Friday

July 29, 2016
Total # Posts: 369

**Chemistry**

A buffer consists of 0.16 M KHCO3 and 0.39 M K2CO3. Carbonic acid is a diprotic acid with Ka1 = 4.5 10-7 and Ka2 = 4.7 10-11. (a) Which Ka value is more important to this buffer? Ka1 Ka2 I don't understand this one at all. How do I determine which Ka value is more ...
*March 4, 2013*

**Chemistry**

I have no idea why I was having such a hard time with that one. Thank you so much for your help.
*March 4, 2013*

**Chemistry**

Yeah, I got (a). The answer was 7.53. But when I try to solve (d), I keep getting the wrong answer. I subtracted the moles of NaOH from the acid and added the moles to the base. Then I did Ka = (x*([NaClO]+x))/([HClO - x) and then I found the pH. I got 8.07, but it was wrong.
*March 4, 2013*

**Chemistry**

An industrial chemist studying bleaching and sterilizing prepares several hypochlorite buffers. Find the pH of the following buffers. (a) 0.090 M HClO and 0.090 M NaClO (b) 0.090 M HClO and 0.135 M NaClO (c) 0.135 M HClO and 0.090 M NaClO (d) One liter of the solution in part...
*March 4, 2013*

**Chemistry**

Find the pH of a buffer that consists of 0.82 M methylamin (CH3NH2) and 0.71 M CH3NH3Cl (pKb of methylamine (CH3NH2) = 3.35.) I keep getting 3.41, but it says that it's wrong...
*March 3, 2013*

**Chemistry**

Calculate the pH of 0.215 M carbonic acid (H2CO3). (HINT: do NOT worry about the second H+ in this acid!) How would I solve this?
*March 3, 2013*

**physics**

if the angular speed of earth becomes 17times its present value what will be the 1.effect on a body on the equator of earth? it will be A. Heavier than present value B.lighter than present value C.weightless And also what is the reason? 2.a girl sitting on a swing stands up. ...
*March 1, 2013*

**physics**

if the angular speed of earth becomes 17times its present value what will be the 1.effect on a body on the equator of earth? it will be A. Heavier than present value B.lighter than present value C.weightless And also what is the reason? 2.a girl sitting on a swing stands up. ...
*March 1, 2013*

**Math**

thanks, there was a similar problem instead of 220 men and women it was 275.. i just substituted
*February 28, 2013*

**Data mining**

2. AllElectronics caries 1000 products, P1, … P1000. Consider customers Ada, Bob, and Cathy such that Ada and Bob purchase three products in common, P1, P2, and P3. For the other 997 products, Ada and Bob independently purchase seven of them randomly. Cathy purchases 10 ...
*February 20, 2013*

**science**

i have to prepare a new technology based model for science fair that has been rarely known. Is there any different technology in america or england that is rarely known?
*February 15, 2013*

**MATHS GEOMETRY!!! URGENT PLEASE. **

A triangle has side lengths 10,17 and 21cm. Find the length of the shortest altitude. And please show working out to help me understand.
*February 15, 2013*

**physics**

sound waves travel faster in humidity than in dry air. But as temperature increases the velocity of sound also increases. So sound travels faaster in hot day than in winter. But during winter there is also presence of humidity in fog. Why doesn't sound travel faster in ...
*February 3, 2013*

**Physics**

0.88cm; depth dependence. listen to your prof.
*January 18, 2013*

**physics**

what is the refrevtion of waves? And what are the laws'of refraction? Also about phase change.
*January 13, 2013*

**physics**

1. What are the examples of supersonic waves? 2. What is match cone, match no? 3. Define echo? 4. What is the effect of frequency on the velocity of sound in a gas? 5. Mathematical expression of beats. ''based on wave motion''
*January 13, 2013*

**Interpersonal Communications**

Imagine that you are hosting a group of exchange students next term. You are responsible for welcoming the students to campus and acquainting the students with life on campus socially as well as academically
*December 18, 2012*

**Algebra**

The number is 14 more then the number to the sum of 30
*December 2, 2012*

**maths**

i tried this way but answer not coming..... :/ ans is 0.25
*November 24, 2012*

**maths**

a circular ink-blot grows at a rate of 2 sq cm per second. find the rate at which the radius is increasing after (28/11)seconds.
*November 24, 2012*

**Math**

A 2.5 ton truck stops and a 1300 pound car slams the brakes and skids 26 feet and hits the truck at 40 mph pushing the truck a foots length. how fast was the 1300 pound car traveling?
*November 7, 2012*

**history**

how are longhouses and present day homes alike '
*November 6, 2012*

**mathematics**

A farmer buys a tracter for Rs 120000. he pays Rs 60000 cash and agrees to pay the balance in annual installments of Rs 5000 plus 12% interest on the unpaid amount. what will the tracter cost him?
*November 4, 2012*

**Science**

2. Contrast the metric units of distance, time, and speed. Describe the relationship between them.
*October 23, 2012*

**physics**

A 2100 car starts from rest at the top of a 5.0m long driveway that is sloped at 20 degrees with the horizontal. If an average friction force of 4000N impedes the motion find the speed of the car at the bottom of the driveway.
*October 16, 2012*

**physics**

how can we collect sound energy from outside? then it can be converted into electricity with the help of transducer. Have to prepare a model on this. Please earlier.
*October 9, 2012*

**busines ethics and starting a small business**

I need exam answers to 25 questions that are on the the above college subject exam.
*October 4, 2012*

**chemistry**

density= mass/ volume
*October 1, 2012*

**chemistry**

5H2O stands for the dehydration of copper sulphate.it shows that copper sulphate solution is hydrated.
*October 1, 2012*

**mathematics **

what is the range of the function f(x)=1/root(|x|-x) and its domain.
*September 23, 2012*

**Thinking Mathematically**

solve A Flag Pole Has A Height Of 16 Yards. It Will Be Supported By Three Cables, Each Of Which Is Attached To The Flagpole At A Point 4 Yards Below The Top Of The Pole And Attached To The Ground At A Pole. Find the total number of feet of cable that will be required
*September 23, 2012*

**mathematics **

if [x] denotes the integral part of x, then what is the solution set of the equation [x]^2 -5[x]+6=0
*September 22, 2012*

**mathematics **

what is the domain and range of the function F(x)= 1/1-2cosx
*September 22, 2012*

**mathematics **

what is the domain of the function f(x)= 1/root([x]^2-[x]-6)
*September 22, 2012*

**mathematics**

What is the domain of the functions f(x)= 1/root(x+|x|) f(x)= x|x|
*September 22, 2012*

**math**

Kate is saving to take an SAT Prep course that costs $350 and saved $180 and she adds $17 to her savings each week. How many more weeks must she save to be able to afford the course? Need the answer right now!
*September 21, 2012*

**physics**

what is the graph of potential energy and kinetic energy against distance?
*September 21, 2012*

**mathematics**

what is the square and square root of zero
*September 21, 2012*

**physics**

what is time paradox and time dillation?
*September 20, 2012*

**physics**

list the contact and non contact forces in mathematics. What is the cold welding?
*September 20, 2012*

**mathematics**

how many liters of water will have to be added to 1125 liters of 45% solution of acid so that the resulting mixture will contain more than 25% but less than 30% acid content.
*September 20, 2012*

**mathematics**

in triangle abc if acosA= bcosB then how to prove the triangle is isosceles or right angled
*September 20, 2012*

**mathematics**

what is the domain of the function f(x)=1/root[2x-3]
*September 20, 2012*

**mathematics**

the complex numbers 1,-1,iorta root3 form which type of triangle in graphical form
*September 20, 2012*

**mathematics**

write the number of points of intersection of 2y=1 and y= sinx. -2pi<_x<_2pi
*September 20, 2012*

**mathematics**

what is the maximum value of sinthetacostheta?
*September 20, 2012*

**chemistry**

what is the bond order of n2 positive, n2neagative, n2 2neagative?
*September 20, 2012*

**Math**

how do you find m in the equation: (two fifths) m equals 6 2/5 m = 6
*September 17, 2012*

**fluid power**

assume that the input piston has an area of 4.25 inches squared with a force of 3150 pounds what is the pressure in the system
*September 13, 2012*

**statistics**

4. Suppose you administered an anxiety test to a large sample of people and obtained normally distributed scores with a mean of 45 and standard deviation of 4. Do not use web-calculator to answer the following questions. Instead, you need to use the Z distribution table in ...
*September 3, 2012*

**chemistry**

PF3 SBr2 CH3Br CHCl3 - should have a bond angle of 109.5 as it is tetrahedral but the actual bond angle between the CH bond and CCl bonds will be less than 109.5 and the angle between CCl bonds will be more than 109.5. This is because the Cl atoms have electrons around them ...
*August 23, 2012*

**sciences **

from where does salt come in the sea.
*August 11, 2012*

**home chemistry **

if we grind some sugar and in this ground sugar, we add some salt in it then it will become a mixture of sugar and salt. so how can we separate sugar and salt.
*August 11, 2012*

**physics**

A 20 g bullet moving horizontally with a speed v hits a 2-kg block of wood resting on a table. After hitting the block the bullet is embedded in the block of wood and the block and the bullet moves a distance of 40 cm before it stops. If the coefficient of friction between the...
*July 23, 2012*

**physics**

i have given an assignment by school to prapare a working model of physics. Please give me some tips.
*July 20, 2012*

**sciences**

i want to become amember of young scientist association in my school. But for this i must give an idea of any science project . Please help me
*July 18, 2012*

**physics**

how many RPM are required to attain 1g with a radius of 840 feet
*July 11, 2012*

**maths**

if a bowling green is 1350meters square and the chemical is 0.4 litres a hectare how much do you put on
*June 29, 2012*

**physics**

a stone is dropped from arising balloon at a height of 76m above the ground and reaches the ground in 6 seconds. Caculate the velocity of ballon when the stone was dropped?
*June 26, 2012*

**physics**

a gun is fired from a distance of 1:2 km from a hill. The echo of sound is heard after 7:1seconds at same place. Calculate the velocity of bullet fired.
*June 26, 2012*

**physics**

find the area of parallelogram whose adjacent sides are +3+3 and -3-2+.
*June 26, 2012*

**drawing**

please give me some important tips about decoration of a science chart based on 'tiger in trouble.'
*June 21, 2012*

**chemistry**

please explain clearly. I just didn't understand the question.
*June 21, 2012*

**drawing**

i have to put a topic 'tiger in trouble'. Please help earliar
*June 20, 2012*

**drawing**

please give me some important tips about decoration of a science chart.
*June 20, 2012*

**earth**

thank you very much.
*June 20, 2012*

**earth**

please give me some important tips about a topic 'tiger in trouble'. I have to prepare a chart on this.
*June 20, 2012*

**chinese**

translate these sentences-: 1 i am not free. 2 good bye i'll see you later. 3 hello how are you? 4 don't disturb me, let me study. 5 may you please give me this book.
*June 17, 2012*

**spanish**

please translate these sentences into spanish-: 1.how are you? 2don't disturb me? 3.i want to drink something. 4.oh, i got it. 5. I want to do my work. 6.please be quite.
*June 17, 2012*

**french**

i want to learn this language. Please write some french sentences and also translate them into english. Please earlier, its very urgent.
*June 17, 2012*

**physics**

a gun is fired from a distance of 1.2 km from a hill.the echo of the sound is heard after 7.1 seconds at the same place. Calculate the velocity of sound.
*June 17, 2012*

**non-medical**

a drop of oil of radius 0-20mm spreads on a circular film of diameter 20mm on the water surface. Estimate the size of molecule.
*June 11, 2012*

**non-medical**

a particle with velocity u is moving with uniform accelration a. Distance moved by particle in the nth second is given by s= ut+a)2t-1. What are the dimensions of s?
*June 11, 2012*

**non-medical**

a gun is fired from a distance of 1.2 km from a hill. The echo of sound is heard at same place after 7.1 seconds what is velocity of sound?
*June 11, 2012*

**Physics**

it wouldn't slow the car down at all its redundet there just isn't enough pressure behind the fly to stop the car or to slow it down it would kill the fly and make a speck of guts on the windshield
*June 6, 2012*

**Geometry**

solve A Flag Pole Has A Height Of 16 Yards. It Will Be Supported By Three Cables, Each Of Which Is Attached To The Flagpole At A Point 4 Yards Below The Top Of The Pole And Attached To The Ground At A Pole. Find the total number of feet of cable that will be required
*March 5, 2012*

**Chemistry-Stoichiometry**

A 1.146g mixture of the solid salts NaS)4 and PB(NO3)2 forms an aqueous solution with the precipitation of PbSO4. How would I write the molecular form of the equation for the reaction?
*March 1, 2012*

**math**

18mm 9mm whats the base its a trapazoid
*February 28, 2012*

**math**

9 1/4 miles walked
*February 24, 2012*

**science**

In 91% (by volume) isopropyl alcohol (a large [compared to water], flammable molecule) solution, there are only two substances: the alcohol, and water. So when I poured 50 mL of 91% isopropyl alcohol into a graduated cylinder, how many milliliters were alcohol? How many were ...
*February 6, 2012*

**statistics**

Decide whether the experiment is a binomial, Poisson, or neither based on the information given. Each week a man plays a game in which he has a 21% chance of winning. The random variable is the number of times he wins in 64 weeks.
*February 4, 2012*

**algebra**

There is a process to this and it's why I am asking for help.
*December 20, 2011*

**algebra**

List all possible rational zeros for the polynomial below. Find all real zeros and factor completely. Please show all your work. f(x) = 2x^4 + 19x^3 + 37x^2 - 55x - 75
*December 20, 2011*

**probability**

Find the probability that an insurance company will receive more than one warranty claim per day for at least eight of the next 10 days.
*November 7, 2011*

**statistics**

Anne, Joe and Lynn, in this order, will take turns to draw two cards from a standard deck of 52 cards. Note that each draw of 2 cards is w/o replacement but draws of different turns are with replacement (the preceding two cards will be put back and the deck will be reshuffled...
*November 7, 2011*

**finance**

IBM issued $1,000 30 year bonds. The bonds sold for $936 and pay interest semi-annually. The required rate of return is 7%. wha tis the semiannual interest payment on the bonds?
*October 30, 2011*

**Finance**

Can you show how to solve 1.8667 = (1+r)^5
*October 27, 2011*

**physics**

A mass M can slide with negligible friction inside a tube bent in a circle of radius R = 1.45 m. The tube rotates about its diameter; the mass is in equilibrium at ¦È = 47.3¡ã. Calculate the number of revolutions the hoop makes in 115 s.
*October 7, 2011*

**6th gr,ade math**

there are 5 boys in a class of 20 students, what percent are boys?
*August 22, 2011*

**Government**

Yeah it is B because the president can deploy the armed forces for sixity days and following that congress must approve the deployment of the troops.
*July 19, 2011*

**physics **

A race car is able to accelerate at a rate of 14m/s2. After exiting a turn at a speed of 15m/s, the car enters a straightaway and accelerates to a speed of 96m/s just as it reaches the end of the straightaway and enters the next turn. A)how long did it take the car to ...
*July 18, 2011*

**physics **

a bus is driving through traffic as it makes a number of express stops. the bus drives at a speed of 10 m/s2 for 90 seconds then drives at a speed of 15m/s for 120 seconds before stopping for 30 seconds, then drives at a speed of 5m/s for 60 seconds before stopping for 15 ...
*July 18, 2011*

**Physics **

A 10 kg block is pushed across a rough surface by a 25N force the block moves at a constant velocity when this force is applied. A) determine the magnitude of the friction force acting on the block B) What is the coefficient of friction between the surface and the block
*July 18, 2011*

**Physics **

A spring scale has a spring coefficient of 400 n/m. Determine the mass of an object if it causes the scale's platform to sink .08m.
*July 18, 2011*

**Physics**

A 1200 kg car accelerates to the right at 7m/s2 along a special frictionless track. Determine the magnitude and direction of the force the engine exerts to accelerate the car? A wind blows heavy winds into the car's path.As a result the car's acceleration slows to 4.5m...
*July 18, 2011*

**Physics **

15kg block rests on a rough surface (u=.35) a 100N force to the left is applied to the block. what is the magnitude and direction of the net force acting on the block? How quickly will the block accelerate over the rough surface?
*July 18, 2011*

**Physics **

two forces act concurrently on a 5kg block resting on a smooth horizontal surface a 5N force making a 40degree angle with the surface and a 10n making a 20degree angle with the surface. A) Determine the magnitude and direction of the net force acting on a box.
*July 18, 2011*

**physics**

A man in manhattan is told that his destination is 26 blocks east at 30 degree angle uptown from where he stood on houston street determine how many blocks east and how many blocks uptown from where he stood.
*July 18, 2011*

**physical science**

If the earth had twice its present radius and twice its present mass, what would happen to your weight? Explain. What is the relationship between the radius (R) of orbit of a satellite and its period (T)?
*July 14, 2011*

**physics**

Advertisements for A toy balk once stated that it would rebound to a height greater than the hethe height from which it was dropped. Is this possible?
*July 14, 2011*