction ...
*October 18, 2011*

**math help me please!!!!!!!!!!!!!!!!**

no affence esha but actually for that answer i would say thats wrong cause if you add it correctly its actually 1,442
*October 18, 2011*

**Chemistry Lab**

Suppose for the reaction of Cu(NO3)2 + NaOH, you have not added enough sodium hydroxide to precipitate all the copper as copper hydroxide Cu(OH)2. a)How could you tell that not all the copper had precipitated? b)what effect would this have on the final yield?
*October 18, 2011*

**Calculus**

I get 2(sqrt3/2)(1-(3/4)1^(4/3)) But that's not the answer.
*October 13, 2011*

**Calculus**

Find the volume of the solid obtained by rotating the region bounded by y=x^3, y=1, and the y-axis and whose cross-sections perpendicular to the y axis are equilateral triangles. I asked this same question for the y-axis around the x-axis (Thanks for the explanation) but I ...
*October 13, 2011*

**Calculus**

I don't see any error, but webwork just says y= , I can't enter anything besides what y is supposed to be. The slope I took was a method I found in my book but it only says that, how to take the slope, and I don't even know if I had that right. But I cant enter ...
*October 13, 2011*

**Calculus**

Webwork asks me to enter an answer for y=
*October 13, 2011*

**PLEASE I really need help!!!**

I dont know what to do for this problem.
*October 13, 2011*

**Calculus**

Find the equation (in terms of x and y) of the tangent line to the curve r=3sin3(theta) at theta=pi/4. I dont know if I'm taking the right approach for this question but her goes what I did: I found the slope I got (9(-1/2)(sqrt3/2)+3(sqrt3/2)(1/2))/(9(-1/2)(1/2)-3(sqrt3/2...
*October 13, 2011*

**Calculus**

Find the volume of the solid obtained by rotating the region bounded by y=x^3, y=1, and the y-axis and whose cross-sections perpendicular to the y axis are equilateral triangles. I asked this same question for the y-axis around the x-axis (Thanks for the explanation) but I ...
*October 13, 2011*

**Calculus**

Find the volume of the solid obtained by rotating the region bounded by y=x^3, y=1, and the y-axis and whose cross-sections perpendicular to the y axis are equilateral triangles. I asked this same question for the y-axis around the x-axis (Thanks for the explanation) but I ...
*October 13, 2011*

**Calculus**

Find the volume of the solid obtained by rotating the region bounded by y=x^3, y=1, and the y-axis around the x-axis. What I did was: V=ç(0,1)pi(1-x^3)^2 dx v=pi(x^7/7-x^4/2+x) and I evaluated it for one since 0 is just going to be 0. and I got 9pi/14 The answer ...
*October 13, 2011*

**Calculus**

Find the volume of the solid obtained by rotating the region bounded by y=x^3, y=1, and the y-axis around the x-axis. What I did was: V=ç(0,1)pi(1-x^3)^2 dx v=pi(x^7/7-x^4/2+x) and I evaluated it for one since 0 is just going to be 0. and I got 9pi/14 The answer ...
*October 13, 2011*

**English**

I was wondering if you could help me revise this? Questions plague the mind of many readers of why exactly Tessie Hutchinson was stoned in Shirley Jackson’s, “The Lottery”. This gruesome tale tells of an innocent woman stoned in a small village of 300 people. In...
*October 11, 2011*

**physics**

Two blocks with mass m1 = 7.2 and m2 = 7.7 are connected by a massless string over a frictionless and massless pulley. The angle of the incline is equal to 45.0. The kinetic coefficient of friction between m1 and the incline is 0.22. What is the minimum value of the static ...
*October 9, 2011*

**English**

I am writing this essay about Shirley Jackson's "The lottery" My essay is supposed to be about i think i want to talk about stoning in south africa( how long it lasted, if it still takes place, was it for punishment or for no reason) and the second body paragraph...
*October 9, 2011*

**English Please help**

i have an essay and ive been researching the topic like for freaking ever and i havent been able to fine anything "scholarly" through collins(my college's) libraries searching databases do you know any scholarly websites..?? Like literally ive been researching ...
*October 9, 2011*

**healthcare**

required annually pap smear: government is limiting those who have medicaid only to recevie the pap smear only every 3rd year but those you have private insurance it will cover it annually . what do you think opinions
*October 8, 2011*

**Chemistry**

I got 9.25527 for the pKa then for the Henderson-Hasselbalch equation: 9.00=9.25527+log(.600/acid) 10^(-.25527)=(.600/acid) .5556/.600M=acid acid=.925925...M molarity (.925925)*2.10L= 1.94 moles of NH4Cl 1.94 moles *53.4 grams=104.02g of NH4Cl
*October 8, 2011*

**Chemistry**

How many grams of dry NH4Cl need to be added to 2.10L of a 0.600M solution of ammonia,NH3 , to prepare a buffer solution that has a pH of 9.00? Kb for ammonia is 1.8x10^-5. I just wanted to make sure I dd this write, can you please check my work? Thank you!!!! I found the pKa ...
*October 8, 2011*

**Geography**

Graticules on small scale map represents ________ and ______. Graticules on large scale map represents ________ and ______.
*October 7, 2011*

**physics**

2. A tiger jumps horizontally off of a 1.7 meter tall rock with a velocity of 3.2. How far from the base of the rock does the tiger land?
*October 7, 2011*

**english**

Please tell me the anthropological perspective. Is the culture, the cross-disciplinary discipline etc? Thanks!
*October 7, 2011*

**Biology**

Using Darwin’s Theory of Evolution, describe how Eukaryotic cells could have developed from Prokaryotic cells. What advantages would the Eukaryotic cells have over the Prokaryotic?
*October 6, 2011*

**chemistry**

yes thank you the 1st one was considered strong :)
*October 5, 2011*

**chemistry**

a)H2SO4 b)CuS c)HF d)Zn(NO3)2 Which are strong, weak, or non electrolytes. I was think A was strong B and C were weak and D is non
*October 5, 2011*

**Chemistry**

Find the standard entropy (S^0) of ice at 25K. delta Hfus = 6009 J/mol and Cp of ice = 38 J/molK.
*October 5, 2011*

**Algebra**

The larger of two numbers is 23. if three times the number is 5 more than eight times the smaller, find the smaller number.
*October 4, 2011*

**Physics**

A motorist travelling at 107 km/hr is being chased by a police car at 133 km/hr. If the police car starts from 3.0 km back, how long does it take to catch the motorist? Leave time in hours
*October 4, 2011*

**Mechanics**

When a problem is statically indeterminate, what additional equations do you need to solve?
*October 4, 2011*

**Physics**

i dont get how to get rid of all the t's...
*October 4, 2011*

**Physics**

A hot air balloon is rising at a constant velocity of 13.3 m/s. When the balloon is at a height of 15 m, a heavy object is dropped overboard. IF air resistance on the object is neglected, how long does it take for it to reach the ground?
*October 4, 2011*

**Physics**

You are pulling your little sister on her sled across an icy (frictionless) surface. When you exert a constant horizontal force of 113 N, the sled has an acceleration of 1.3 m/s2 If the sled has a mass of 6.6 kg, what is the mass of your little sister?
*October 4, 2011*

**Mechanics**

What does a polar moment of inertia depend on?
*October 3, 2011*

**Math**

A triangle and trapezoid share a 15 inch base and a height of 10 inches. For what values of b is the area of the trapezoid less than twice the area of the triangle?
*October 3, 2011*

**biology**

what is activation energy?
*October 3, 2011*

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