Saturday

July 4, 2015

July 4, 2015

Total # Posts: 990

**Chemistry**

How fast must a 144 g baseball travel in order to have a de Broglie wavelength that is equal to that of an x-ray photon with = 100. pm?
*November 1, 2010*

**Chemistry**

Calculate the energy difference (E) for the transition from n = 1 to n = 6 energy levels of hydrogen per 1 mol of H atoms. (Report your answer to at least 3 significant figures.)
*November 1, 2010*

**chemistry**

Suppose the ΔGof, ΔHof, and ΔSo are available and valid at 298 K. Which equation(s) could be used to calculate the change in Gibbs Energy if all product and reactant concentrations (pressures) are 1 M (1 atm) and the temperature is 298 K? Choose all that apply...
*October 27, 2010*

**chemistry**

how quickly must a 54.7 g tennis ball travel i order to have a de Broglie wavelength that is equal to a photon of green light?
*October 24, 2010*

**English**

Is this a simile or a metaphor The rain felt like small kisses on Rosemary's face,
*October 21, 2010*

**Chemistry**

When 32.0 mL of 0.560 M H2SO4 is added to 32.0 mL of 1.12 M KOH in a coffee-cup calorimeter at 23.50°C, the temperature rises to 30.17°C. Calculate H of this reaction per mole of H2SO4 and KOH reacted. (Assume that the total volume is the sum of the individual volumes ...
*October 20, 2010*

**Chemistry**

A 30.5 g sample of an alloy at 93.7°C is placed into 50.1 g water at 23.4°C in an insulated coffee cup. The heat capacity of the coffee cup (without the water) is 9.2 J/K. If the final temperature of the system is 31.1°C, what is the specific heat capacity of the ...
*October 20, 2010*

**physics**

The only force acting on a 3.0 kg body as it moves along the positive x axis has an x component Fx = -9x N, where x is in meters. The velocity of the body at x = 2.3 m is 9.7 m/s. (a) What is the velocity of the body at x = 4.4 m? (b) At what positive value of x will the body ...
*October 18, 2010*

**Chemistry**

A 26.5 g sample of ethylene glycol, a car radiator coolant, loses 675 J of heat. What was the initial temperature of ethylene glycol if the final temperature is 32.5°C (c of ethylene glycol = 2.42 J/gK)? Please help me, I don't even know where to begin!!
*October 18, 2010*

**Chemistry**

What is the enthalpy change when 17.0 g of water is cooled from 36.0°C to 6.40°C?
*October 18, 2010*

**Chemistry**

3 M HCl solution was used to generate CO2 from the CaCO3 . What will be the effect on the value reported for the molar volume of CO2 if 6 M HCl was used instead (too high, too low, no difference)? Explain.
*October 16, 2010*

**physics**

Two cars, A and B, are traveling in the same direction, although car A is 174 m behind car B. The speed of A is 25.6 m/s, and the speed of B is 18.6 m/s. How much time does it take for A to catch B?
*October 16, 2010*

**Chemistry**

A mixture of gases collected over water at 14C has a total pressure of 1.198 atm and occupies 72 mL. How many grams of water escaped into the vapor phase?
*October 15, 2010*

**Spanish-SraJMcGin-please check**

Posted by Megan on Wednesday, October 13, 2010 at 5:08pm. I just reposted this from the earlier post- I have two questions about translation. If asked this question, how do I answer it. Cual es tu numero de telefono? I know it is asking my phone number which is 447-7161 but I ...
*October 13, 2010*

**Spanish-SraJMcGin-Please check**

Hola, I know about the accent marks-I use spanish typeit and do my work in there when I have to type it-sorry about not doing it here One question, I can only use the words my teacher taught so far in Spanish and I didn't learn ir a nadar for the second one. Can I just put...
*October 13, 2010*

**Spanish**

No numero de telfono-doesn't that say no number of telephone is .... instead of my phone number is .... For what I like to do on Sat. can I say El sabado me gusta....
*October 13, 2010*

**Spanish**

I have two questions about translation. If asked this question, how do I answer it. Cual es tu numero de telefono? I know it is asking my phone number which is 447-7161 but I don't know how to put it in sentence form. The next question is Que te gusta hacer el sabado? I ...
*October 13, 2010*

**physics**

Suppose the water near the top of Niagara Falls has a horizontal speed of 2.7 m/s just before it cascades over the edge of the falls. At what vertical distance below the edge does the velocity vector of the water point downward at a 72° angle below the horizontal?
*October 13, 2010*

**Computers**

How to do Excel Spreadsheet- Formulas? I have to do an excel spreadsheet for my computer class. Problem is my professor didn't at all explain how to do it. What formulas am I supposed to use! Please Help. The info he gave us are : Cash Sales: 56%, Rec. Last month: 28%, Rec...
*October 13, 2010*

**Algebra-Please help-I'm desperate to understand**

Posted by Megan on Tuesday, October 12, 2010 at 3:44pm. I have a question if someone could help, please explain it. Given b = -1 and h = -1, what is the equation of the graph if the parent function of the radical is y = square root (x) The x should be under a square root sign...
*October 12, 2010*

**Algebra-drwls please check!**

Hi, no I just checked this-all they wanted was what a (-b) qunatity and a negative (h) quantity would do to the parent function- like how it would be written If you had the parent function y = square root of (x)-how a negative b and negative h would affect it
*October 12, 2010*

**Algebra-drwls please check!**

Posted by Megan on Tuesday, October 12, 2010 at 3:44pm. I have a question if someone could help, please explain it. Given b = -1 and h = -1, what is the equation of the graph if the parent function is y = sqrt (x) Answers: a.y = sqrt(x-1) b.y = sqrt (-x+1) c.y = - sqrt (-x-1) ...
*October 12, 2010*

**Algebra drwls please check**

Can you please check my problem Thank you
*October 12, 2010*

**Algebra**

I have a question if someone could help, please explain it. Given b = -1 and h = -1, what is the equation of the graph if the parent function is y = sqrt (x) Answers: a.y = sqrt(x-1) b.y = sqrt (-x+1) c.y = - sqrt (-x-1) d.y = sqrt(-x-1) I think it is "b"
*October 12, 2010*

**Geometry**

the measure of the supplement of an angle is 40 more than two times the measure of the complement of the angle find the measure of the angle
*October 11, 2010*

**AP CHEM **

19. Burning coal and oil in a power plant produces pollutants such as sulfur dioxide, SO2. The sulfur-containing compound can be removed from other waste gases, however, by the following reaction: 2 SO2(g) + 2 CaCO3(s) + O2(g) 2 CaSO4(s) + 2 CO2(g) [Molar masses: 64....
*October 7, 2010*

**Chemistry :(**

Disulfur dichloride, S2Cl2, is used to vulcanize rubber. It can be made by treating molten sulfur with gaseous chlorine: S8(l) + 4 Cl2(g) --> 4 S2Cl2(l) [Molar masses: 256.6 70.91 135.0] Starting with a mixture of 32.0 g of sulfur and 71.0 g of Cl2, which is the limiting ...
*October 7, 2010*

**Chemistry**

Calculate the pH, to one decimal place, of the solution made by mixing 21.0 mL of 0.33 M HNO3 with 121.0 mL of 0.32 M formic acid (HCOOH)
*October 7, 2010*

**Chemistry**

Experiment 10: Which Fuels provide the most heat? There are many possible sources of error in this experiment. List three that you can think of. Would each error have a large effect, a medium effect, or a small effect on the calculated heat content of a fuel? Also indicate ...
*October 7, 2010*

**Chemistry! **

Experiment on Which Fuels Provide the Most Heat? Comparison of the Energy Content of Fuels. Suppose you put 50 mL of water in the can instead of 100 mL and heated it 40 degrees instead of 20 degrees. In what ways, if any, would this affect the results of the experiment? What ...
*October 7, 2010*

**Chemistry**

The arrow goes after the C6H5CH2COOH
*October 4, 2010*

**Chemistry**

OH- + C6H5CH2COOH H2O + C6H5CH2COO- What is the K for the reaction above in terms of Ka's, Kb's, Kw etc.?
*October 4, 2010*

**Chemistry**

H- + C6H5CH2COOH = H2O + C6H5CH2COO- What is the K for the reaction above in terms of Ka's, Kb's, Kw etc.?
*October 4, 2010*

**science**

At -8 degrees celseis what state is bromime in?
*October 2, 2010*

**physics**

What average force is needed to accelerate a 6.00-gram pellet from rest to 110 over a distance of 0.800 along the barrel of a rifle?
*September 24, 2010*

**Science **

3. constant angular velocity When a rigid body is being rotated, every particle within the body will rotate in the same direction, while retaining its original shape. The omega(angular velocity) will remain the same.
*September 20, 2010*

**chemistry**

yes, it really does help. How did you decided that it absorbed heat? I though exothermic reactions released it.
*September 19, 2010*

**chemistry**

I don't understand how you decide what is increasing or decreasing and how you tell.
*September 19, 2010*

**chemistry**

2 NO2(g) N2(g) + 2 O2(g) The ΔH° for the reaction above is -66.4 kJ. The system is initially at equilibrium. What happens if N2 is added to the reaction mixture at constant temperature and volume? The reaction absorbs energy. The reaction releases energy. [NO2] ...
*September 19, 2010*

**Chemistry**

H2(g) + I2(g) 2 HI(g) The forward reaction above is exothermic. At equilibrium, what happens if I2 is removed from the reaction mixture at constant temperature and volume? The reaction absorbs energy. The reaction releases energy. [H2] increases. [H2] decreases. [H2] remains ...
*September 19, 2010*

**Chemistry**

Find the volume in liters of 0.452 M manganese(II) sulfate that contains 54.5 g of solute?
*September 19, 2010*

**college-history**

What parallels, or differences, can you identify between Athenian expansionism in the age of the Peloponnesian War and the contemporary career of the American republic?
*September 18, 2010*

**pre cal**

Use synthetic division to show that x is a solution of the third-degree polynomial equation, and use the result to factor the polynomial completely. List all the real zeros of the function. x^3 - 28x - 48 = 0 Value of x = -4 Please help!!Thank you
*September 17, 2010*

**physics**

If your car decelerates at a rat of 4.5 m/s2 how long will it take for your car to stop?????
*September 14, 2010*

**chemistry**

is INH(CH3)3 an acid, base or neutral?
*September 14, 2010*

**math 5 grade**

which x = 300 a 2x30 x6 b 10x6x20 c15x2x10 d 2x3x15
*September 13, 2010*

**math **

leon rents a video for $5. he returns the video game 3 days late. the late fee is $1 for each day late.simplify the expression 5+3.1 to find out how much it costs leon to rent the video game
*September 10, 2010*

**Chemistry**

If you are making 180.0 mL of 3.00% (m/m) CuSO45 H2O, how many grams of the solute should you use? I can't figure out what to do with the percent.
*September 8, 2010*

**chemistry**

Suppose you are given a list of solutions (all with nonvolatile solutes) and their concentrations. You pick out the one with the lowest freezing point. It should also have (pick all that apply): the lowest boiling point the highest osmotic pressure the lowest solvent vapor ...
*September 8, 2010*

**Spanish**

Why do the stem changing forms for -zer and -cer have special endings??
*September 7, 2010*

**Spanish**

Why do the stem changing forms for -zer and -cer have special endings??
*September 7, 2010*

**Chemistry**

A reastion consumes 5.0g of A and 6.0g of B. How many grams of C and D should be obtained? 1A + 3B -> 2C + 4D MC answers: 23 11 1 10 Not enough information to answer the question
*September 6, 2010*

**Chemistry**

A reastion consumes 5.0g of A and 6.0g of B. How many grams of C and D should be obtained? 1A + 3B -> 2C + 4D MC answers: 23 11 1 10 Not enough information to answer the question
*September 6, 2010*

**English**

I need to find the present progressive teses of the words lie, lay,awake
*August 28, 2010*

**math**

The sum of my ones and tens digit is 10. My tens digit is greater than my ones digit. I am a prime number. What number am I? I think it is 19
*August 24, 2010*

**11th grade Chemistry 1**

If your weight is 120 pounds and your mass is 54 kilograms, how would those values change if you were on the moon? The gravitational force on the moon is 1/6 the gravitational force on Earth.
*August 24, 2010*

**8th grade**

Initial observation- is the beginning of your observation and your observation of the whole subject. Independent Variable- is the variable that you change in an experiment. Dependent Variable- is the variable that changes due to the reaction of the independent variable. Keep ...
*August 24, 2010*

**science**

H.) A farmer planted a field of Bt 123 corn and wants to estimate the yield in terms of bushels per acre. He counts 22 ears in 1/1000 of an acre. He determines that each ear has about 700 kernels on average. He also knows that a bushel contains about 90 000 kernels on average...
*August 8, 2010*

**ART**

*have
*August 5, 2010*

**ART**

I need help with the interior and exterior plan of Chartres. The textbook makes its seem so complicated. I can't answer the question. BTW, I didn't post the entire assignment just the two questions I had trouble with.
*August 5, 2010*

**ART**

1. Pretend that you are entering Chartres cathedral through the central portal. You want to get to the apse. What parts of the plan might you traverse in order to get there? Describe what you will see on the way. Hint: There are six architectural features grouped into three ...
*August 5, 2010*

**chemistry**

A 1 m solution of MgCl2 will cause the decrease in the freezing point of water to be approximately ___ than that caused by a 1 m solution of sucrose a. 3x kleiner/ 3x smaller b. 2x kleiner / 2x smaller c. dieselfde / the same d. 2x groter / 2x greater e. 3x groter / 3x greater...
*August 1, 2010*

**Chemistry**

How many calories of heat are needed to raise 10 g water from 20 to 21 degree celcius
*July 22, 2010*

**english 2**

where can i find critiques for the poems "Sometimes Words are So Close" and "Ironing Their Clothes" by julia alvarez?
*June 27, 2010*

**Human Biology**

For a portion of Junior year next year, we're supposed to build a human skeleton out of anything we can find. So most people build them out of styrofoam or clay. Do you think building a skeleton out of twigs would be creative and/or relatively easy? Someone did a really ...
*June 24, 2010*

**math**

Factor the following. You will earn 5 points for each polynomial that is factored correctly. Please label your individual answers with a - f. a.) 4x2 - 25 b.) 3x2 + 6y c.) x2 - 7x + 10 d.) 2x2 - 9x - 18 e.) 2ax + 6bx + ay + 3by f.) 6x2 + 12x - 48
*June 23, 2010*

**math**

at the veterinarian's office terri learned that her dot weighed 4 times as much as her cat. together the pets weighed 40 lbs. how much did the dog weigh
*June 22, 2010*

**algebra**

We just learned equations & inequalities today and im so confused on how to do it!will someone help me??? -5 + 2 < -2
*May 20, 2010*

**Chemistry**

I NEED TO KNOW ASAP what a Keq is and what the formula of it would be.
*May 17, 2010*

**HEALTH**

TWO LETTER WORD FROM EDCIRLUSEEAM RELATING TO HEALTH CARE WEEK
*May 12, 2010*

**Chemistry**

I really don't know how to approach this problem and I really need help. Using the average molarity of your initial acetic acid solutions, the initial volumes, and the volume of NaOH added to reach the equivalence point, calculate the [C2H3O2-] concentration at the ...
*May 6, 2010*

**Chemistry**

An unknown compound analyzes to be 42.85% C, 7.20% H, and 49.95% N. A 0.915 g sample of the gas occupies 250. mL at 760. mm Hg and 100.°C. Type your answers using the format CH4 for CH4. Enter the elements in the order given. I have calculated the emperical formula to be ...
*May 2, 2010*

**Chemistry**

To what Celsius temperature must 44.5 mL of methane gas at 43.0°C be changed so the volume will be 63.0 mL? Assume the pressure and the amount of gas are held constant. I have already tried T1V1=T2V2
*May 2, 2010*

**Chemistry**

NH3(g) + O2(g) NO2(g) + H2O(g) Consider the above unbalanced equation. What volume of NH3 at 950. mm Hg and 33.5°C is needed to react with 190. mL of O2 at 485 mm Hg and 143°C? =? mL
*May 2, 2010*

**Chemistry**

To what Celsius temperature must 44.5 mL of methane gas at 43.0°C be changed so the volume will be 63.0 mL? Assume the pressure and the amount of gas are held constant.
*May 2, 2010*

**Chemistry**

Which of the following increase the melting point of an ionic compound? decreased charge on the ions increased size of the ions increased charge on the ions decreased size of the ions increased amount of the compound
*April 28, 2010*

**Chemistry**

What effect does lowering the pressure on the surface of water have on the boiling point? It increases the boiling point It decreases the boiling point the boiling point remains the same
*April 28, 2010*

**Chemistry **

As ice melts at standard pressure, its temperature remains at 0°C until it has completely melted. Its potential energy: increases decreases remains the same
*April 28, 2010*

**calculus**

Consider the infinite series of the form: (+/-)3(+/-)1(+/-)(1/3)(+/-)(1/9)(+/-)(1/27)(+/-)...(+/-)(1/3^n)(+/-)... (A) Find x and y from: x(</=)(+/-)3(+/-)1(+/-)(1/3)(+/-)...(</=)y.
*April 24, 2010*

**calculus**

Consider the infinite series of the form: (+/-)3(+/-)1(+/-)(1/3)(+/-)(1/9)(+/-)(1/27)(+/-)...(+/-)(1/3^n)(+/-)... (A) Find x and y from: x(</=)(+/-)3(+/-)1(+/-)(1/3)(+/-)...(</=)y. (B) Can you choose the signs to make the series diverge? (C) Can you choose the signs to ...
*April 22, 2010*

**calculus**

Consider the infinite series of the form: (+/-)3(+/-)1(+/-)(1/3)(+/-)(1/9)(+/-)(1/27)(+/-)...(+/-)(1/3^n)(+/-)... (A) Find x and y from: x(</=)(+/-)3(+/-)1(+/-)(1/3)(+/-)...(</=)y. (B) Can you choose the signs to make the series diverge? (C) Can you choose the signs to ...
*April 22, 2010*

**Calculus**

Consider the infinite series of the form: (+/-)3(+/-)1(+/-)(1/3)(+/-)(1/9)(+/-)(1/27)(+/-)...(+/-)(1/3^n)(+/-)... (A) Find x and y from: x(</=)(+/-)3(+/-)1(+/-)(1/3)(+/-)...(</=)y. (B) Can you choose the signs to make the series diverge? (C) Can you choose the signs to ...
*April 21, 2010*

**12th grade agebra 2**

for the first one, all real roots are 2, -2, and the square root of 2. i'm not sure of the second one. hope this helps.
*April 20, 2010*

**Chemistry**

How do I decide whether something is polar or not?
*April 15, 2010*

**Chemistry**

When the Kelvin temperature of an enclosed gas doubles, the particles of the gas ____. a) strike the walls of the container with less force b) move faster c) decrease in volume d) decrease in average kinetic energy
*April 14, 2010*

**Chemistry**

nevermind, the temperature increase
*April 14, 2010*

**Chemistry**

What happens to the temperature of a gas when it is compressed?
*April 14, 2010*

**math 221**

1. Using Excel, find the z-score that corresponds to the following Confidence Levels: a. 80% b. 85% c. 92% d. 97% 2. Using Excel, find the t-score that corresponds to the following Confidence Levels and Sample Sizes: a. 95% with n = 25 b. 96% with n = 15 c. 97% with n = 21 d. ...
*April 6, 2010*

**chemistry**

For each trial, enter the amount of heat gained by the chemical system of ammonium nitrate, qrxn. The specific heat of water is 4.184 J/goC. Report your answer using 4 digits. The information given is: Trial # Tiwater Tf Masswater #1: 21.2 10.8 24.990 #2: 20.8 9.50 25.000 #3: ...
*April 6, 2010*

**Chemistry**

Which of the following electron configurations represent an excited state? 1s22s22p1 1s22s22p63s2 1s1 1s22s12p63s1 1s12s22p63p3 1s22s22p23d1 1s22s22p64s1
*April 1, 2010*

**math**

your first step is to isolate b. to do that, you minus 17 from both sides. so you'd get 5b = (8-17). (do the work yourself, it's pretty simple). so you have 5b still, and your goal is to isoalte b. so you'd divide 5b by 5. and if you do that, you have to divide the...
*March 31, 2010*

**Statistics for Decision**

2.22/84 3.53/84 4 57/84=0.6785 5.18/84 6.18/21 8. indepent high cal have 18/84 and high fiber have 53/84
*March 27, 2010*

**Statistics for Decision**

Calorie Level Fiber Type High Calorie Low Calorie Totals High Fiber 18 4 22 Medium Fiber 23 6 29 Low Fiber 12 21 33 Totals 53 31 84 1. What is the probability that the cereal would be high calorie? In other words, what is P(high calorie)? 2. What is the probability that the ...
*March 27, 2010*

**Chemistry**

If 20.00mL of a solution that contains oxalate ion requires 10.00mL of 0.020M MnO4- solution in a titration, what was the molarity of the oxalate solution? 5C2O42- + 2MnO4- + 12H+ --> 2Mn2+ + 10CO2 + 8 H2O
*March 23, 2010*

**Chemistry**

How do I find the emperical formula of 16.9% Fe3+ 39.7% C2O42- 43.4% H2O
*March 23, 2010*

**4th Grade Math**

Ms. Ross's class has 24 students.2/3 of her students have brown hair.The rest have blonde hair.How many students have blonde hair?
*March 23, 2010*

**3rd grade math**

Write an expression that equals 468 that includes a combination that adds up to 100
*March 16, 2010*

**chemistry**

How many miles of sodium hydrogen carbonate would be needed to react with 150.0 g of sulferic acid?
*March 10, 2010*

**college chem**

1.43e2
*March 9, 2010*

**Chemistry**

If 15.0 kJ are released when 1.40 g of F2 reacts with an excess of SiH4, complete the thermochemical equation below. SiH4(g) + 2 F2(g) SiF4(g) + 4 HF(g) ÄHrxn = ?kJ
*March 8, 2010*