Monday

February 8, 2016
Total # Posts: 202

**Chemistry**

Helium-oxygen mixtures are used by divers to avoid the bends and are used in medicine to treat some respiratory ailments. What percent (by moles) of Helium is present in a helium-oxygen mixture having a density of 0.538 g/L at 25 degrees C and 721 mmHg? Express your answer ...
*October 10, 2010*

**Chemistry**

Helium-oxygen mixtures are used by divers to avoid the bends and are used in medicine to treat some respiratory ailments. What percent (by moles) of helium is present in a helium-oxygen mixture having a density of 0.538 g/L at 25 degrees C and 721mmHg? Express your answer ...
*October 10, 2010*

**Chemistry**

Typically, when a person coughs, he or she first inhales about 2.50 L of air at 1.00atm and 25 degreesC. The epiglottis and the vocal cords then shut, trapping the air in the lungs, where it is warmed to 37 degrees C and compressed to a volume of about 1.70L by the action of ...
*October 10, 2010*

**Chemistry**

Redox titrations are used to determine the amounts of oxidizing and reducing agents in solution. For example, a solution of hydrogen peroxide,H2O2, can be titrated against a solution of potassium permanganate, KMnO4. The following equation represents the reaction: 2KMnO4(aq)+...
*October 3, 2010*

**Chemistry**

A volume of 50.0 mL of aqueous potassium hydroxide was titrated against a standard solution of sulfuric acid. What was the molarity of the KOH solution if 19.2 mL of 1.50 M H2SO4 was needed? The equation is 2KOH(aq) +H2SO4(aq)-» K2SO4(aq)+2H2O(l)
*October 3, 2010*

**physics**

A duck has a mass of 2.3 kg. As the duck paddles, a force of 0.07 N acts on it in a direction due east. In addition, the current of the water exerts a force of 0.26 N in a direction of 48° south of east. When these forces begin to act, the velocity of the duck is 0.15 m/s ...
*September 23, 2010*

**math**

i have 3 pints oil and 12 gallons of gas,each lawn mower uses 0.5 pints of oil and 1.5 gallons of gas. How many days can she mow lawns?
*September 16, 2010*

**chemistry**

Thank you! Now I am having problems with part e.
*July 29, 2010*

**chemistry**

I put in the wrong numbers for the second part.
*July 29, 2010*

**chemistry**

I can't figure out how to get the initial pH. Also, when I tried part B I used 21.0 mL*.100M=XmL*0.130 and it wasn't the correct answer.
*July 29, 2010*

**chemistry**

Consider the titration of 21.0 mL sample of 0.110 M HC2H3O2 with 0.130 M NaOH. what is the initial pH? what is the volume of added base required to reach equivalance point? what is the pH at 5.00 mL of added base? pH at one half o the equivalence point? pH at the equivalence ...
*July 29, 2010*

**chemistry**

Calculate the pH of the solution that results from the mixture. 170 mL of 0.12 M C2H5NH2 with 285.0 mL of 0.22 M C2H5NH3Cl.
*July 28, 2010*

**chemistry**

what is the pH of 0.15 M NaF?
*July 28, 2010*

**chemistry**

If 5.05mL of 0.1000 M NaOH solution is needed to just neutralize excess acid after 20.00 mL of HCl was added to 1.00 g of an antacid, how many moles of acid can the antacid counteract per gram?
*July 27, 2010*

**chemistry**

If 5.00 mL of HCl require 4.03 mL of 0.9581 M NaOH to just consume the HCl, what is the concentration of the HCl?
*July 25, 2010*

**chemistry**

need help with these problems: The concentration of glucose in blood is usually about 0.10% (w/v). If 7.0 L of blood are in an average man, how many grams of glucose are in his blood? To obtain the solute for 118 g of a 19.2% (w/w) solution of sugar we would weigh out ________...
*July 20, 2010*

**chemistry**

need help setting this problem up: The heat of fusion of water is 335 J/g. How much heat would be required to melt 10.4 g of ice?
*July 20, 2010*

**Chemistry**

The following reaction was monitored as a function of time: AB--->A+B A plot of 1/[AB] versus time yields a straight line with slope 5.2×10−2 . If the initial concentration of is 0.240M , and the reaction mixture initially contains no products, what are the ...
*July 18, 2010*

**chemistry**

The following reaction was monitored as a function of time: AB--->A +B A plot of 1/[AB] versus time yields a straight line with slope 5.2 x 10^-2 M*s. What is the value of the rate constant (k) for this reaction at this temperature?
*July 17, 2010*

**ch102**

The rate constant of a reaction at 30 was measured to be 5.7×10^-2. If the frequency factor is 1.2 x10^13 /s what is the activation barrier?
*July 16, 2010*

**CH102**

nevermind! figured it out
*July 16, 2010*

**CH102**

If a temperature increase from 18.0 to 34.0 triples the rate constant for a reaction, what is the value of the activation barrier for the reaction?
*July 16, 2010*

**Chemistry**

i tried that but it says its wrong
*April 16, 2010*

**Chemistry**

An air sample contains 0.038% CO2. If the total pressure is 764 mm Hg , what is the partial pressure of CO2?
*April 16, 2010*

**Physics**

thank you so so so much. the answer is .3626
*March 24, 2010*

**Physics**

A hollow plastic spherical bobber of mass 0.005 kg and volume of 50 cm3 floats on the surface of a lake supporting a submersed fishhook and a bait with a combined mass of 0.01 kg and a combined volume of 2 cm3. The density of water is 0.001 kg/cm3. If a fish grabs the bait, ...
*March 24, 2010*

** ENVIRONMENTAL SCIENCE **

A viewpoint expressed in the video material emphasizes the idea that every type of species has its meaning and purpose, and is important part of biodiversity. Unique characteristics of different species contain the secret of harmony in the world, benefiting from each other by ...
*January 19, 2010*

**Algebra/story problem**

Can someone help me work this problem please? The equation y= -1777x+27,153 can be used to predict the number of gun deaths in the United States x years after 2000, that is x=0 corresponds to 2000, x=2 corresponds to 2002, x=4 corresponds to 2004, and so on. Predict the number...
*January 7, 2010*

**Marketing**

What arguments can you make against the common assumption that marketers only worry about advertising?
*December 1, 2009*

**General Physics**

A 0.40 - kg object connected to light spring with a force constant of 19.6 N/m oscillates on a frictionless horizontal surface. If the spring is released from rest, determine the maximum speed of the object.
*November 12, 2009*

**math**

when y=-sinx and y=sin2x - sinx are added together and graphed, why do the maximum values of two sin functions occur where they do?
*October 13, 2009*

**Chopsticks**

3x^2-8x+1=0
*August 31, 2009*

**literary**

I am writing my father's obituary - he passed away unexpectedly on Monday. He was from a very small town and always quoted verse that ended with "And when I go (return) home, I am a boy again" Walt Whitman. Dylan Thomas. Please. Please. I have a deadline tomorrow...
*June 24, 2009*

**algebra**

Graph the equation using the slope and the y- intercept y= 8/5x+5
*June 7, 2009*

** 7th pre-algebra**

I need help understanding how to slove two step equations. Example -10 - k=-36
*May 11, 2009*

**math**

This is incorrect
*April 9, 2009*

**art -year8-writeacher**

thankyou for finding those websites for me they are a great help. i looked at those myself but i wasn`t sure if they were right. thanks again!
*April 3, 2009*

**art -year8**

i need to design a renaissance outfit for art. please could someone help me find some websites that show some outfits that can help me. thankyou.
*April 3, 2009*

**Orientalism**

What are the three aspects of Orientalism
*March 25, 2009*

**Reiny! Reiny! Reiny!**

1. Oanh walked from her home to the grocery store at 3 mi/h and jogged home at 6 mi/h. Her total round trip was 15 minutes (1/4h). How far from Oanh's home is the grocery store? (use an equation to solve this) Help, I am totally clueless on this.
*February 5, 2009*

**PLEASE HELP ME!**

Rewrite each polynomial as the product of two binomials. 1. y^2 + 6y + 9 2. 25x^2 - 10x + 1 3. 36 - y^2 I don't understand how to do these problems, especially what the direction is telling me to do. Someone help me please?
*January 16, 2009*

**Algerba 1**

Rewrite each polynomial as the product of two binomials. 1. y^2 + 6y + 9 2. 25x^2 - 10x + 1 3. 36 - y^2 I don't understand how to do these problems, especially what the direction is telling me to do. Someone help me please?
*January 16, 2009*

**Chemistry**

Thank you for helping me with this.
*December 16, 2008*

**Chemistry**

We did a flame testing lab today with the following metal ions: Sodium, Na^+1 Barium, Ba ^2+ Calcium, Ca ^2+ Copper, Cu ^2+ Potassium, K ^+1 Strontium, Sr ^2+ Lithium, Li ^+1 The question asks to explain the effect of the nitrate ion solution on the color emission. Please help...
*December 16, 2008*

**algebra**

yes. thank you very much
*December 1, 2008*

**algebra**

how would you go about solving this problem? a x 2b/6 x 4/5a
*December 1, 2008*

**algebra**

so would i do this: 82.1 - 86 = -3.9 now that i have the -3.9 would that be the final answer to the question "what is the deviation from the mean that day?"
*November 9, 2008*

**algebra**

so would i do this: 82.1 - 86 = -3.9 now that i have the -3.9 would that be the final answer to the question "what is the deviation from the mean that day?"
*November 9, 2008*

**algebra**

How would i go about answereing this question? The mean temperature in new york one summer was 86 degrees. if the temperature on july 22 of that summer was 82.1 degrees, what was the deviation from the mean that day?
*November 9, 2008*

**math**

How would i go about answereing this question? The mean temperature in new york one summer was 86 degrees. if the temperature on july 22 of that summer was 82.1 degrees, what was the deviation from the mean that day?
*November 9, 2008*

**Writing**

thanks, do you have any ideas that interest you that would be about 3,000 words
*November 8, 2008*

**Writing**

thank you very much. my main interest was the white house. do you have any topics with why question that i could do for that??
*November 8, 2008*

**Writing**

i have to do a research paper for journalism class. It has to be something that has to do with washington, d.c. but the topic cant be too generalo. it has to be something specific that i will be able to write 1,500 to 3,00 words. Also, the topic has to answer a "WHY"...
*November 8, 2008*

**physics**

A pendulum consists of an object of mass 1.07 kg that hangs at the end of a massless bar, a distance 1.14 m from the pivot point. Calculate the magnitude of the torque due to gravity about the pivot point if the bar makes an angle of 22° with the vertical.
*October 9, 2008*

**physics**

A 4422.0 kg truck is parked on a 10.8° slope. What is the friction force on the truck?
*October 9, 2008*

**physics**

A woman has a mass of 64.2 kg. What is her weight on earth?
*October 9, 2008*

**Algebra**

Solve sytems of equations for 7x-3y=31 and y-5=3x I need to find what x and y equal. thanks!
*April 20, 2008*

**Algebra**

Explicitly explain how to tell an answer is correct when solvingi systems of equations. -thanks so much!
*April 3, 2008*

**math**

find distance from (-4,2) to (5,14)
*March 23, 2008*

**Physical Science**

If you poked 3 holes in a vertical line in a bottle filled with water, which hole will spurt water the furthest? Why? -thanks so much for your help!
*March 17, 2008*

**finance and accounting**

Account Word Problems like this I seem not to get the concept , please give me an exam as how to figure out this problem. 1. The liabilities of Acosta Corporation equal one-third of the total assets. And stockholders equity is $160,000. What is the amount of the liabilities. ...
*March 4, 2008*

**finance and accounting**

Account Word Problems like this I seem not to get the concept , please give me an exam as how to figure out this problem. 1. The liabilities of Acosta Corporation equal one-third of the total assets. And stockholders equity is $160,000. What is the amount of the liabilities. ...
*March 3, 2008*

**Science**

How does the ozone effect the wind patterns
*January 22, 2008*

**US history**

Hi! i am wondering if you can explain amendmant 7 in more depth. Thanks!
*January 19, 2008*

**Algebra**

What is the differance between a discrete graph and a continuous graph? Thanks so much!
*January 16, 2008*

**Pre**

A) List two examples of pairs of numbers that share a common factor. B) List a variable pair with a common factor. C) Why do u think ab+ac is called "simplified form"? I don't really what they are asking me to do... ummmm, anyone help me?
*January 7, 2008*

**Just Wondering**

Whats Christmas anyways? Like, how did it become a true holiday? What is the story behind it?
*December 24, 2007*

**Math**

You were busy working on a problem using 4 big squares, 8 rectangles, and 8 small squares. Your partner accidentally knocked some algebra tiles off the your desk. You now have 1 big square, 3 rectangles, and 5 small squares on your desk. Write and algebraic equation that shows...
*December 10, 2007*

**Pre-Algebra**

You were busy working on a problem using 4 big squares, 8 rectangles, and 8 small squares. Your partner accidentally knocked some algebra tiles off the your desk. You now have 1 big square, 3 rectangles, and 5 small squares on your desk. Write and algebraic equation that shows...
*December 10, 2007*

**Pre-Algebra**

You were busy working on a problem using 4 big squares, 8 rectangles, and 8 small squares. Your partner accidentally knocked some algebra tiles off the your desk. You now have 1 big square, 3 rectangles, and 5 small squares on your desk. Write and algebraic equation that shows...
*December 10, 2007*

**French**

so, how do u really say this quote in french? "You are in love when suddenly reality is in your dreams, and you cannot sleep anymore." help?
*December 4, 2007*

**Pre-Algebra**

What does P-E-M-D-A-S mean? I know they are the orders of operation, but I forgot what each letter stand for??? HELP!
*November 28, 2007*

**Pre-Algebra**

Thank you!
*November 28, 2007*

**Pre-Algebra**

okay so the decimal is 0.001 and I need to convert it to a fraction and a precent? how do I do that??
*November 28, 2007*

**Pre-Algebra please help me!!**

OMG! thank you sooo much! genius! it works by the way!!!
*November 26, 2007*

**Pre-Algebra please help me!!**

X- 0 1 2 3 4 5 6 Y- -7 -4 -1 2 5 8 11 this is a x and y table I need to find out wat the rule is to get y. So the equation would start out like: Y=?????? wat do u need to do with x to get y? and I need help badly! so please!
*November 26, 2007*

**algebra**

(p+3)(p-4)(p-3)(p+4)
*November 25, 2007*

**algebra**

consider three consecutive even intergers, the least of which is x. Write a polnomial representing the product of these three intergers.(p+3)(p-4)(p-3)(p+4)
*November 25, 2007*

**math**

1/4 think money like 25 cents
*November 12, 2007*

**Social Studies**

Name 3 documents and or important people involving the government? For example: as one of the documents, The Articles of Confederation can be one. Can anyone name 2 more at least??? PLZ!
*November 12, 2007*

**Pre-Algebra**

So since 2/3 of Spinner 1 is sedans (The 3rd is a truck), and 1/2 of Spinner 2 is purple (the other half is a green), write a multipilcation problem to describe the probability of spinning a purple sedan. Write a problem to describe the probability of spinning a purple truck. ...
*November 8, 2007*

**Pre-Algebra**

So since 2/3 of Spinner 1 is sedans (The 3rd is a truck), and 1/2 of Spinner 2 is purple (the other half is a green), write a multipilcation problem to describe the probability of spinning a purple sedan. Write a problem to describe the probability of spinning a purple truck. ...
*November 8, 2007*

**math**

dwrs can you show your work? Can figure out who you got the 3?
*October 29, 2007*

**math**

Sorry the question didn't come out right. It was supposed to read. 9k + 6 is < or equal to 39.
*October 29, 2007*

**Math**

drwls can you show your work?
*October 29, 2007*

**Math**

9k+6<39 -
*October 29, 2007*

**Social Studies**

What are some interesting facts about the uniforms in the Revolutionary War?
*October 17, 2007*

**Pre-Algebra**

If negative 20 equals 168, negative 15 equals 153, negative 10 equals 138, negative 5 equals 123, 0 equals 108, 5 equals 93, 10 equals 78, 15 equals 63, 20 equals 48, then what is the rule??? Tables: X: -20 -15 -10 -5 0 5 10 15 20 Y: 168 153 138 123 108 93 78 63 48 How do I ...
*October 8, 2007*

**Pre-Algebra**

I mean like the equaled number is the y and the negative or positive numbers are the x...wat do I do with X to get to y???
*October 8, 2007*

**Pre-Algebra**

If negative 20 equals 168, negative 15 equals 153, negative 10 equals 138, negative 5 equals 123, 0 equals 108, 5 equals 93, 10 equals 78, 15 equals 63, 20 equals 48, then what is the rule??? Also, what is the pattern in the informatio above???
*October 8, 2007*

**Social Studies: The Revolutionary War**

What did the First Continental Congress achieve?
*October 7, 2007*

**Social Studies: The Revolutionary War**

How did the fighting at Lexington and Concord affect the relationship between the colonies and the Great Britain?
*October 7, 2007*

**Science**

What does Endoplasmic Reticulum means or is?
*October 6, 2007*

**Pre-Algebra**

in- 0 1 2 3 4 X out- 1 4 10 0's output is 1 and 1's output is 4, then 3's output is 10....wat is the rule to this??? and wat are the outputs for 2, and 4?
*October 6, 2007*

**Pre-Algebra**

in- 0 1 2 3 4 X out- 1 4 10 0's output is 1 and 1's output is 4, then 3's output is 10....wat is the rule to this??? and wat are the outputs for 2, and 4?
*October 6, 2007*

**Pre-Algebra**

X5 x X4
*September 28, 2007*

**English**

I need help with this question: replace the underlined nouns in this paragraph with personal pronouns.Write the pronouns on the lines below. The nouns have a number right next to them for you to read. Here is the paragraph: Squanto was a Pawtuxet Indian man who came to the aid...
*September 28, 2007*

**math**

The difference of two numbers is 9. The sum of 3 times the greater number and 4 more than the lesser number is 51. What are the two numbers? I do not get this question... I have tried many times, but can not get it.. please help! thank you.
*September 20, 2007*

**Math**

7th grade--how do I determine the slope of a set of stairs? Thanks you find it by measuring thr rise over the run i.e. the vertical distance divided by the horizontal distance. thanks
*May 7, 2007*

**Pre-Calculus**

How would you graph y= x^3 +1? I know the slope for the equation is y'= 3X^2. assign numbers to x and solve for y to get the poins. Then graph. Examples: x=1 then y=2 if x=0 then y=1 if x=2 then y=9
*November 13, 2006*