# Posts by Jessica

Total # Posts: 3,328

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...

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

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!

Chemistry
The answer that was in my answer key was 2.83 but I got 3.48. Is there something wrong in the calculations?

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

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.

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?

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

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

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

Chemistry (Follow up post - Dr.BOB22)
The first link seems to be broken.

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...

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 ...

Chemistry
Thank you. My apologies for the repeated postings.

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 ...

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 ...

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 ...

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 ...

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

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

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.

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?

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 ...

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

Mathematics
Thanks

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) ...

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.

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.

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...

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 ...

Chemistry
Calculate the pH of the following 0.0500 M H3AsO4 and 0.0500 M NaH2AsO4?

Chemistry
Calculate the pH of the following 0.0500 M H3AsO4 and 0.0500 M NaH2AsO4?

chemistry
Calculate the pH of a solution made with 0.0600 M carbonic acid, H2C03 and 0.0300 M NaHCO3.

Chemistry
Calculate the pH of a solution made with 0.240 M H3PO3 and 0.480 M NaH2PO3.

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':

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?

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 ...

u.s. court system part 1

finance
how long will it take to double my investment with 2500 at 4% annually

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?

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 ...

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...

Chemistry
What caroxylic acid and alcohol is needed to produce isopentyl propionate?

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?

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) ...

Chemistry
What carboxylic acid and alcohol is needed to produce isobutyl propionate?

Chemistry
What carboxylic acid and alcohol is needed to produce propyl acetate?

Chemistry
What caroxylic acid and alcohol is needed to produce isopentyl propionate?

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

Mathematics
Determine the quadratic equation whose solutions are: 3 and -2. Explain your solution

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

Math
I'm working on this project and i don't even know what its asking me

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.

geometry
DEFG is an isosceles trapezoid. Find the measure of E.

math
Okie! I always suppose to have the same homework! Haha. Ok, lets get serious. \$3.50t is the same as \$3.50 X t. In this problem, t=5 pencils Situation: Josh was buying t pencils. T is equal to 5 pencils. Each pencil cost \$3.50. How much money will Josh need to pay if he buys 5 ...

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?

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 ...

no affence esha but actually for that answer i would say that's wrong cause if you add it correctly its actually 1,442

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?

math
x + y = 40,000 .04x + 0.08y = 2,720 x = 40,000 - y .04(40,000 - y) + 0.08y = 2,720 1,600 - .04y + 0.08y = 2,720 1,600 + 0.04y = 2,720 0.04y = 1,120 y = 28,000 x = 40,000 - 28,000 x = 12,000 y = 28,000

Calculus
I get 2(sqrt3/2)(1-(3/4)1^(4/3)) But that's not the answer.

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 don...

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 ...

Calculus

I don't know what to do for this problem.

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 don't 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(...

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 don...

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 don...

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 ...

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 ...

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...

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 ...

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...

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 ...

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

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

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 ...

Geography
Graticules on small scale map represents ________ and ______. Graticules on large scale map represents ________ and ______.

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?

english
Please tell me the anthropological perspective. Is the culture, the cross-disciplinary discipline etc? Thanks!

writing essay
Well, you know what I would recommend you to contact Supreme essay service whenever you need some help in writing. Those guys are real professionals in what they do. The answer is 'B'. All the best!

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?

chemistry
yes thank you the 1st one was considered strong :)

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

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

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.

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

Mechanics
When a problem is statically indeterminate, what additional equations do you need to solve?

Physics
i don't get how to get rid of all the t's...

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?

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?

Mechanics
What does a polar moment of inertia depend on?

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