Wednesday

October 26, 2016
Total # Posts: 2,329

**Chemistry**

An aqueous solution of (NH4)2SO4 has a pH lower than 7. Explain this observation. Thanks! :)

*January 3, 2013*

**US History**

I have a few questions about World War I that I can't seem to find information about in any textbooks or online: Was Russia forced to act in defense of Serbia to protect access to the warm water of the Black Sea? Did France extend support to Russia in an effort to recover ...

*January 2, 2013*

**Advanced Statistics**

What is Conceptual Framework...?

*January 1, 2013*

**Chemistry**

To 40cm^3 of 1mol AgNO3 is added 20cm^3 of 0.500 AlCl3. What is the molar concentration of the resulting AgNO3 solution. The reaction, if needed, is 3AgNO3 + AlCl3 ==> 3AgCl + Al(NO3)3 I worked out the number of moles present in AgNO3 which is 0.04 mol, and the number of ...

*December 30, 2012*

**Chemistry**

Woops I was mistaken! 0.02/0.25L ... the answer comes 0.08moldm^-3! thanks a million

*December 30, 2012*

**Chemistry**

A volume of 10cm^3 of 2M H2SO4 is placed in a volumetric flas of 250cm^3 and filled to the mark with distilled water. What is the molar conc. of the H2So4 in the flask? After I found how many moles there are in 10cm^3, which is 0.02 mol, what is my next step, as because the ...

*December 30, 2012*

**Chemistry**

A mixture containing 0.5 mol of H2 (g) and 0.5 mol of I2 (g) was introduced into a 10L container at a temperature of 448 C. At this temperature the equilibrium constant Kp is 50. i. What is the total pressure in the container before the reaction starts and at equilibrium. ii. ...

*December 26, 2012*

**Chemistry**

A mixture containing 0.5 mol of H2 (g) and 0.5 mol of I2 (g) was introduced into a 10L container at a temperature of 448 C. At this temperature the equilibrium constant Kp is 50. i. What is the total pressure in the container before the reaction starts and at equilibrium. ii. ...

*December 26, 2012*

**algebra 2**

In short: 2x^2-5x-3 becomes 2x^2-6x+x-3. Split and factorise for: 2x(x-3) 1(x-3) Which becomes: (2x+1)(x-3) x=-1/2 or x=3

*December 19, 2012*

**algebra 2**

Are you wanting it factorised? If so: multiply the constant, in this case '-3' by the co-efficient of x^2, so: (2x-3=6) Take the 2 off the co-efficient and replace the constant, -3, with -6, so you have: x^2 -5x -6 Find products of -6 that also add to make -5. The ...

*December 19, 2012*

**Physics**

what grade is this for?

*December 17, 2012*

**algebra**

The owner of a health food store combined cranberry juice that cost $7.79 per quart with apple juice that cost $7.19 per quart. how many quarts of each were used to make 10 quarts of cranberry juice mixture costing $7.61 per quart

*December 10, 2012*

**algebra**

Melissa drives her car 200 kilometers in 2.5 hours. How far can she drive in 6 hours at the same rate?

*December 6, 2012*

**math**

You have found a summer job manning a lighthouse off the northern coast of Vancouver Island. It is a lonely job and you feel the need for some mental stimulation. In your position, 40 m above sea level, you observe two sailboats in line with the lighthouse. The angles of ...

*December 4, 2012*

**Chemistry**

-678 is electron affinity * 2

*November 29, 2012*

**Stats**

The Ledd Pipe Company has received a large shipment of pipes, and a quality control inspector wishes to estimate the average diameter of these pipes. A random sample of 18 pipes produces an average diameter of 2.56 mm with a standard deviation of 0.05 mm. You may assume that ...

*November 28, 2012*

**Stats**

Many colleges and universities hold a “blood drive” for organizations such as the Red Cross. To help with the planning of an upcoming blood drive, we want to estimate the proportion, p, of students and faculty who would be willing to donate a pint of blood. The Red ...

*November 28, 2012*

**chemistry**

how do i convert Pa to atm?

*November 27, 2012*

**chemistry**

calculate number of dichlorine molecules in a 5.00ml container at 40 degrees Celsius and a pressure of 2.14 x 10^4 Pa.

*November 27, 2012*

**math**

Determine all local and global extrema of the function f(x)=x(x−1)

*November 26, 2012*

**TRIF HELP**

No, but thank for the help

*November 20, 2012*

**TRIG HELP**

find the exact solutions over the interval tanx = 1 all real x

*November 20, 2012*

**Chemistry**

@DrBob222- Temperature does not need to be in Kelvin because it is a ratio, converting to Celsius would give her the same answer.

*November 19, 2012*

**Chemistry**

5.0 dm^3= 5 Liters (P1V1/T1)=(P2V2/T2) P1= .92 atm V1= 5.0 L T1=? P2= (800 mmHg/760 mmHg)= 1.05 atm (There are 760 mmHg in 1 atmosphere) V2= 5.7 L T2= 30 degrees Celsius ((.92 atm)*(5.0 L))/(T1)=((1.05 atm)*(5.7 L))/(30 Degrees) 4.6/T1= .1995 4.16/.1995= T1 T1= 20.8 Degrees ...

*November 19, 2012*

**math**

Suppose e^y=sin(x+cosy) Find dy/dx using implicit differentiation

*November 19, 2012*

**Chemistry**

A gaseous mixture consists of 6.95 g of N2, 4.75 g of O2, and 2.75 g of He. What volume does this mixture occupy at 23Â°C and 1.35 atm pressure?

*November 18, 2012*

**Chemistry**

28.014 g

*November 17, 2012*

**Chemistry**

A 35.0-g iron rod, initially at 25.6°C, is submerged into an unknown mass of water at 67.7°C, in an insulated container. The final temperature of the mixture upon reaching thermal equilibrium is 63.5°C. What is the mass of the water?

*November 17, 2012*

**Science**

How do I balance a combustion equation? (PLEASE TELL ME ANY SHORTCUTS)

*November 16, 2012*

**economics**

The price of a wideget increases by 90%. What effect would we expect this to have on the equilibrium wage rate of workers who make widgets? Would this increase, decrease, or keep the wage rate the same?

*November 16, 2012*

**english**

im reading a book called " The berlin boxing club" and i need to answer some questions for hw. theres one question that i need help with which is what is the background of the author? What prompted him/her to write this book? the authors name is robert sharenow. ...

*November 15, 2012*

**Statistics**

disjoint

*November 15, 2012*

**physics**

A red ball is thrown up off the edge of a building 10 m tall with an initial speed of 4 m/s. A) how long does it take for the red ball to strike the ground below? B) If a black ball is dropped off the edge of the same building, how many seconds after the release of the red ...

*November 14, 2012*

**physics**

Runner A is running at a constant rate of 2.3 m/s when he passes RUmmer B who is stationary. Runner A continues running at a constant pace, and Runner B begins to run 4 seconds after Runner A just passes him. If Runner B is accelerating at a rate of .5 m/s^2, how long will it ...

*November 14, 2012*

**physics**

a nasty little boy tries to drop a water balloon from the top of a 20 m tall building so it lands next to and splashes an innocent woman standing on the ground below. how long does the woman have to get out of the way?

*November 14, 2012*

**physics**

a man drives with an average speed of 25 mph for 20 minutes. he rests at his destination for 1 hour and then returns home with an average speed for this leg of the trip of 15 mph A) what is his average speed for the round trip B) What is his average velocity for the round trip

*November 14, 2012*

**physics**

Water is flowing through a horizontal pipe at a rate 0.2 m3/s. The pipe narrows from a radius of 10 cm to 4 cm. What is the change in pressure?

*November 13, 2012*

**physics **

The pressure in a fire hose is 20 atm. How high can a firefighter spray water from this hose? One atm is about 1×105 Pa. The density of water is 1.0 g/ml, or 103 kg/m3. The acceleration of gravity, g, is 9.8 m/s2.

*November 13, 2012*

**physics charges. please help!**

A charge Q = +4.5 uC is located at the origin and is fixed so that it cannot move. A small object with mass m = 2.0 g and charge q = +8.0 uC is released from rest at point A on the x-axis at x = 2.0 cm. The small object moves without friction along the x-axis under the ...

*November 12, 2012*

**world history**

identify zhongguo

*November 8, 2012*

**Physics electric force, please help!**

A charge of +Q and a charge of +2Q are separated by a distance r. The electric force of +2Q on +Q has a magnitude of F and is directed to the right. Which one of the following statements is correct regarding the electric force of +Q on +2Q? (A)The electric force of +Q on +2Q ...

*November 8, 2012*

**algebra**

6b+14=-7-b can u help me find out what b stands for in this problem.

*November 7, 2012*

**Trigonometric **

Given that sinx = 7 /25 pi/2 <or equal to x <or equal to pi Find the value of cos 2x

*November 6, 2012*

**Calculus**

A car traveling 132 feet per second decelerates at a constant rate to 60 feet per second in three seconds. A. what is the negative acceleration? B. How long after the brakes are first applied will it take to come to a complete stop? C. How far does it travel before coming to a...

*November 5, 2012*

**Chemistry**

1000/(1.6*10^-24) = 6.25*10^26 photons/sec

*November 5, 2012*

**physics**

a vending machine ate another students dollar. the student had enough. he dropped the vending machine off a 20 m cliff. at the same time his buddy at the bottom of the cliff throws a grenade straight up towards the vending machine. the grenade strikes the vending machine after...

*November 4, 2012*

**phyicis**

a vending machine ate another students dollar. the student had enough. he dropped the vending machine off a 20 m cliff. at the same time his buddy at the bottom of the cliff throws a grenade straight up towards the vending machine. the grenade strikes the vending machine after...

*November 4, 2012*

**chemistry**

It would be higher than the true value

*November 2, 2012*

**Chemistry**

Oh ok I thought I had to divide by the molecular weight of CaCO3 to find the moles of CO3. So I take the 0.54g CO3 and divide that by 60.01g which gives me 0.009 mol CO3 in 0.009 mol CaCO3?

*November 2, 2012*

**Chemistry**

I have 0.009 moles of CaCO3 and I needed to find how many moles of CO3 are in the CaCO3. I am just making sure I am doing this correctly. 0.009 mol CaCO3 x 60.01/100.09= 0.54g CO3 0.54g CO3/ 100.09g CaCO3 = 0.005 mol CO3

*November 2, 2012*

**phyicis**

Homer Hickham and his buddies launched model rockets in the late 1950's when the US was trying to get a rocket into space. If homer launches a rocket from rest and its engine delivers a constance acceleration of 8.2 m/s^2 for 5.0seconds after which the fuel is used up by ...

*October 29, 2012*

**phyicis**

After cruising at 75 mph down I-80 for 15 minutes on a roach trip, you hit traffic and travel at 15m/s for 15 minutes for the rest of trip. your average speed is 24.26 m/s. What if you were traveling at each speed for the same distance instead of time? What would your average ...

*October 29, 2012*

**Social studies**

how does geography affect the development of a civilization?

*October 20, 2012*

**Math**

the end point of a line segment is (-3,7) and the midpoint is (1-1) find the other endpoint

*October 18, 2012*

**Physics. please help! due tomorrow!**

Let W1 represent the work required to accelerate an object on a frictionless horizontal surface from rest to a speed of v. if W2 represents the work required to accelerate the same object on the same surface from a speed of v to 2v, then which one of the following is the ...

*October 18, 2012*

**chemistry**

calculate the relativistic mass of 1.81x10^24 photons (3.00 mol) with wavelength of 450 nm.

*October 15, 2012*

**Chemistry**

I know, I don't understand. I don't know violet light or red light either, we haven't learned mass of those.

*October 15, 2012*

**math**

y=(w-5)270 for w

*October 15, 2012*

**physics**

A 5.20 package slides 1.57 down a long ramp that is inclined at 13.0 below the horizontal. The coefficient of kinetic friction between the package and the ramp is = 0.305 Calculate the work done on the package by friction. Calculate the work done on the package by gravity. ...

*October 5, 2012*

**physics**

A 5.20 package slides 1.57 down a long ramp that is inclined at 13.0 below the horizontal. The coefficient of kinetic friction between the package and the ramp is = 0.305 Calculate the work done on the package by friction. Calculate the work done on the package by gravity. ...

*October 4, 2012*

**Precalc**

how do I graph this function? x^2-xy+2x-1=0

*October 4, 2012*

**science**

On Earth, the ratio of the force (newtons) to the mass (kilograms) of an object is always the same

*October 4, 2012*

**definition**

CORRECT!!!! Somehow... i never thought of that word!!! thank u!

*September 29, 2012*

**definition**

what is a word that you don't choose when making a choice?

*September 29, 2012*

**Earth Science**

Does energy flows through the Earth's system by heat?

*September 28, 2012*

**Earth Science**

Can someone five me an example of how carbon cycles through the Earth's system?

*September 28, 2012*

**Math - LCD**

What is the LCD for x^2,x, and x?

*September 27, 2012*

**math **

is it true that you only have to check your solution in a rational equation if the solution is 0?

*September 27, 2012*

**Algebra**

All i know is the answer is 122.2%, i don't know what kind of problem this is or how to solve it haha

*September 24, 2012*

**AP Chemistry**

For the reaction ? Al + ? CuSO4 ↽⇀? Al2(SO4)3+? Cu a maximum of how many moles of Al2(SO4)3 could be formed from 5.95 mol of Al and 1.31 mol of CuSO4? Answer in units of mol.

*September 19, 2012*

**AP Chemistry**

For the reaction ? C6H6 + ? O2 ↽⇀? CO2 + ? H2O a maximum of ? moles of CO2 could be formed from 9 mol of C6H6 and 2.81 mol of O2. Answer in units of mol

*September 19, 2012*

**AP Chemistry**

So is it 1655.84?

*September 19, 2012*

**AP Chemistry**

What volume of 3.16 M HNO3 is required to prepare 524 mL of a 0.2 M HNO3 solution? Answer in units of mL.

*September 19, 2012*

**AP Chemistry**

How many grams of sucrose (C12H22O11) must be dissolved in 60 g water to make a solution in which the mole fraction of sucrose is 0.4? Answer in units of g.

*September 19, 2012*

**physics**

A ping pong ball is rolling across a table top at 22 m/s. If it is 71 m away from the edge, how much acceleration does a person blowing on it need to apply to stop it from falling if they blow for 8.7 seconds?

*September 17, 2012*

**physics**

A ping pong ball is rolling across a table top at 22 m/s. If it is 71 m away from the edge, how much acceleration does a person blowing on it need to apply to stop it from falling if they blow for 8.7 seconds?

*September 17, 2012*

**physics**

202.8

*September 17, 2012*

**Math**

What is the smallest number with digits to the thousandths place that will round to 34.6?

*September 17, 2012*

**Stats**

Suppose X & Y are two independent stocks' returns with: E(X) = E(Y) =15% and V(X) = 144, V(Y) = 256 Problem 1. Buy half X and half Y, so w1 = w2 = 0.5 and Z = (X+Y)/2 Note: The answer says that the variance is 100 but I thought it would be 200. Since I would be adding half...

*September 14, 2012*

**science**

what is the density of liquid in a baloon that weighs 20N on a spring scale if the baloon has a volume of 0.75L what is the liquid density g/ml

*September 13, 2012*

**Physics**

Two 125 N forces pull on a 50 kg mass. One of the forces pulls to the right and the other pulls 90 degrees from the first force. What is the net acceleration of the mass?

*September 12, 2012*

**Chemistry**

oh I'm sorry it's a typo The question is this: Calculate the molality of a 0.410 molar aqueous glucose solution whose density is 1.15 g/mol

*September 12, 2012*

**Chemistry**

Calculate the molality of of a sol'n whose density is 1.15 g/ml

*September 12, 2012*

**Algebra**

48m^6

*September 12, 2012*

**science**

bromine and mercury are the only 2 liquids on the periodic table, could you predict this? why or why not?

*September 10, 2012*

**econ**

Suppose there are 1000 identical firms producing diamonds. Diamond miners receive the wage rate w. Assume that the short-run cost function for each diamond-producing firm is C(q) = wq + q2. a. If w = 10, what is the supply curve of an individual firm? What is the market supply...

*September 5, 2012*

**Math**

I am stuck with this logic problem: Logic – Jack of All Trades Trudy loves learning new things and is always taking some course or other forum the local college’s adult education program. She’s signed up for four upcoming classes – calligraphy, picture ...

*August 29, 2012*

**Math**

I am stuck with this logic problem: Logic – Jack of All Trades Trudy loves learning new things and is always taking some course or other forum the local college’s adult education program. She’s signed up for four upcoming classes – calligraphy, picture ...

*August 28, 2012*

**Labor business**

Why?

*August 13, 2012*

**Labor business**

Should only those who are trained lawyers allowed to be arbitrators for labor disputes?

*August 13, 2012*

**math**

339.97 x 48= 16318.56 16318.56+ 3260= 19578.56

*August 13, 2012*

**Computer**

How can I find information to develop an Excel spreadsheet using conclusions from my research about mulimedia tools that aid classroom instruction?

*June 24, 2012*

**physics **

Two identical diverging lenses are separated by 15 cm. The focal length of each lens is -8.0 cm. An object is located 4.0 cm to the left of the lens that is on the left. Determine the final image distance relative to the lens on the right.

*May 30, 2012*

**geometry**

determine the values of x and y for which ABCD is a parallelogram. AB = 3x + 7, BC = y +8, CD = 5x + 1, DA = 2y - 3

*May 29, 2012*

**geometry**

classify a triangle with side lengths 5, 9 and 12 as acute, right, or obtuse

*May 29, 2012*

**geometry**

ABCD is a trapezoid with median EF and bases AB and CD. AB = 18, EF = 28. Find CD

*May 29, 2012*

**math**

what is the inverse of: f(x) = 2(x – 4)^2 + 5

*May 28, 2012*

**Math**

This is how the question looks on the sheet?

*May 27, 2012*

**Math**

A rabbit population satisfies the logistic equation dy dt = 2x10^-7y(10^6- y); where t is the time measured in months. The population is suddenly reduced to 40% of its steady state size by myxamatosis. If the myxamatosis then has no further effeect, how large is the population...

*May 27, 2012*

**Problem Solving**

A 4oz jar of spice costs 92 cents. What is the unit cost per ounce.

*May 23, 2012*