Wednesday

October 1, 2014

October 1, 2014

Total # Posts: 752

**please help me on chem**

Commodity prices of NaCl and urea are about $0.033/lb for NaCl (as rock salt) and about $0.10/lb for urea. Calculate the cost of treating 1000 lb of ice on a surface to produce a solution that melts at -3.9 degrees Celsius with each chemical. I know you use to delta ...
*February 27, 2013*

**chemistry**

I am having trouble on this please help Indicate which of these statements is true? For those that are false,.explain why a) addition reactions always involve compounds with multiple bonds b) all addition reactions produce polymers, but not all polymers are addition polymers c...
*February 27, 2013*

**chemistry**

Pleaseeeee helpppp me
*February 26, 2013*

**chemistry**

Commodity prices of NaCl and urea are about $0.033/lb for NaCl (as rock salt) and about $0.10/lb for urea. Calculate the cost of treating 1000 lb of ice on a surface to produce a solution that melts at -3.9 degrees Celsius with each chemical. I know you use to delta T= mkfi ...
*February 26, 2013*

**Chemistry**

My teacher say I don't have to show any calculation so how do I explain it using the graph I have for both??
*February 26, 2013*

**Chemistry**

So nacl is effective in both cases
*February 26, 2013*

**Chemistry**

Sorry wrong post
*February 26, 2013*

**Chemistry**

I found molality of urea but I am not sure how to do after
*February 26, 2013*

**Chemistry**

I have o.236 g for urea and 0.235g for NaCl. And the question is On a gram basis, which is more effective in depressing the freezing point, urea or NaCl? On a mole basis, which Is more effective? I am confused on what depressing the freezing point me and idk how to explain the...
*February 26, 2013*

**Algebra**

The answer is x=1 :)
*February 21, 2013*

**Science **

I need to calcuted the molarity from this 12.5 g of ethylene glycol antifreeze dissolved in o.100kg of water. Density of solution is 1.0 g/mL I know molarity if mole of solute / L of solution. I am confused on how to find the L of solution. Do I add 12.5 and .100g to get the ...
*February 15, 2013*

**Chemistry**

But that one was density of solution, but this problem is density of water so is that different???
*February 15, 2013*

**chemistry**

what are the fundamental particles in antifreeze
*February 13, 2013*

**English Plz Help**

help
*February 1, 2013*

**college chem**

I am still very confused
*February 1, 2013*

**college chem**

Thank you but I am not sure what you mean by derive it
*February 1, 2013*

**college chem**

A researcher explores the ideal gas equation. He measures the pressure of a system at different temperatures ( keeping the volume and moles of the gas constant) and creates a plot of P versus T. What is the slope of the line that results if the volume is 1.0L when 1.0 mol of ...
*February 1, 2013*

**organic chem**

i. imgur. com/J6VpPrc. png what is the mechanism (electron pushing) of this reaction?
*January 31, 2013*

**science**

how much water can dissolve in 700ml of water at 50 c?
*January 31, 2013*

**calculus**

three bowls are filled to a depth of four units. a paraboloid, z=x^2 +y^2 for 0<z<4, a cone z=(x^2 + y^2)^(1/2) for 0<z<4, and a hyperboloid z=(1+x^2+y^2)^(1/2) for 1<z<5. which bowl holds more water?
*January 29, 2013*

**physics**

A near-sighted person might correct his vision by wearing diverging lenses with focal length f = 60 cm. When wearing his glasses, he looks not at actual objects but at the virtual images of those objects formed by his glasses. Suppose he looks at a 10-cm-long pencil held ...
*January 28, 2013*

**organic chemistry**

you divide that by 2 so it's 1
*January 24, 2013*

**organic chemistry**

there is only 1 degree of unsaturation
*January 24, 2013*

**organic chemistry**

what is this compound, it has a mf of c6h12o i. imgur. com/gCgw0Hi. png
*January 24, 2013*

**physic 108**

A charged nonconducting rod, with a length of 3.83 m and a cross-sectional area of 5.69 cm2, lies along the positive side of an x axis with one end at the origin. The volume charge density ρ is charge per unit volume in coulombs per cubic meter. How many excess electrons ...
*January 21, 2013*

**Design**

New Wave
*January 16, 2013*

**physics**

A 91.0 N grocery cart is pushed 17.1 m along an aisle by a shopper who exerts a constant horizontal force of 42.0 N. The acceleration of gravity is 9.81 m/s2 . If all frictional forces are neglected and the cart starts from rest, what is the grocery cart’s final speed? ...
*January 16, 2013*

**math**

The perimeter of the office bulletin board is 24 ft. The perimeter of the sandbox is 1 1/2 times as long. What is the perimeter of the sandbox?
*December 14, 2012*

**Physics**

A spaceship of mass 2.3×10^6 kg is cruising at a speed of 6.0×10^6 m/s when the antimatter reactor fails, blowing the ship into three pieces. One section, having a mass of 5.2×10^5 kg, is blown straight backward with a speed of 2.0×10^6 m/s. A second ...
*November 26, 2012*

**Physics**

A 1.1 kg block slides along a friction-less surface at 1.4 m/s. A second block, sliding at a faster 4.3 m/s, collides with the first from behind and sticks to it. The final velocity of the combined blocks is 2.6 m/s. What was the mass of the second block?
*November 26, 2012*

**Physics**

A 9.6 kg dog takes a nap in a canoe and wakes up to find the canoe has drifted out onto the lake but now is stationary. He walks along the length of the canoe at 0.53 m/s, relative to the water, and the canoe simultaneously moves in the opposite direction at 0.12 m/s. What is ...
*November 26, 2012*

**Physics**

A 9.6 kg dog takes a nap in a canoe and wakes up to find the canoe has drifted out onto the lake but now is stationary. He walks along the length of the canoe at 0.53 m/s, relative to the water, and the canoe simultaneously moves in the opposite direction at 0.12 m/s. What is ...
*November 26, 2012*

**Math**

5/36
*November 19, 2012*

**Physics **

an object has a charge of -2.0 microcoloumbs, how many electrons must be removed so that the charge becomes +3.0 microcoloumbs? I'm not sure of which formula to use
*November 15, 2012*

**world history**

Why did different regions in Africa develop in different ways between 1000 and 1700?
*November 14, 2012*

**algebra**

six people ate one tenth of a pie and there was two fifth left. How much pie did she start with?
*November 13, 2012*

**chem**

what is the ph of a solution in which 250.0 ml of .200 M HNO3 is added to 280.0 ml of .150 Ba(OH )
*November 13, 2012*

**chem**

what is the ph of a solution in which 250.0 ml of .200 M HNO3 is added to 280.0 ml of .150 Ba(OH )
*November 13, 2012*

**chem**

what is the ph of a solution in which 250.0 ml of .200 M HNO3 is added to 280.0 ml of .150 Ba(OH )
*November 13, 2012*

**chem**

what is the ph of a solution in which 250.0 ml of .200 M HNO3 is added to 280.0 ml of .150 Ba(OH )
*November 13, 2012*

**chem**

what is the ph of a solution in which 250.0 ml of .200 M HNO3 is added to 280.0 ml of .150 Ba(OH )
*November 13, 2012*

**chem**

what is the ph of a solution in which 250.0 ml of .200 M HNO3 is added to 280.0 ml of .150 Ba(OH )
*November 13, 2012*

**PHYSICS!!!**

Water flowing through a garden hose of diameter 2.72 cm fills a 25.0-L bucket in 1.10 min. (a) What is the speed of the water leaving the end of the hose? m/s (b) A nozzle is now attached to the end of the hose. If the nozzle diameter is one-third the diameter of the hose, ...
*November 11, 2012*

**PHYSICS!!!**

A liquid (ñ = 1.65 g/cm3) flows through a horizontal pipe of varying cross section as in the figure below. In the first section, the cross-sectional area is 10.0 cm2, the flow speed is 288 cm/s, and the pressure is 1.20 105 Pa. In the second section, the cross-sectional...
*November 11, 2012*

**PHYSICS!!!**

A hypodermic syringe contains a medicine with the density of water (figure below). The barrel of the syringe has a cross-sectional area of 2.89 10-5 m2. In the absence of a force on the plunger, the pressure everywhere is 1.00 atm. A force of magnitude 2.13 N is exerted on the...
*November 11, 2012*

**PHYSICS!!!**

Water moves through a constricted pipe in steady, ideal flow. At the lower point shown in the figure below, the pressure is 1.70 105 Pa and the pipe radius is 2.80 cm. At the higher point located at y = 2.50 m, the pressure is 1.22 105 Pa and the pipe radius is 1.70 cm. (a) ...
*November 11, 2012*

**PHYSICS!!!**

The Venturi tube shown in the figure below may be used as a fluid flowmeter. Suppose the device is used at a service station to measure the flow rate of gasoline (ñ = 7.00 102 kg/m3) through a hose having an outlet radius of 2.72 cm. The difference in pressure is ...
*November 11, 2012*

**PHYSICS!!!**

A square metal sheet 3.1 cm on a side and of negligible thickness is attached to a balance and inserted into a container of fluid. The contact angle is found to be zero, as shown in Figure (a), and the balance to which the metal sheet is attached reads 0.40 N. A thin veneer of...
*November 11, 2012*

**PHYSICS!!!**

To lift a wire ring of radius 1.95 cm from the surface of a container of blood plasma, a vertical force of 1.79 10-2 N greater than the weight of the ring is required. Calculate the surface tension of blood plasma from this information. Answer in N/m
*November 11, 2012*

**PHYSICS!!!**

A certain fluid has a density of 1045 kg/m3 and is observed to rise to a height of 2.4 cm in a 1.0-mm-diameter tube. The contact angle between the wall and the fluid is zero. Calculate the surface tension of the fluid. Answer in N/m
*November 11, 2012*

**PHYSICS!!!**

A straight horizontal pipe with a diameter of 1.0 cm and a length of 46 m carries oil with a coefficient of viscosity of 0.11 N · s/m2. At the output of the pipe, the flow rate is 8.4 10-5 m3/s and the pressure is 1.0 atmosphere. Find the gauge pressure at the pipe ...
*November 11, 2012*

**PHYSICS!!!**

A thin 1.8-mm coating of glycerine has been placed between two microscope slides of width 1.0 cm and length 4.0 cm. Find the force required to pull one of the microscope slides at a constant speed of 0.35 m/s relative to the other slide. Answer in N
*November 11, 2012*

**PHYSICS!!!**

A thin 1.8-mm coating of glycerine has been placed between two microscope slides of width 1.0 cm and length 4.0 cm. Find the force required to pull one of the microscope slides at a constant speed of 0.35 m/s relative to the other slide. Answer in N
*November 11, 2012*

**PHYSICS!!!**

A pipe carrying 20°C water has a diameter of 3.6 cm. Estimate the maximum flow speed if the flow must be streamline. Answer in cm/s
*November 11, 2012*

**PHYSICS!!!**

Sucrose is allowed to diffuse along a 8.0-cm length of tubing filled with water. The tube is 6.1 cm2 in cross-sectional area. The diffusion coefficient is equal to 5.0 10-10 m2/s, and 8.0 10-14 kg is transported along the tube in 18 s. What is the difference in the ...
*November 11, 2012*

**PHYSICS!!!**

Glycerine in water diffuses along a horizontal column that has a cross-sectional area of 2.0 cm2. The concentration gradient is 3.1 10-2 kg/m4, and the diffusion rate is found to be 5.4 10-15 kg/s. Determine the diffusion coefficient. Answer in m2/s
*November 11, 2012*

**physics!!!**

The viscous force on an oil drop is measured to be 6.0 10-13 N when the drop is falling through air with a speed of 9.0 10-4 m/s. If the radius of the drop is 2.5 10-6 m, what is the viscosity of air? Answer in N x s/m^2
*November 11, 2012*

**Chemistry**

The combustion of how many moles of ethane would be required to heat 838 grams of water from 25.0 to 93.0 degrees C? Assume liquid water is formed during the combustion.
*November 2, 2012*

**Chem**

A 53.31-g sample of water at 88.8 degrees C is added to a sample of water at 23.9 degrees C in a constant- pressure calorimeter. If the final temperature of the combined water is 43.3 degrees C and the heat capacity of the calorimeter is 26.3 J/degrees C, calculate the mass of...
*November 2, 2012*

**math**

grant's change rack contained $8.80 in quarters, dimes, and nickels. There were two more than five times as many nickels as quarters and four less than twice as many dimes as quarters. How many of each kind of coin was there in the change rack? please help
*October 22, 2012*

**math**

The second of three numbers is 1 less than than the first. The third number is 5 less than the second. if the first number is twice as large as the third, find the three numbers. write an equation and find the numbers
*October 10, 2012*

**math**

the greater of two numbers is 1 more than twice the smaller. three times the greater exceeds 5 ties the smaller by 10. find the numbers and write the equation. please help me
*October 10, 2012*

**math**

The second of three numbers is 1 less than than the first. The third number is 5 less than the second. if the first number is twice as large as the third, find the three numbers. write an equation and find the numbers please help me
*October 10, 2012*

**physics**

two masses one on an inclined plane at 30 degrees the other suspended
*September 26, 2012*

**college physics**

Newton's second law states that for every action there is an equal and opposite reaction. Draw a force diagram. It is moving at a constant velocity. Your force diagram for an object moving at a constant velocity is the same as your force diagram for an object at rest, so ...
*September 24, 2012*

**Chemistry**

lh
*September 23, 2012*

**Chem**

Paper thickness varies. Typically, 100 sheets are about a cm thick. Atoms typically vary from 1 to 3 angstroms in radius. (An angstrom is 10-10 m.) Suppose a piece of paper is 0.0073 cm thick. How many atoms span the thickness if the radius of the atom is 1.94 angstroms?
*September 12, 2012*

**geology**

why do planets appear to move with respect to stars?
*September 11, 2012*

**algebra**

Perform the subtraction. (4x/x^2+2x-8)-(x/x^2-16)
*September 9, 2012*

**math-algebra**

Factor the polynomial 64x^3-27
*September 9, 2012*

**geology**

determine the Radiocargon age of the sample from its % Modern value. Fragment of Roman Gladiator leather harness 77% modern ___ radiocarbon age BP ____ correct radiocarboned age
*September 4, 2012*

**geology**

Below are descriptions of samples, with known ages expressed as either AD or BC (also called BCE). Convert these dates to BP dates (using 1950 as "the present.") 1. Wood from Egyptian coffin - from the Ptolemic period based on style. Date: 200 ± 150 years BCE
*September 4, 2012*

**Physics**

Good luck with your AGU entrance exam test this Saturday. :D
*August 28, 2012*

**math**

How many ounces of water could be held in a cylinder that has a radius of 2inches and a height of 7 inches if every cubic inch of volume cantains one-fourth ounce of water?
*August 21, 2012*

**geography**

1. All of the following are among the Pillars of Islam except. A. performing daily prayers. B. memorizing the Koran. C. giving to charity. D. making a Hajj. 2. What was the result of Iran's 1979 revolution? A. The Sunnis defeated the Shiites in their struggle for control ...
*August 16, 2012*

**math**

Give the component form of the resultant vector in the following. u = (10, 5) -3u = ?
*July 21, 2012*

**chemistry**

Thank you very much Dr. Bob for your help. I didn't post the original question, but was working on a similar problem. It probably would have taken me an hour to figure this out without your help. Thanks again!
*July 7, 2012*

**Math help please**

(This homework question was removed due to a copyright claim submitted by k12.com.)
*May 21, 2012*

**Chemistry**

Amino acid solution was made by taking 3.58 g of the dry amino acid and making it up to 1.00L in water. A 25.0 mL sample was taken and titrated with NaOH of concentration of 0.0493M, with the first equivalence point at 18.15 mL and the second equivalence point at 32.05 mL. ...
*May 20, 2012*

**combine functions.. please help.**

Given: f(x)=2x^2-x+1 g(x)=2 sin x h(x)=3^x Determine: a) f(g(x)) b) (h^-1 o f)(x) c) g(f(h(x)))) Please show steps, thank you very much.
*May 17, 2012*

**World Civilizations **

A Hindu society in Southeast Asia that resisted both Buddhism and Islam was
*May 4, 2012*

**5th grade math**

She either scored 196 or 327 points Explaination: Range is difference between greatest and smallest numbers. We know the answer of range that is 129. If we consider 325 as greatest number than we can subtract 129 from 325 and get smallest number - 196. If we consider 198 as ...
*April 19, 2012*

**chemistry**

The rate constant for this first-order reaction is 0.0570 s–1 at 400 °C. A-->Products After how many seconds will 14.0% of the reactant remain?
*March 23, 2012*

**geom/trig**

The base of a right rectanglar prism is 12 cm by 8 cm. The height is 5 cm. Find its surface area.
*March 5, 2012*

**algebra 2**

evaluate f(x) = x^-2/3 + x^-3 for each value of x. f(-8)
*March 5, 2012*

**math**

name two different numbers that are greater than .66 and less than .9
*February 22, 2012*

**calculus**

f(x)= 3x^7 +2x -9 If g(x)= f inverse of x and g(-4)= 1, what is g'(-4)? I know that f inverse is the same as 1/f'(x) but I'm not sure where to go from there.
*February 21, 2012*

**math**

Seven thousand raffle tickets are to be sold at $10 each to benefit a local community group. The prizes, the number of each prize to be given away, and the dollar value of winnings for each prize are as follows: Prize Number to Be Given Away Dollar Value Automobile 2 $21,730 ...
*February 11, 2012*

**math**

Suppose that an automobile parts wholesaler claims that .5 percent of the car batteries in a shipment are defective. A random sample of 200 batteries is taken, and four are found to be defective. (a) Use the Poisson approximation to find the probability that four or more car ...
*February 11, 2012*

**math**

A telephone company's goal is to have no more than 4 monthly line failures on any 100 miles of line. The company currently experiences an average of 5 monthly line failures per 50 miles of line. Let x denote the number of monthly line failures per 100 miles of line. ...
*February 11, 2012*

**math**

A telephone company's goal is to have no more than 4 monthly line failures on any 100 miles of line. The company currently experiences an average of 5 monthly line failures per 50 miles of line. Let x denote the number of monthly line failures per 100 miles of line. ...
*February 11, 2012*

**calculus**

Find the limit. lim h → 0 square root (49 + h) − 7 / h Note: Only 49 +h are under square root.
*February 2, 2012*

**chemistry**

A patient has 0.050 L of blood drawn and this volume of blood has a mass of 55.0 g. What is the density of the blood? Answer with the correct number of sig figs
*January 31, 2012*

**chemistry**

(3.84 x 103 x 0.764) + 1.59 answer with the correct sig figs
*January 31, 2012*

**Chemistry - Naming Compounds**

Name the following compound. Ba3Pb2 I don't really understand since both the elements are metals and usually these bonds occur with a metal and nonmetal or two nonmetals.
*January 30, 2012*

**chemistry**

Chloroquine is used to treat malaria. Studies have shown that an effective dose for children is 3.5 mg per kilogram (3.5 mg/kg) of body weight, every 6 hours. If a child weighs 21 kg, how many milligrams of this drug should be given in a 66 hour period?
*January 30, 2012*

**chemistry**

Which of the following is a situation where an object’s potential energy varies as a result of changes due to its chemical composition? The melting of ice. The burning of wood. A ball rolling down a hill. A parachute slowing a skydiver's fall.
*January 29, 2012*

**chemistry**

Which of the following is an example of a chemical change (change in chemical composition) that involves starting with a liquid and ending up with a gas? Burning gasoline (combustion). Boiling acetone. A pond evaporating. Condensation of steam.
*January 29, 2012*

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