Friday
October 31, 2014

Posts by Val


Total # Posts: 133

College Chemistry
how many liters of ethanol contain 1.5 kg of ethonal?
September 14, 2014

college physics
A block of mass 21.5 kg supported by a vertical massless cable is initially at rest. The block is then pulled upward with a constant acceleration of 3.79 m/s2. what is the tension in the cable? what is the magnitude of the net force acting on the mass? what is the speed of the...
July 1, 2014

college physics
A block of mass 21.5 kg supported by a vertical massless cable is initially at rest. The block is then pulled upward with a constant acceleration of 3.79 m/s2. what is the tension in the cable? what is the magnitude of the net force acting on the mass? what is the speed of the...
June 30, 2014

james madison high school algebra
Can anyone help me with Ashworth high algebra 1 part 2 I really need some help I'm not good with math
May 23, 2014

dynamics of catering
It's sometimes permissible to eat _____ with your fingers. A.fried clams B.soft boiled eggs C.hot dogs D.asparagus
March 17, 2014

Math
Do you need to regroup to find 73-35 ?
October 29, 2013

math
the sample of selected men have the average weight of 180 lb with the standard deviation of 30 lb. For a 0.95 degree of confidence find confidence interval for the mean of the whole population, assuming the normal weight distribution and the following conditions: 40 men selected
August 13, 2013

children who require special treatment
I.Q
August 6, 2013

math
How many feet will it take a car traveling at 120 mph to stop?
March 23, 2013

science
property of muscle in which the strength of its contraction can vary from weak to strong
January 31, 2013

science
I am doing the crossword puzzle and I need name nerve fiber control over muscle or gland effector activity
January 31, 2013

science
nerve fiber control over muscle or gland effector activity
January 31, 2013

biology
property of muscle in which the strength of its contraction can vary from weak to strong
January 31, 2013

biology
nerve fiber control over muscle or gland effector activity
January 31, 2013

chem
What is the pH of a 0.22 M solution of HClO4?
December 6, 2012

math
In January 2010, the Burj Khalifa Tower officially became the tallest building in the world. This tower has a curtain wall (the exterior skin of the building) that is approximately 133,500 square yards. Convert this to square feet.
December 5, 2012

math
In January 2010, the Burj Khalifa Tower officially became the tallest building in the world. This tower has a curtain wall (the exterior skin of the building) that is approximately 133,500 square yards. Convert this to square feet.
December 5, 2012

math
Currently, the Toyota Corolla is the best selling car in the world. Suppose that during a test drive of two Corollas, one car travels 224 miles in the same time that the second car travels 175 miles. If the speed of the first car is 14 miles per hour faster than the speed of ...
December 5, 2012

math
Currently, the Toyota Corolla is the best selling car in the world. Suppose that during a test drive of two Corollas, one car travels 224 miles in the same time that the second car travels 175 miles. If the speed of the first car is 14 miles per hour faster than the speed of ...
December 4, 2012

math
A pilot can fly an MD-11 2160 miles with the wind in the same time she can fly 1920 miles against the wind. If the speed of the wind is 30 mph, find the speed of the plane in still air.( Source: Air Transport Association of America)
December 4, 2012

math
Currently, the Toyota Corolla is the best selling car in the world. Suppose that during a test drive of two Corollas, one car travels 224 miles in the same time that the second car travels 175 miles. If the speed of the firstvcar is 14 miles per hour faster than the speed of ...
December 4, 2012

math
Thank you!
December 4, 2012

math
what is the dross product of c/28=49/16
November 30, 2012

math
2*6=4, 4*1=7 8*3=1 find value of 5*5
August 20, 2012

Statisics
The state lottery claims that its grand prize is $1 million. The lucky winner will receive $50,000 upon presentation of the winning ticket plus $50,000 at the end of each year for the next 19 years. Why isn't this really a million-dollar prize? What would it actually be ...
July 19, 2012

Statisics
The state lottery claims that its grand prize is $1 million. The lucky winner will receive $50,000 upon presentation of the winning ticket plus $50,000 at the end of each year for the next 19 years. Why isn't this really a million-dollar prize? What would it actually be ...
July 18, 2012

Statistics
The state lottery claims that its grand prize is $1 million. The lucky winner will receive $50,000 upon presentation of the winning ticket plus $50,000 at the end of each year for the next 19 years. Why isn't this really a million-dollar prize? What would it actually be ...
July 15, 2012

Enviromental Anthro.
1. How do Fairhead and Leach explain the forest-savanna mosaic in West Africa? a) villagers planted trees and told stories about them b) corporations began logging and mining in the region c) the state prohibited slash and burn farming and created a national park d) Western ...
May 7, 2012

Enviromental Anthro.
What effects do herding in East Africa and ranching in North America have on those two environments?
May 7, 2012

trig
cos x/1+sin x + 1+sin x/ cos x= 2sec x
March 12, 2012

bilology
peroxidase cannot be used to break down chemicals such as starch. why?
January 30, 2012

chemistry
how many grams of potassium chlorate must be used to produce 30.0g of oxygen?
January 28, 2012

chemistry
how many grams of potassium chlorate must be used to produce 30.0g of oxygen?
January 28, 2012

calculus
give an example of a function that has: a) only one point of discontinuity b) exactly two ponts of discontinuity c) an infinite number of discontinuity give an example of a function that is: a) continuous at every point b) discontinous at every point i am confused on how to ...
September 25, 2011

health
You have been hired as an administrator in an ambulatory care setting. What factors would you expect to encounter and how would you deal with them?
September 3, 2011

trig
A tower is supported by a guy wire from the top of the tower to the ground 16 ft from its base. The wire makes an angle of 62 with the ground. The length of the wire is a. 30.09 ft b. 18.12 ft c. 28.41 ft d. 34.08 ft
August 12, 2011

statistics
For each of the following samples that were given an experimental treatment, test whether these samples represent populations that are different from the general population: (a) a sample of 10 with a mean of 44, (b) a sample of 1 with a mean of 48. The general population of ...
June 19, 2011

math
What is the greatest and least possible product you can make using the digits 1,3,5,6 and 7 in the multiplication problem below? Use each digit only once,
February 24, 2011

social studies
discribe the ancient Egypt civilasation
January 17, 2011

physical science
change 85 kilograms to grams change 45 meters to centimeters change 70 nanometers to meters
November 20, 2010

Physical science
Acceleration is F/S A=F/M this is: direct inverse not sure both direct &inverse
November 20, 2010

Physical science
determine the velocity of a toy jeep if it has a distance of 80 meters and a time of 8 seconds?
November 20, 2010

Physical Science
force of a toy jeep if the mass=50kg & is traveling at 4m/s& the radius is 50 centimeters.
November 20, 2010

6th Grade English
Hello, I am looking at the subject of no-count nouns. Which says that it does not have a singular or a plural form. The school book gives Paper for an example. But since you can say "papers" which is plural. How can paper be a non-count noun?
October 3, 2010

physics
A stone thrown off a bridge 20 m above a river has an initial velocity of 12 m/s at an angle of 450 above the horizontal. a. What is the range of the stone? b. At what velocity does the stone strike the water? (magnitude and direction)
September 26, 2010

6th Grade Math
How can you find an unknown factor in a multiplication problem? Is the answer: divide the two numbers that you have?
September 2, 2010

math 116
I am taking this course over again for the second time and it is easy for students that have been out of school for a while
May 22, 2010

math
Justin had 44 dollars before spending n dollars on jeans. How much money remains
May 16, 2010

algebra
help me understand how to solve this problem x+4y=17
May 12, 2010

Biology
A mutation has occurred in one chromosome of a spermatogonium. This mutation will show up in how many of the gametes produced from this cell? Choices: A. None B. Two C. All Four D. Cannot be determined I believe it is 2....If the mutation occurs in the spermatogonium it is ...
May 9, 2010

Chemistry
Could someone walk me through this problem? 6CO2 + 6H2O --> C6H12O6 + 6O2 partial pressure of CO2 is .26Torr, temp is 25 celsius, calculate volume of air to prouduce 10g glucose I keep getting confused with stoichiometry....my thinking: convert 10 g glucose to moles (which ...
April 24, 2010

Chemistry
Having some confusion with this question....I have the answers, just not able to reach them. A flask of volume 5L is evacuated and 43.8 g of solid N2O4 is introduced at 77K. The sample is then warmed to 298K during which the N2O4 vaporizes and some dissociates to form brown ...
April 24, 2010

4th grade math
this is copied correctly. the teacher wanted to keep it simple
April 19, 2010

4th grade math
if a rug's perimeter is 17cm and the area is 13cm, what are the reasurments for the length and width?
April 19, 2010

Chemistry
X(g) + 2 Y(g) + 2 Z(g) -->3 M(g) + 2 N(g) I've already found the orders for the following to be: X is 2nd, Y is 1st, Z is 0 and overall of course is 3. But I am confused about the below question. I initially guess that No it doens't occur in one step..but the ...
April 1, 2010

Chemistry
The hydrolysis of sucrose (C12H22O11) produces fructose and glucose (each C6H12O6). Two mechanisms are proposed: I) Step 1: C12H22O11 --> C6H12O6 + C6H10O5 (slow) Step 2: C6H10O5 + H2O--> C6H12O6 (fast) II) C12H22O11 + H2O--> C6H12O6 + C6H12O6 Would these mechanisms ...
April 1, 2010

chemistry
ooh nevermind i made a silly error...i have the answer now :)
March 31, 2010

chemistry
For the first-order reaction A => 3 B + C, when [ A]0 = 0.014 mol·L-1, the concentration of B increases to 0.017 mol·L-1 in 2.7 min. (a) What is the rate constant for the reaction expressed as the rate of loss of A? I found this to be .1923, which I know is ...
March 31, 2010

Chemistry
2A-->B+C given that the initial concentration of A is .022M and that at 69 s, the concentration of B increases to .0095M, what is the rate constant? i know I need to find the new concentration of A at 69s, but I am having trouble with findthing this. I thought it might be ...
March 31, 2010

Chemistry
use t= (1/ [ A]) - (1/ [A ]o) over k
March 31, 2010

Chemistry
i tried multiplying 7/8 and 8/9 by .69 each to find the respective initial concentrations of A to then use for the half life equation t=1/ k*[ A ]
March 31, 2010

Chemistry
The half-life for the second-order reaction of a substance A is 55.8 s when concentration of initial A = 0.69 M. Calculate the time needed for the concentration of A to decrease to the following values. (a) 1/8 of its original value (b) 1/9 of its original value
March 31, 2010

Chemistry
Oops, forgot to post the question. 2A-->B+C given that the initial concentration of A is .022M and that at 69 s, the concentration of B increases to .0095M, what is the rate constant?
March 31, 2010

Chemistry
I need to find the rate constant. I know that it takes 2A to make B, but I am mixed up on how to figure out how to find hte concentration of A at 69s
March 31, 2010

Chemistry
When 442 mg of NO2 is confined to a 150. mL reaction vessel and heated to 300°C, it decomposes by a second-order process. In the rate law for the decomposition of NO2, k = 0.54 1/(M·s). A) what is the initial reaction rate? B) what is the reaction rate if the mass ...
March 31, 2010

Chemistry
How much time is required to electroplate 6.530 µg of chromium from a potassium dichromate solution, by using a current of 118 mA? I thought the ratio of e- to moles chromium would be 6/2 but I guess that is wrong? I am using t= nF/A I already made the proper conversions...
March 29, 2010

Chemistry
Determine the unknown quantity in the following cell at 298.15 K. Pt(s) | H2(g, 1.0 bar)| H+(pH = ?) || Cl -(aq, 1.0 mol·L-1) |AgCl(s), Ag(s), ΔE = +0.36 V. (DrBob) I still wasn't able to figure out the other one--I posted again after that one, but I know there...
March 29, 2010

Chemistry
Pt(s) | H2(g, 2.0 bar) | H+ (pH = 3.0) || Cl -(aq, 0.85 mol·L-1)) | Hg2Cl2(s) | Hg(l) I need to calculate the voltage for the cell. I have used 1E-3 M for my concentration of H+ given the pH=3 . I don't know how to incorporate the 2.0 bar into the nernst equation. I...
March 29, 2010

Chemistry
where does the .0592/2 come from? I've been calculating my RT/nF to be .025693/2 ....this is all so confusing...
March 29, 2010

Chemistry
Yes that's what I used to to try to find the voltage. But my answer is still coming out to be -.1833 which is incorrect
March 29, 2010

Chemistry
Pt(s) | H2(g, 2.0 bar) | H+ (pH = 3.0) || Cl -(aq, 0.85 mol·L-1)) | Hg2Cl2(s) | Hg(l) I need to calculate the voltage of the cell. I have a pretty good idea of how to use the Nernst equation for this, but am unsure if I am calculating the concentration of H+ correctly. ...
March 29, 2010

Chemistry
Nevermind, I made a silly mistake in my calculations...I figured it out :)
March 29, 2010

Chemistry
Pt | Fe2+ (6.4010-5 M), Fe3+ (0.0460 M) || Sn4+ (2.7010-4 M),Sn2+ (0.0750 M) | Pt i need to calculate the voltage of the cell. I know to use E=emf- (RT/nF)lnQ .... I think my problem is with setting up Q. I'm confused on what goes on top and what goes on bottom for the ...
March 29, 2010

Chemistry
Given the elementary reaction: 2 NOBr==>2 NO + Br2 k = 0.80 Which variables obtained for this reaction will produce a straight line? log[NOBr] vs. t [NOBr] vs. t [NOBr]2 vs. t 1/[NOBr] vs. t instinctively i would choose B, but I am not sure what my prof is getting at with ...
March 28, 2010

Chemistry
Gallium65, a radioactive isotope of gallium, decays by first order-kinetics. The half-life of this isotope is 15.2 min. How long would it take for 7/8 of a sample of this isotope to decay? 15.2 min 30.4 min 45.6 min 48.0 min I'm not sure how to do this. I initially tried ...
March 28, 2010

Problem Posting
I literally spent about 15 minutes retyping and rewording things....oh well
March 28, 2010

Problem Posting
trying to post a question, but it says I'm not allowed to post internet addresses--but I'm not. any ideas on this?
March 28, 2010

Chemistry --Need Help!!
Thanks :)
March 24, 2010

Chemistry --Need Help!!
Ive posted twice, but no one's answered yet...I could really use any kind of guidance--particularly for the 1st question :) 1)) The following two half-cells are paired up in a voltaic cell. How will lowering the pH affect the ƒ´E of the overall cell? ClO3-(aq...
March 24, 2010

chemistry
1)) The following two half-cells are paired up in a voltaic cell. How will lowering the pH affect the E of the overall cell? ClO3-(aq) + H2O(l) + 2e- ==> ClO2-(aq) + 2OH-(aq) Eo= 0.35 V I2(S) + 2e-==> 2I-(aq) Eo = 0.54 V A)dE will increase B)dE will decrease C)...
March 23, 2010

Chemistry
1)) The following two half-cells are paired up in a voltaic cell. How will lowering the pH affect the E of the overall cell? ClO3-(aq) + H2O(l) + 2e- ==> ClO2-(aq) + 2OH-(aq) Eo= 0.35 V I2(S) + 2e-==> 2I-(aq) Eo = 0.54 V A)dE will increase B)dE will decrease C)dE...
March 23, 2010

Chemistry
H1+(aq) + Fe(s) ==> H2(g) + Fe2+(aq) I am trying to balance this equation...but I am not sure how to balance the H's. I have the half rxns as e- + H+(aq) ==> H2(g) Fe(s) ==> Fe2+(aq) + 2e- I multiplied the reduc. rxn (top) by 2 so I could get rid of the electrons...
March 22, 2010

Chemistry
For the following electrochemical cell, what is the correct, balanced reaction? Cu(s) | Cu2+(aq) || Ag+(aq) | Ag(s) A. Cu(s) + Cu2+(aq) → Ag+(aq) + Ag(s) B. Cu(s) + Ag+(aq) → Cu2+(aq) + Ag(s) C. Cu(s) + 2 Ag+(aq) → Cu2+(aq) + 2 Ag(s) D. Cu2+(aq) + Ag(s) &#...
March 21, 2010

Chemistry
Use the data in this table to calculate the solubility of each sparingly soluble substance in its respective solution. (a) silver bromide in 0.066 M NaBr(aq) mol · L-1 I know how to do this one, found it to be 1.167E-11 which is correct. (b) nickel(II) hydroxide in 0....
March 19, 2010

Chemistry
Use the data in this table to calculate the solubility of each sparingly soluble substance in its respective solution. (a) silver bromide in 0.066 M NaBr(aq) mol · L-1 I know how to do this one, found it to be 1.167E-11 which is correct. (b) nickel(II) hydroxide in 0....
March 19, 2010

Chemistry
Suppose that two hydroxides, MOH and M'(OH)2, both have Ksp = 1.0 10-12 and that initially both cations are present in a solution at concentrations of 0.0036 mol · L-1. Which hydroxide precipitates first? I know MOH ppt's first...but am not sure how to approach ...
March 19, 2010

Chemistry
I am confused about where I am going wrong here... Suppose that 1.331 g of impure barium hydroxide is dissolved in enough water to produce 250. mL of solution and that 35.0 mL of this solution is titrated to the stoichiometric point with 17.6 mL of 0.0935 M HCl(aq). What ...
March 13, 2010

Chemistry
HA + OH- ---> H2O + A- .05 .03 0 0 "P"ut in -.03 -.03 +.03 +.03 "U"se up .02 0 .03 .03 "G"et Out It didn't line up well the first time. It makes sense to me...just a little tedious. If you have never seen this, what way have you taught ...
March 12, 2010

Chemistry
that simple and I've been working on this stuff for 5 hours! Thanks DrBob...I really wish my professor was able to break things down so clearly. Nice lady but she has a way of making me more and more confused... as for a PUG chart..maybe that's her own thing? It's ...
March 12, 2010

Chemistry
oops so nevermind I realized i made a mistake when calculating the molar mass. I found it to be 46 g/mol but I am still unsure how to find hte pKA value. Thanks!
March 12, 2010

Chemistry
Suppose that 0.483 g of an unknown monoprotic weak acid, HA, is dissolved in water. Titration of the solution with 0.250 M NaOH(aq) required 42.0 mL to reach the stoichiometric point. After the addition of 21.0 mL, the pH of the solution was found to be 3.75. (a) What is the ...
March 12, 2010

Chemistry
I have another similar problem. I have calculated everything given (Correctly), but I can't seem to get the right pH for the stoichiometric point (I keep getting 7.16) Question: Suppose that 50.0 mL of 0.25 M CH3NH2(aq) is titrated with 0.35 M HCl(aq). Refer to table 1 and...
March 12, 2010

Chemistry
Nevermind I researched it for a few hours and finallly figured it out :)
March 12, 2010

Chemistry
Suppose that 30.0 mL of 0.20 M C6H5COOH(aq) is titrated with 0.30 M KOH(aq). Refer to table 1 and table 2. (a) What is the initial pH of the 0.20 M C6H5COOH(aq)? Using ICE i found to be 2.46 The rest I do not know how to set up or solve... (b) What is the pH after the addition...
March 12, 2010

algebra
y=.09(sq)-x+11.5 need to find y if x=10
March 11, 2010

Chemistry --Help 2! :)
Predict whether Fe(OH)2 will dissolve, precipitate, or do neither after: (a) water is added --> dissolve (b) Fe(OH)2 is added--> neither (c) Solid Fe(NO3)2 is added--> precipitate (d) Solid KNO3 is added---> neither I'm given hte answers...but no explanation. ...
March 9, 2010

Chemistry--help!
Given the equilibrium: HCN(aq) + H2O(l) ←→ H3O+(aq) + CN-(aq) ΔH >0; Ka = 4.0 x10-10 What happens to the concentration of hydrogen cyanide [HCN] when the following stresses are placed on the system at equilibrium? NaCl is added ---> Stays the Same but ...
March 9, 2010

Chemistry
Consider the gas-phase equilibrium A ⇌ B. In a series of experiments, different initial amounts of A and B are mixed together, and the mixture in each case is allowed to come to equilibrium. Which one of these experiments would yield values for the amounts of A and B ...
March 8, 2010

Chemistry
Consider the gas-phase equilibrium A ⇌ B. In a series of experiments, different initial amounts of A and B are mixed together, and the mixture in each case is allowed to come to equilibrium. Which one of these experiments would yield values for the amounts of A and B ...
March 8, 2010

Chemistry
Could someone explain the reasoning for this? 6) Which of the following is a false statement about ALL reactions in equilibrium? a) Increasing temperature shifts the reaction toward the products in an endothermic reaction b) Temperature effects on the equilibrium do not depend...
March 8, 2010

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