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December 22, 2014

Posts by help


Total # Posts: 966

Chemistry
This is what I did: moles of H2O = 3.88 delta H rxn = -2044.02 (3.88 moles)(6.01 kJ/mol) = 23.359 kJ (3.88 moles)(75.291 J/mol/C) = 29.263 kJ 23.359kJ + 29.2636 kJ = 29.286 kJ (44 g of C3H8)(29.286kJ/-2044.02kJ) = 0.6304 g But I think I did something wrong??
January 24, 2012

Chemistry
How many grams of propane must be burned to provide the heat needed to melt a 70.0-g piece of ice...? How many grams of propane must be burned to provide the heat needed to melt a 70.0-g piece of ice (at its melting point) and bring the resulting water to a boil (with no ...
January 24, 2012

Chemistry
Thanks
January 23, 2012

Chemistry
Knowing that delta Hvap for water is 40.7 kJ/mol, calculate Pvap of water at 46 C
January 23, 2012

math
Bart had an income of $38,250 last year. If the inflation rate is 4.5%, what is his purchasing power?
January 23, 2012

math
If your annual income from a part-time job is $4523, and the inflation rate is 6 percent, what is the purchasing power of your income?
January 23, 2012

math
Let C = 2.32 N + 34180 represent the cost (C) of raising a child to 18 years of age, on an income (N). If the cost is $120,000, what is the income?(
January 23, 2012

math
You spend $685 a month on living expenses. If your monthly income is $1500, what percent of your income do you spend on living expenses?
January 23, 2012

math
Una makes $64 a week, plus 15 percent of the cost of meals that she serves. Use the equation, y = 0.15x + 64, to predict what she makes in a week when she serves $355 worth of meals
January 23, 2012

civics
@writeacher ...i'm still confused.
January 21, 2012

civics
Which is NOT a responsibility of the Department of Agriculture? 1. The opening of foreign markets to U.S. agricultural products 2. To oversee federal anti-hunger programs 3. The designation of lands for private and public use =4. Support for farmers with agricultural research
January 21, 2012

Civics
Which is NOT a responsibility of the Department of Agriculture? 1. The opening of foreign markets to U.S. agricultural products 2. To oversee federal anti-hunger programs =3. The designation of lands for private and public use 4. Support for farmers with agricultural research
January 21, 2012

Physics!!!
The electric field everywhere on the surface of a charged sphere of radius 0.260 m has a magnitude of 545 N/C and points radially outward from the center of the sphere. (a) What is the net charge on the sphere?
January 20, 2012

Physics!!!
The electric field everywhere on the surface of a charged sphere of radius 0.260 m has a magnitude of 545 N/C and points radially outward from the center of the sphere. (a) What is the net charge on the sphere?
January 20, 2012

Math
If your annual income from a part-time job is $2,698, and the inflation rate is 4 percent, what is the purchasing power of your income?
January 19, 2012

MAth
Dan bought a home theater system for $178.99 on the installment plan. The terms of the contract said that he would pay $35 a month for six months. How much are his total payments?
January 18, 2012

Algebra 1
Please help me find the answer to this problem. it would be nice to have the details to how you came by the answer: Radical of 3/4 + radical of 1/3 your help is greatly appreciated
January 6, 2012

chem
you need to make .80 M solution of NiSO4 (aq). How many grams of NiSO4 * 6H2O should you put into a .50 L volumetric flask?
December 12, 2011

Physics
The moment of inertia of an asteroid rotating about its own axis is 5.00 ! 10 4 kg"m2. Its angular velocity is 40.0 rad/s. If a force acts on the asteroid for 0.100 s, increasing the angular velocity to 48.0 rad/s, find its magnitude
December 9, 2011

Physics
A 6110-kg bus traveling at 20.0 m/s can be stopped in 24.0 s by gently applying the brakes. If the driver slams on the brakes, the bus stops in 3.90 s. What is the average force exerted on the bus in both these stops?
December 9, 2011

Physics
Analyze the collision of a baseball with a bat. During which portion of the collision does the baseball’s velocity reach zero? a. before the collision b. during the collision c. one second after the collision d. one-hundredth of a second after the collision
December 9, 2011

Physics
Which conditions will result in the smallest change in momentum? a. a large force over a long time period b. a large force over a short time period c. a small force over a long time period d. a small force over a short time period
December 9, 2011

Physics
A rocket leaves a launch pad at liftoff with a great deal of upward momentum. What was initially given downward momentum? a. the launch pad b. the astronauts aboard the rocket c. the expelled fuel d. the entire Earth
December 9, 2011

Physics
A 0.140-kg baseball is pitched horizontally at 36.7 m/s. When a player hits the ball, it moves at the same speed, but in the opposite direction. If the bat and the ball are in contact for 0.450 ms, calculate the average force the bat exerts on the ball.
December 9, 2011

Physics
Candona strikes a 0.055-kg golf ball with a force of 260 N. If the ball moves with a velocity of 65 m/s, calculate the time the ball is in contact with the club.
December 9, 2011

Physics
A rocket expels gases at a rate of 1.30 x 10^3 kg/s with a speed of 3.00 x 10^4 m/s. What is the force exerted on the rocket?
December 9, 2011

Physics
A lump of clay with a mass of 5.0 ! 10-2 kg is thrown toward a wall with a velocity of 3.0 m/s. The clay bounces off the wall with a velocity of #0.5 m/s. What is the impulse on the clay? If the clay in the previous problem impacted the wall for 5.0 ms, what was the average ...
December 8, 2011

Calculus
A 727 jet needs to attain a speed of 200 mph to take off. If it can accelerate from 0 to 200 mph in 30 seconds, how long must the runway be? (Assume constant acceleration)
December 8, 2011

Physics
A helium balloon lifts a basket and cargo of total weight 2250 N under standard conditions, at which the density of air is 1.29 kg/m3 and the density of helium is 0.178 kg/m3 . What is the minimum volume of the balloon? The acceleration of gravity is 9.81 m/s2 . Answer in ...
December 5, 2011

chemistry
A solution of sulfuric acid in water that is 25% H2SO4 by mass has a density of 1178 g/ml. Which expression gives the molarity of this solution?
November 16, 2011

speech
Describe a scenario in which one would expect an opposed audience. Explain context
November 14, 2011

Chemistry
The primary reason for forming multiple bonds when manipulating electron dot structures is:
November 14, 2011

Chemistry
Ionic bonding typically occurs when a ______________ bonds with a ______________
November 14, 2011

math
. A project management consultant estimated that if a particular project was completed, that t years after its date of completion, P thousand persons would be direct beneficiaries of the project, where P (t) = t3/3 - 5t2 +20t, 0<t<12 For what value of t will the maximum ...
November 8, 2011

Chemistry
Hi there - My labs and lectures aren't in synch at the moment so we are now doing a prelab that is asking for info I haven't been taught yet uggg... The prelab question I'm having trouble with is as follows: What is the volume at STP for 0.415 g of argon gas? Also...
October 29, 2011

Math
Find three ordered pairs that satisfy the equation. y = x+2 (0,1)(0,3)(2,0)
October 28, 2011

math
Thanks, I was close! I'm not that good with plotting graphs.
October 28, 2011

math
Graph the line! y=5x+2 the plot point that i came up with are (0,2)(2,8) is this correct?
October 28, 2011

Math
yes
October 28, 2011

math
Find the amount of compound interest earned in an account that opens with $23,000, earns 3.3% interest compounded daily, and is held for 25 years. Assume 360 days in a year.
October 27, 2011

math
6950*.105=525 is this correct?
October 27, 2011

math
Find the ending balance in an account that opens with $6,950, earns 10.5% interest compounded monthly, and is held for 15 years.
October 27, 2011

Math
Find the ending balance in an account that opens with $5,000, earns 7.5% interest compounded quarterly, and is held for 5 years.
October 27, 2011

Chemistry
Complete this table of values for four aqueous solutions at 25 °C. Solution A: [H+]=0.0093M [OH-]=? pH=? pOH=? Solution B: [H+]=?[OH-]=1.4e-6M pH=? pOH=? Solution C: [H+]=?[OH-]=? pH=5.36 pOH=? Solution D: [H+]=?[OH-]=? pH=? pOH=10.14
October 20, 2011

Chemistry
See above what?
October 20, 2011

Chemistry
Complete this table of values for four aqueous solutions at 25 °C. Solution A: [H+]=0.0093M [OH-]=? pH=? pOH=? Solution B: [H+]=?[OH-]=1.4e-6M pH=? pOH=? Solution C: [H+]=?[OH-]=? pH=5.36 pOH=? Solution D: [H+]=?[OH-]=? pH=? pOH=10.14
October 20, 2011

Chemistry
When a solution is made from 1.0 g of KI and 90 mL of water, what is its molarity?
October 20, 2011

Chemistry
If 4.0 g of hydrogen and 10.0 g of oxygen are mixed according to the equation 2 H2 + O2 = 2 H2O, which is the limiting reagent?
October 20, 2011

chemistry
How many grams of HCl are produced according to the following equation, H2 + Cl2 = 2 HCl, when 4.0 g of hydrogen reacts completely?
October 20, 2011

Healthcare professionals
Hospitals frequently seek ways to ensure survival. Sometimes an adversarial climate cannot be avoided when the action that is being considered is controversial. For example, a hospital may seek to expand its market reach by opening an inpatient drug treatment facility in a ...
October 20, 2011

chemistry
how many milliliters of concentrated NaOH(19.3 M) are needed to make 8.00 L of 0.25 M base solution?
October 20, 2011

Math
e.) 22, 344,579.06 a.) 1, 333.8 c.) 4.44 b) 2.97 d) 2.05 can you please put this in order from least to greatest in decimal form
October 18, 2011

math
Help please
October 18, 2011

math
e.) 22, 344,579.06 a.) 1, 333.8 c.) 4.44 b) 2.97 d) 2.05 can you please put this in order from least to greatest in decimal form
October 18, 2011

France
thank you
October 16, 2011

France
What is France most important for?
October 16, 2011

physics
light travels at a constant speed of 3x10^11 centimeters/sec. how long does it take light to reach the earth a distance of 1.5x10^8 kilometers give your answer in seconds and minutes.
October 15, 2011

Peacocks
oh thank you so much Ms. sue and i researched and found out more about them too
October 13, 2011

Peacocks
how is the peacock adaptation effective ?
October 13, 2011

Peacocks
thanks MS.sue
October 13, 2011

Peacocks
Why are male peacocks colorful? How is it an effective adaption?
October 13, 2011

Physics
A hovercraft of mass 69.0 kg can move on a horizontal surface, the x-y plane. A single unbalanced force acts on the hovercraft, but the size of the force is unknown. The hovercraft initially has a velocity of 5.0 m/s in the positive x direction and some time later has a ...
October 5, 2011

Physics
The driver of a 1350 kg car, initially traveling at 10.6 m/s, applies the brakes, bringing the car to rest in a distance of 15.0 m. Find the net work done on the car. Not sure how to set this problem up.
October 5, 2011

chemistry
is the lost in mass O? or H2O? sorry.
October 4, 2011

chemistry
An unknown mixture containing KClO3 was added to an ignition tube weighting 41.960g, The tube and mixture was then found to weight 43.772g. After the first heating, the tube and its contents weighed 43.621g. After the second and third heatings, it weighed 43.332g. 1)What mass ...
October 4, 2011

chemistry
sodium borohydride (NaBH4) is used industrially in many organic syntheses. one way to prepare it is by reacting sodium hydride with gaseous diborone. Assuming an 86.8% yield,how many grams of NaBH4 can be prepared by reacting 7.98g of sodium hydride and 8.16g of diborone? i ...
October 4, 2011

Physics
One boat tows another boat by means of a tow line, which is under a constant tension of 495 N. The boats move at a constant speed of 4.75 m/s. How much work is done by the tension in 1.10 min? Not sure how to apply the work-energy theorem. I assume velocity needs to be ...
October 3, 2011

Importrant
No problemo
October 3, 2011

Importrant
Thanks Ms.Sue for all your help your the best helper ever.
October 3, 2011

Importrant
ii.) I’ve missed more than 9000 shots in my career. I’ve lost almost 300 games. 26 times, I’ve been trusted to take the game winning shot and missed. I’ve failed over and over and over again in my life. And that is why I succeed.” – M____________ ...
October 3, 2011

Quotes
Thanks Ms.sue But now i just need to awnser ii) and ii) and thanks for the feedback i used it.
October 3, 2011

Quotes
i.) When elephants fight, it’s the grass that suffers ii.) I’ve missed more than 9000 shots in my career. I’ve lost almost 300 games. 26 times, I’ve been trusted to take the game winning shot and missed. I’ve failed over and over and over again in my ...
October 3, 2011

Physics
Tarzan, who weighs 917 N, swings from a vine through the jungle. How much work is done by the tension in the vine as he drops through a vertical distance of 3.85 m? Simply calculating; W=(917N)*(3.85m)= 3530.45 J Isn't working, I'm not sure how to apply the work ...
October 3, 2011

social studies
same its D
October 3, 2011

math
thanks jackie
September 29, 2011

math
need help please help me
September 29, 2011

math
A bumblebee can flap its wings 200 times per second. About how many time times can it flap in l000 min.
September 29, 2011

Physics
I need help figuring this out. I am asked to write about similarities of two different ways of determining the value of g. One of them is using the slope of the line, and one of them is using the average. Each method used the same L and T values.
September 29, 2011

physics
A rocket is fired straight up and accelerates upward at 24 m/s2 for 12 seconds. The rocket then runs out of fuel and coasts. Ignore any air resistance effects and use -9.8 m/s2 for the local acceleration due to gravity. a) What is the rocket’s maximum altitude? b) How ...
September 28, 2011

Physics 8B
A 280 electric motor is 90% efficient, meaning that 90% of the energy supplied to it ends up as mechanical work. If the motor lifts a 210 weight at 3.5 , how much current does it draw? Express your answer using two significant figures. I= ? Amps
September 18, 2011

physics 8b
A piece of wire with mass per unit length 88 g/m runs horizontally at right angles to a horizontal magnetic field. A 6.5A current in the wire results in its being suspended against gravity. What is the magnetic field strength? Express your answer using two significant figures...
September 16, 2011

Sociology
Q. Jane is thirteen and a middle school student. At her age the most important agent of socialization in her life is likely to be the: a)community b)peer group c)media d)school i think its b. please help me
September 16, 2011

Networking
help
September 13, 2011

Physics
A subway train is designed with a maximum acceleration of ±0.637 m/s2 , which allows for both passenger safety and comfort. (a) If subway stations are 8.6 km apart, what is the maximum velocity that can be obtained between stations? (b) How long does it take to travel ...
September 12, 2011

Physics
A Styrofoam ball of radius 60 cm falls with a terminal velocity of 8.65 m/s. What is the mass of the ball?
September 12, 2011

College Physics
A batted baseball is hit with a velocity of 47.3 m/s, starting from an initial height of 8 m. Find how high the ball travels in two cases: (a) a ball hit directly upward and (b) a ball hit at an angle of 70° with respect to the horizontal Also find how long the ball stays ...
September 12, 2011

College Physics
A batted baseball is hit with a velocity of 47.3 m/s, starting from an initial height of 8 m. Find how high the ball travels in two cases: (a) a ball hit directly upward and (b) a ball hit at an angle of 70° with respect to the horizontal. Also find how long the ball stays...
September 12, 2011

College Physics
Consider a rock thrown off a bridge of height 78.5 m at an angle è = 25° with respect to the horizontal as shown in Figure P4.20. The initial speed of the rock is 15.6 m/s. Find the following quantities: (a) the maximum height reached by the rock (b) the time it ...
September 12, 2011

Physical Science
A 1000-kg car is moving east at 80 km/h collides head on with a 1500-kg car moving west at 40 km/h, and the two cars stick together. Which way does the wreckage move and with what initial speed?
September 11, 2011

algebra
Y=32 x=8
September 11, 2011

Physical Science
A 40-kg skater moving at 4 m/s overtakes a 60-kg skater moving at 2 m/s in the same direction and collides with her. The two skaters stick together. What is their final speed?
September 11, 2011

Physical Science
A boy throws a 4-kg pumpkin at 8 m/s to a 40-kg girl on roller skates, who catches it. At what speed does the girl then move backward?
September 11, 2011

Physical Science
A force of 10 N is used to lift a 600-g ball from the ground to a height of 1.8 m, when it is let go. What is the speed of the ball when it is let go??
September 11, 2011

Physical Science
What do I put my answers in? So the anwser will be 14*8??
September 11, 2011

Physical Science
An escalator 14 m long is carrying a 70-kg person from one floor to another 8 m higher. The escalator has a speed of 1.0m/s. How much work does the escalator do in carrying the person to the top?
September 11, 2011

functions
what is the domain of f(x)={2x^2 -2,if x < or= 1 {x+1,if x>1?
September 9, 2011

geometry
m<AOC=7x-2, m<DOC=2x+8, m<EOD=27 find the value of X
August 30, 2011

geometry
mÚAOC = 7x - 2, mÚDOC = 2x + 8, mÚEOD = 27 help me find the value of x
August 30, 2011

math
Consider the following list of premises: a ^ :b ! c; :a ! :d; Show that g is a valid conclusion by constructing a step-by-step argument
August 22, 2011

physics
An aluminum rod at 18 degrees Celsius has a length of 2.50 meters. At what possible temperatures will it's length change by 1cm?.
August 2, 2011

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