# Posts by Student

Total # Posts: 866

**Chemistry- Dr.Bob**

What is the final temperature and physical state of water when 250 grams of water at 85 degrees C is added to 80.0 grams of ice at -15 degree C? Is the physical state of water liquid? The explanation from bobpursly was this The sum of heats gained =0 80(cice)(0+15)+80Hf+80cw(...

**Chemistry-Dr.Bob 222**

What is the final temperature and physical state of water when 250 grams of water at 85 degrees C is added to 80.0 grams of ice at -15 degree C? Is the physical state of water liquid? I still don't understand how to do this.

**Chemistry**

What is the final temperature and physical state of water when 250 grams of water at 85 degrees C is added to 80.0 grams of ice at -15 degree C? Is the physical state of water liquid? I don't understand the set up. The setup is like this (answered by bobpursly): The sum of...

**Chemistry**

CH4 (g)+ H2O (g) --->/<---- 3H2 + CO Use Le Chateliers Principle to explain what will happen to the number of moles of hydrogen at equilibrium when a) CO is removed b) Water Vapor is removed c) Methane is added d) CO is added e) Pressure is increased by adding argon gas...

**Chemistry**

CH4 (g)+ H2O (g) --->/<---- 3H2 + CO Use Le Chateliers Principle to explain what will happen to the number of moles of hydrogen at equilibrium when a) CO is removed b) Water Vapor is removed c) Methane is added d) CO is added e) Pressure is increased by adding argon gas...

**Chemistry**

What is the final temperature and physical state of water when 250 grams of water at 85 degrees C is added to 80.0 grams of ice at -15 degree C? Is the physical state of water liquid? I don't understand the set up that I have to set the equation equal to 0 ...

**Chemistry**

I got 1.11 x 10^-6 for K. Here is my work: x= 0.004 -2x= -0.008 (change for CH4) Equilibrium for CH4 is 0.087 - 0.008= 0.079 Change in eq for C2H2 is 0.004 and eq is 0.004 (=x) Change in eq for H2 is 0.012 Eq for H2 is 0.012 K= [C2H2][H2]^3/[CH4]^2 K= (0.004)(0.012)^3/(0.079)^...

**Chemistry**

The reaction of CH4 in 2CH4(g) ---->/<---- C2H2(g) + 3 H2 (g) is carried out at a different temperature with an initial concentration of [CH4]=0.087M. At equilibrium, the concentration of H2 is 0.012 M. Find the equilibrium constant at this temperature.

**Math**

C is incorrect- not 30,000

**Chemistry**

how does one go about finding the Tf of this equation 100Hf+100cw(Tf-0) + 300w(Tf-25) =0 and can you also explain what cw and Hf mean? i have no idea.

**Chemistry**

What is the final temperature and physical state of water when 250 grams of water at 85 degrees C is added to 80.0 grams of ice at -15 degree C? Is Tf= 109 C? Is it in the steam phase?

**Chemistry**

A 1.1% (w/w) solution of cocaine hydrochloride (molar mass 339.81 g/mol) in water. Calculate the molal concentration. Is it 0.0297 mol/kg?

**Math**

Please explain and show your work 2 3 -+- 3 4

**Chemistry-Dr.Bob 222**

1. The rate constant for a second order reaction has units of L mol^-1 s^-1. What are the units of the frequency factor, A, for a second order reaction?

**Chemistry**

Calculate the molal concentration. A 1% (w/w) solution of cocaine hydrochloride ( molar mass 339.81 g/mol) in water.

**Chemistry**

On a clear day at sea level, the partial pressure of N2 in air is 0.78 atm at 25 degres C. Under these conditions, the concentration of N2 in water is 5.3 x 10^-4 M. What is the partial pressure of N2 when the concentration in water is 3.5 x10^-4 M?

**Student**

On a clear day at sea level, the partial pressure of N2 in air is 0.78 atm at 25 degres C. Under these conditions, the concentration of N2 in water is 5.3 x 10^-4 M. What is the partial pressure of N2 when the concentration in water is 3.5 x10^-4 M?

**Economy**

Can anyone compare and contrast N. korea and S. Korea economic provisions on private property ? Then compare to the U.S. Economic provisions on private property ? I'm really confused and I don't know much of the subject. This was a Classwork qtn. Thanks.

**Economics**

4. Deregulation and the Cost of Trucking. Suppose the government initially limits the number of trucking firms that can haul freight. The market for truck freight is served by a single firm that produces five million ton-miles of service per year, where one ton-mile is the ...

**Chemistry**

A solution containing equal masses of glycerol, C3H8O3, and water has a density of 1.10 g/mL. Calculate the molality of glycerol. I got 11.9 m.

**Chemistry**

A first-order reaction has a half-life of 26.4 seconds. How long does it take for the concentration of the reactant in the reaction to fall to one-eighth of its initial value?

**Chemistry**

1. As the intermolecular forces between molecules increase in magnitude, do you expect each of the following to increase, decrease or remain the same? My answers: Viscosity: increase Boiling point: increase Vapor pressure: decrease Surface tension: increase Heat of ...

**Chemistry**

A solution containing equal masses of glycerol, C3H8O3, and water has a density of 1.10 g/mL. Calculate the molality of glycerol. I got 11.9 m.

**Chemistry**

1. As the intermolecular forces between molecules increase in magnitude, do you expect each of the following to increase, decrease or remain the same? My answers: Viscosity: increase Boiling point: increase Vapor pressure: decrease Surface tension: increase Heat of ...

**Chemistry-Dr.Bob**

The solubility of CO2 in water at 25 degrees Celsius and P CO2= 1 atm is 0.034 mol/L. What is its water solubility under normal atmospheric conditions (in air, carbon dioxide is about 380 ppmv assuming that CO2 obeys Henry's Law?

**mATH**

You guys are in CCA? This is cheating and against the rules.

**Math**

The volume of a rectangular prism is 6x^3 -x^2 -2x. Which model could represent the rectangular prism? A. Height: 3x-2 Length: 2x+1 Width: x B. Height: 3x+2 Length: 2x-1 Width: x C. Height: 3x-2 Length: 2x-1 Width: x D. Height: 2x-2 Length: 3x+1 Width: x I don't understand...

**Math, pre-algebra**

The volume of a rectangular prism is 6x^3 -x^2 -2x. Which model could represent the rectangular prism? A. Height: 3x-2 Length: 2x+1 Width: x B. Height: 3x+2 Length: 2x-1 Width: x C. Height: 3x-2 Length: 2x-1 Width: x D. Height: 2x-2 Length: 3x+1 Width: x I don't understand...

**Connexus Help me!!**

Congratulations, Shantee!! When is your baby due? Is it a boy or a girl? Good for you!

**Math**

Our difference is 6. We have a sum of 14. What numbers are we? We know number 10. How did you find 4? Please describe and solve the riddle.Write the number sentence.

**Math**

F(x) = square root of x-6 -5

**Algebra**

Find the perimeter of the triangle whose vertices are the following specified points in the plane (-2,-7) (1,-6) and (-7,7)

**Algebra**

Find the perimeter of the triangle whose certified are the following specified points in the plane (5,-1) (-9,3) and (0,1

**U.S History**

Ms. Sue please help I really need it!!!

**U.S History**

Which of these describes the location of the Gulf of Mexico? (5 points) South of West Florida East of East Florida*** West of New Orleans South of Great Britain 4. © 2012 The Exploration Company What can you infer about what Lewis and Clark saw as they moved west from the...

**U.S History**

Ms. Sue please help!!!!

**U.S History**

Which of these describes the location of the Gulf of Mexico? A. South of West Florida B. East of East Florida C. West of New Orleans D. South of Great Britain I think its A.

**Algebra**

The perimeter of a square must be greater than 40 inches but less than 94 inches. Find the range of possible side lengths yay satisfy these conditions.

**Algebra**

8w less than or equal to 9w - 5 or 1-4w > 25. Enter the solution using interval notation?

**Algebra**

Among all rectangles that have a perimeter of 184, find the dimensions of one whose area is largest. Write your answers as fractions reduced to lowest terms.

**Math**

Find the standard form for the equation for the circle center (-4,7/4) and tangent to the y axis

**Algebra**

Compare the graph of a compound inequality involving and with the graph of a compound inequality involving or.

**Algebra**

What compound inequality represents the phrase "all real numbers that are greater than or equal to 0 and less than 8"

**Algebra**

Write an inequality for Six times a number increased by 38 is no more than the number decreased by 14

**Algebra**

Whats an inequality for negative three sevenths of a number is at least 102.

**Phyical Science**

I already got the answer

**Phyical Science**

Which is more expensive to create wind power or natural gas?

**Inequalities**

Write two different inequalities that you can solve by adding 5 and multiplying by -3.

**Math**

A system of equations is shown below: x + y = 3 2x − y = 6 The x-coordinate of the solution to this system of equations is _____. I'm thinking it could be X=3

**Math**

Steve, what is dr/dt? how did you get 1/8pi?

**Health ( ANSWER ASAP)**

what are the answers?

**Math**

Thx so much

**Math**

hello what is b + 6 1/8= 5 3/4

**Algebra Math**

Thank you!!

**math**

These were the multiple choice answers given to me for this problem which don't seem to make sense because I keep getting $4200 A. $3122.18 B. $4994.50 C. $4440.73 D. $86776.40

**Physics**

If a ball has a weight of 6.8N what is the centripetal force of the string

**Math**

ok thanks again.

**Math**

ok thank u

**Math**

the end without the tip

**Math**

what is the measurement of the end of a crayon in cm

**Math**

thank u

**Math**

what is the size of a crayons top tip in centimeters?

**Math**

hi what is m/3+6=3

**AQ4.1.1 MICROMORPH MODULE**

Consider a small module based on interconnected tandem cells of hydrogenated amorphous and microcrystalline silicon as depicted in the figure below. The Voc of a single tandem cell is 1.35V and the short-circuit density Jsc is 12mA/cm2. b) Voc,module=16.2V, Isc,module=120mA B ...

**CIGS AND CDTE FABRICATION**

During manufacturing of a CIGS device, the metal back contact is deposited first, while in case of the CdTe solar cells, the back contact is deposited in the last processing step. What are the configurations of both cells: a) Both the CI(G)S and CdTe solar cells are made in ...

**Language Art**

I Lost the story to this assingment

**Language Art**

2.)Why does the author of "The Drummer Of Shiloh" say it is a "Solemn Night For a boy just turned fourteen"? A.)The wind is full of whispers B.)The Army is Camped near a church C.)The boy will be his 1st battle soon D.)The boy does not like sleeping in a ...

**Language Art**

thank you its C

**Language Art**

I Lost the story so I cant , can you help me find the answer????

**Language Art**

1.)In "The Drummer Boy Of Shiloh", what does the general call the drummer boy? A.)The BRAINS OF THE ARMY b.)The Heart Of The Army C.)The Backbone of the army D.)The PRIDE OF THE ARMY

**Math**

Will runs 6 laps before Megan joins him at the track. They then run together at the same pace. Represent the relationship between the number of laps Will runs + Megan runs.

**Math**

Simplify -(a + 5)

**Math**

Part 2: Once the tiles were laid, mahogany floor trim was installed around the perimeter of the floor. The trim cost $11.85 per foot. Determine the perimeter of the room and the total cost of the floor trim that was installed

**Math**

Thx Owen

**Math**

your management company was hired to take over the maintenance of the room. last year the old floor tiles were replaced with spanish portico special ceramic tiles. the tiles cost $13.50 per square foot. the owner paid $6534 for the tiles. Determine the area of the room!!

**Math**

Thank u Stephanie! Helps a lot :)

**Math**

How is the area of a square related to its side length?

**Math**

The Eatery Restaurant has 200 tables. On a recent evening, there were reservations for fraction 1/10 of the tables. How many tables were reserved?

**Math**

Thank you, Steve

**Math**

At present, the sum of the ages of a father and his son is 33 years. Determine the smallest number of years until the father's age is 4 times the son's age.

**Math**

Hi what is (z-3^2)? I think it equals (1-9). Is that correct?

**Math**

Thanks Ms. Sue

**Math**

What is (z×6)???

**Math**

I got 120 by multiplying 300 and .6 equals 180 then minus 300 equals 120...im confused isn't this right?

**civics**

John knows many people who feel that small business need more support from the government. They support tax break and other benefits for small business owners. Which of the following best describes the most effective type of action these people could follow? A. attack the ...

**help please**

Is it B?

**civics**

Is it C.?

**civics**

The First Amendment to the Constitution protects freedom of speech and of the press. Which of the following examples best demonstrates the constitutional rights? A. An advertisement contains incorrect information about a company's products. B. A man yells, "Fire!&...

**civics**

A political communication that uses a picture to represent something else is an example of ______. A. bias B. prejudice C. propaganda D. symbolism I think the answer is D.

**civics**

Thank you!

**civics**

Which of the following would be part of the Republican Party Platform? A. creating a new health care system B. banning hand gun use C. reducing the size of government D. raising taxes on the wealthy I think the answer is C.

**civics**

is it b.?

**civics**

gabaloolo one year ago which of the following correctly describes an example of how climate affects the economy of countries in North America? (3 points) a. Countries that have varying climates will often also have unstable economies. b. There are not enough crops to grow in ...

**civics**

It didn't say anything about this topic.

**civics**

Which of the following businesses would prefer a weak U.S. dollar to a strong one? A. A Saudi Arabian company that exports oil to the United States B. An American company that imports clothing from Italy C. A Turkish company that imports microchips from the United States D. A ...

**civics**

Which of the following businesses would prefer a weak U.S. dollar to a strong one? A. A Saudi Arabian company that exports oil to the United States B. An American company that imports clothing from Italy C. A Turkish company that imports microchips from the United States D. A ...

**civics**

I have a couple of more questions I need to check, can you check them for me please?

**civics**

is it B?

**civics**

Which of the following actions is most typical of foreign policy intervention? A. The president creates a new economic plan. B. A task force is asked to investigate a possible free trade violation. C. The Environmental Protection Agency regulates automobile emissions. D. A new...

**Math**

A bag contains tiles with the letters -C-O-M-B-I-N-A-T-I-O-N-S. Lee chooses a tile without looking and doesn't replace it. He chooses a second tile without looking. What is the probability that he will choose the letter O both times? A) 1/132 B) 1/72 C) 1/66 D) 1/23 Is the...