Saturday
August 30, 2014

# Posts by Kris

Total # Posts: 283

chemistry
How many grams of glycolic acid are needed to react with 30 mL of 0.1 M NaOH?
July 2, 2014

math
Thanks
April 27, 2014

math
is 100 over 1000 10%?
April 27, 2014

Math
Solve: -23m-(-35m)= -48
March 11, 2014

math
Justin is 10 years less than half his father's age. If Justin is 12 years old, how old is his father?
March 5, 2014

Calc Help :(((((
Solve it step by step so I can't do the rest. lim x->-infinity (ax^2+b)/(cx+d) Thank you! Answer th
February 23, 2014

Calc Help :(((((
Solve it step by step so I can't do the rest. lim x->-infinity (ax^2+b)/(cx+d) Thank you!
February 23, 2014

statistics
Use a table of t-values to estimate the P-value for the specified one-mean t-test. Left-tailed test, n=12, t= -3.412. a=p<0.005. b= p>0.005. c= 0.005<p<0.01.
February 21, 2014

Angle of elevation
A rocket fired straight up is tracked by an observer on the ground a mile away. a)Show that when the angle of elevation is theta, the height of the rocket in feet is h=5280tan(theta).
February 6, 2014

Angle of elevation
John stands at 12 feet from the foot of a tree. The angle of elevation to the top of the tree is 60°. What is the height of the tree?
February 5, 2014

health
What physical symptoms often accompany social phobia? A. Difficulty talking B. Trembling C. Nausea D. All of the above
December 26, 2013

Math
What is the number of different squares which can be inscribed in a given equilateral triangle?
December 13, 2013

math
A recipe for cooking a turkey states to allow 15 minutes for each pound of turkey and to add 5 minutes per pound if the turkey is stuffed. Our turkey weights 18 pounds and will be stuffed. It takes half an hour for the turkey to cool. What time should the turkey go in the oven...
December 1, 2013

economics
What is the opportunuity cost if you make 15 a hour but you decide not to work for a 1 hour and go to the movie which cost 10 what is the opportunity cost?
November 2, 2013

chem
A 1L flask is filled with 1.25 g of argon at 25 degrees celcium. A sample of ethane vapor is added to the same flask until the total pressure is 1.45 atm. What is the partial pressure of argon in the flask? Chemistry - DrBob222, Tuesday, October 5, 2010 at 9:00pm mols Ar = 1....
October 24, 2013

Quantum Physics
I bet "Cheaters" don't have answer to this question...
October 12, 2013

Quantum Physics
Yes, I was trying to say it should be the answer, but the question required 0<=thetha<=pi... this doesn't satisfy for any answers mentioned above by me... I feel this question is tricky... can someone find the answer?
October 12, 2013

Quantum Physics
8(d) the answer should be thetha = -2*B*t phi = pi/2 I tried thetha = -2*B*t, 2*pi-2*B*t (although this mayn't be always between 0 and pi), 2*B*t (i know its wrong but i tried)
October 12, 2013

Quantum Physics
8(d) I tried everything... I can't get any value for 0<=thetha<=pi
October 12, 2013

Calculus
(cos πx + sin πy)4 = 54
October 9, 2013

Calculus
(cos πx + sin πy)4 = 54; Implicit Differentation
October 9, 2013

Math
Casper bought some pencils at \$.50 each. He had \$3 left after the purchase. If he wanted to buy the same number of note pads at \$.80 each, he would be short \$1.50. Write a linear equation for the number of pencils he purchased. Then solve it.
September 30, 2013

math
a local summer baseball team plays 20 games each season. so far, they have won 9 games and lost 2. how many more games must they play win this season to win at least 75% of all their games?
September 21, 2013

How many milligram of lysozyme (MW=14,600 g/mol) are needed to make 3 liters of a 10^-6 M solution?
September 16, 2013

Chemistry help needed
How many milligram of lysozyme (MW=14,600 g/mol) are needed to make 3 liters of a 10^-6 M solution?
September 15, 2013

Chemistry
How many milligram of lysozyme (MW=14,600 g/mol) are needed to make 3 liters of a 10^-6 M solution?
September 15, 2013

Chemistry
Thanks!
September 15, 2013

Chemistry
How man moles of sodium phosphate are there in 0.4 liters of 0.1M Na2HPO4 (MW=141.96 g/mol)? 2.) How many millimoles in 200 ml?
September 15, 2013

Physics
I am confused, selenium Se, is on the periodic table, but does it combine with other elements on the periodic table? I want to say no because it is a gas. Is that correct.
August 28, 2013

math - geometry
Austin wants to sketch the graph of a circle represented by the given equation. (x - 4)2 + (y + 7)2 = 64 Using complete sentences, describe the steps used to sketch the circle on a coordinate grid
August 19, 2013

ap chemistry
BaO2(s) + 2 HCl(aq) H2O2(aq) + BaCl2(aq) What amount of hydrogen peroxide should result when 1.00 g of barium peroxide is treated with 15 mL of hydrochloric acid solution containing 0.0330 g of HCl per mL? So confused... >.<
August 1, 2013

CHEMISTRY
Bacterial digestion is an economical method of sewage treatment. 5CO2(g) + 55NH4+(aq) + 76O2(g) right arrow Bacteria C5H7O2N(s) + 54NO2-(aq) + 52H2O(l) + 109H+(aq) bacterial tissue The above reaction is an intermediate step in the conversion of the nitrogen in organic ...
August 1, 2013

chemistry
Nitric acid is produced commercially by the Ostwald process, represented by the following equations. 4 NH3(g) + 5 O2(g) 4 NO(g) + 6 H2O(g) 2 NO(g) + O2(g) 2 NO2(g) 3 NO2(g) + H2O(l) 2 HNO3(aq) + NO(g) What mass in kg of NH3 must be used to produce 4.4 multiplied by 106 kg HNO3...
August 1, 2013

AP CHEMISTRY
Thank you so much!
August 1, 2013

AP CHEMISTRY
Okay, it needed four sig figs. the next part of the question is: How could this result be checked without changing the above procedure? What does this mean?
August 1, 2013

AP CHEMISTRY
i understand where my mistake was. when i went to find the %Cu i did: 100%-8.98%= 91.02 (rounding to three sig figs would give me 91.0) both those answers were wrong on the on the online grader
August 1, 2013

AP CHEMISTRY
I found the mass of ZnCl2 to be 136.29g I started out: .0953/136.3= 6.9e-4 then I did: 6.9e-4 x 65.39= .046 and multiplied that by a hundred
August 1, 2013

AP CHEMISTRY
Commercial brass, an alloy of Zn and Cu, reacts with hydrochloric acid as follows. Zn(s) + 2 HCl(aq) ZnCl2(aq) + H2(g) (Cu does not react with HCl.) When 0.5093 g of a certain brass alloy is reacted with excess HCl, 0.0953 g ZnCl2 is eventually isolated. (a) What is the ...
August 1, 2013

ap chemistry
Thank you very much!
August 1, 2013

ap chemistry
so is the answer 171 g F2? I did: 4.5 mol F2 x (38 g/1mol) =171g
August 1, 2013

ap chemistry
the balanced equation is P4+6F2-->4PF3 so i have: 3.01mol PF3 x (6 molF2/4molPF3)=4.5mol2F2 So then i convert it to grams, correct?
August 1, 2013

ap chemistry
265.66g x (1mol/88) = 3.01 mol PF3 correct?
August 1, 2013

ap chemistry
i got 88 mol. is that right?
August 1, 2013

ap chemistry
Consider the following unbalanced reaction. P4(s) + F2(g) PF3(g) How many grams of F2 are needed to produce 212 g of PF3 if the reaction has a 79.8% yield? I did 212/.798=265.66 grams do I convert that to moles next?
August 1, 2013

chemistry
Consider the following unbalanced reaction. P4(s) + F2(g) PF3(g) How many grams of F2 are needed to produce 212 g of PF3 if the reaction has a 79.8% yield?
August 1, 2013

chemistry
What mass in kg of NH3 must be used to produce 4.4 multiplied by 106 kg HNO3 by the Ostwald process, assuming 100% yield in each reaction?
August 1, 2013

chemistry
What mass in kg of NH3 must be used to produce 4.4 multiplied by 106 kg HNO3 by the Ostwald process, assuming 100% yield in each reaction?
August 1, 2013

chemistry
You have a chemical sealed in a glass container filled with air. The glass container has a mass of 200.0 grams and the chemical has a mass of 800 grams. The total mass of the set-up is 1000 grams. The chemical is ignited by means of a magnifying glass focusing sunlight onto ...
August 1, 2013

math
Q1: If K=In a -In b +In c -t/bc,show that K=(ac/b)e^(-t/bc). Q2:Express log(8)5 in terms of m ,where m=lg 2 Q3:Given that log (4)3 =a and log(4)5 =b ,express log(75)16 in terms of a and/or b . really dont know how to do these qns..please help ! thanks a lot
July 18, 2013

math
express y=0.1(1000)^x in the form lg y =mx+c ,where m and c are constants ,and x is a function of x . Determine the constants m and c and the function x .
July 18, 2013

math
evaluate without using a calculator [log(5)4 x log(2)10 ]/ [log(25)√10]
July 18, 2013

Chemistry
List in increasing order of expected Rf values in a TLC experiment: salicylic acid, toluene, and benzophenone.
July 1, 2013

Chemistry!!!
1.)The silica that makes up the stationary phase in TLC chromatophraphy is more polar than the mobile phase. What then might the relative positions of the analgesics on the developed TLC plate tell you about the polarity of these molecules? Does this match the expectations ...
July 1, 2013

math
Sams shoes makes a profit of 38\$ on every pair of athletic shoes it sells. How many pairs of shoes must Sam sell to earn a profit of 950?
June 30, 2013

chemistry
Zn(s) + 2AgNO3(aq) = 2Ag(s) + Zn(NO3)2 (aq) It would require_____g of zinc to produce 5.40g of silver.
June 12, 2013

english
i need help with my ode poem about mom
May 29, 2013

math
a 5700 year old bone has 10 c14 atoms. how much c 14 did it have originally?
May 28, 2013

math
The quotient of p and 5.
May 28, 2013

chem
Given an aqueous solution in which the [H+] = 2.5EE-7 M, what is the molar hydroxide ion concentration
May 5, 2013

Calculus
A right circular cone has a constant slant height of 12 feet. Find the radius of the base for which the cone has maximum value
May 4, 2013

Math
Can you explain why it is yes... Pls.,
April 23, 2013

Math
On a map John is standing at (11,11). His friend Lucy is standing at (1,11). John took 10 steps to the right. Is he standing with Lucy now?
April 23, 2013

Algebra
2 questions I need some help with please! 1. Find the partial sum S5. an= -2n+16 2.Solve the system by triangularizing the augmented matrix and using bakc substitution. 7x=y-6 3y= -5-2x
April 17, 2013

Algebra
I need some help! Determine whether infinite geometric series has a finite sum. If so, find the limiting value. 112+56+28+....
April 16, 2013

Algebra
I need some help! Determine whether infinite geometric series has a finite sum. If so, find the limiting value. 112+56+28+....
April 16, 2013

Literature
In I Am Nujood, The urban elites Nujood encounters in the courtroom and at the Yemen Times lead very different lives from those of Nujood and the country people of Yemen. How are these “enlightened” people actually disconnected from the rest of their society? For ...
April 16, 2013

Literature
In I Am Nujood, what enables Shada to take up Nujood’s cause so quickly and effectively? How does Shada, whom Nujood calls her “second mother,” open up Nujood’s world? Who else teaches Nujood about what a “real” family can be like?
April 16, 2013

Literature
In I Am Nujood, Nujood says that when her family was driven from Khardji, they lost “a small corner of paradise.” How do the injustices endured by Nujood’s father and brother, Fares, show that life in a patriarchal society can be hard not just for women, but for...
April 16, 2013

Math
I need some help. A biologist finds that the population of a certian type of bacteria double seach half-hour. An initial culture has 60 bacteria. 1. What is the population after 3 hours? 2. How long will it take for the number of bacteria to reach 983,040?
April 9, 2013

Algebra Recursive sequence help
I need some help as I'm totally lost! I need to find the first five terms of each recursive sequence. The n-1 on the problem shows it below the a. 1. A1=3 An=2a n-1- 3 2. C1=64, C2=32 Cn= Cn-2 - Cn-1/2
March 31, 2013

Algebra Multiple Choice help!!
I need help with these! I got B for 1. C for 2. and D for 3. Thanks for the help! 1.) Find the values of a, b, and c that will make the statement true. [5 a -2] [5 102] [3 4 –b] = [-3 -4 3] [2c 5 9] [-2 5 9] a.) 8R1-R2--> =R2 b.) -8R1-R2 -> =R2 c.) –8R1 +R2 -&...
March 28, 2013

Algebra Multiple choice!!! Help
1.) Find the values of a, b, and c that will make the statement true. [5 a -2] [5 102] [3 4 –b] = [-3 -4 3] [2c 5 9] [-2 5 9] a.) 8R1-R2--> =R2 b.) -8R1-R2 -> =R2 c.) –8R1 +R2 -> =R2 d.) 8R1-R2 -> =R2 2.) Solve the system by triangularizing the augmented ...
March 28, 2013

Algebra Multiple choice revised!! HELP
I have a few questions I need help with! Please explain if my answer was not right how you got to it. I got 1.) B 2.) A 3.) C 1. Solve the system by triangularizing the augmented matrix and using back substitution. If the system is linearly dependent, give the solution in ...
March 28, 2013

I have a few questions I need help with! 1. Solve the system by triangularizing the augmented matrix and using back substitution. If the system is linearly dependent, give the solution in terms of a parameter. -3x+y-z=-4 6x-2y+2z=8 -12x+4y-4z=-16 2. Solve the system by ...
March 28, 2013

Algebra Multiple Choice
Hello, This is the last of questions I have for my practice assignment. Again I will put what I got. Thanks for your help. 1.) Solve the system using substitution. Write answer as an ordered pair. 4x+2y=8 -5x-2=y A.) First equation (-2,8) B.) Second equation (-2,8) I put A 2...
March 21, 2013

Algebra-Multiple choice
Hello, I have some practice math I'm working through and I'm unsure about the answer. I will also put what I got. Thanks for the help. 1. Solve using any method and identify the system as consistent, inconsistent, or dependent. -2x+y=8 2x+2y=-8 A.) (-4,0); consistent/...
March 21, 2013

maths
I think that what they mean is to lay out something to count the number, they give you the number 5, find something (beans, legos, something) to act as a counter. Use those counters to count to the number 5, or the number 3, use more counters to count above those numbers. ...
March 10, 2013

GEN CHEM
A solution of CaCl2 is prepared by dissolving 1.004 g of the solid in approximately 30 mL of water. How many moles of CaCl2 does this solution contain?
March 3, 2013

Instead of having an "x" for multiplying, the "*" represents multiplication as well. So 93 times 18. The answer would then be 1,674. Hope I helped!
January 30, 2013

Chemistry
Describe how proteins are manufactured in the ribosomes (include discussion of codons and anti-codons).
December 19, 2012

Chemistry
I understand but I thought maybe someone could explain it.
December 19, 2012

math
If x,y,p,q are points on the circle with radius 6 and xp=yq what is pq? I think the answer is cannot be determined Thanks.
December 3, 2012

CHEMISTRY
WHAT IS THE PH OF 0.50 M HC10? KA OF HC10 IS 3.5X10-8
December 3, 2012

english
The location of prospero's island is never given but what kind of place is it ? Design a simple set to suggest the various locations where the action takes place , so that the scene changes quickly.
November 7, 2012

Math
the difference between 3 times a number and 11 is 10
November 5, 2012

Alegbra
The table shows men's shoe sizes in the United States and the corresponding European shoe sizes. Let y = f(x)represent the function that gives the men's European shoe size in terms of x, the men's U.S. size. Men's U.S. shoe size, Men's European shoe size 8 ...
October 27, 2012

physics
Bonnie and Clyde are sliding 500 bank safe across the floor to their getaway car. The safe slides with a constant speed if Clyde pushes from behind with 385 of force while Bonnie pulls forward on a rope with 300 of force.What is the safe's coefficient of kinetic friction ...
October 20, 2012

physics
Bonnie and Clyde are sliding 500 bank safe across the floor to their getaway car. The safe slides with a constant speed if Clyde pushes from behind with 385 of force while Bonnie pulls forward on a rope with 300 of force.What is the safe's coefficient of kinetic friction ...
October 19, 2012

physics!
how to i find the magnitude of a vector from v1 and v2
September 30, 2012

Physics
A monkey is hanging from a branch located exactly 24 meters along the ground from the hunter. The monkey is 14 meters above the ground. The hunter aims directly at the monkey and fires a water balloon at the monkey just as the monkey releases his grip. The balloon has an ...
September 16, 2012

physics
A speed skater moving across frictionless ice at 9.0 hits a 6.0 -wide patch of rough ice. She slows steadily, then continues on at 6.1 m/s. What is her acceleration on the rough ice?
September 11, 2012

Chemistry
How would you prepare 500.0 of an aqueous solution of glycerol with a vapor pressure of 24.8mm Hg at 26 degree Celsius (vapor pressure of pure water=25.21mm Hg)? assume the density of the solution to be 1.00 g/mL.
September 10, 2012

math
Sally has a total of 100 coins after she plays a game .she plays 10times how many coins does she have
September 3, 2012

chemistry
A sample of gas with a mass of 1.62 g occupies a volume of 941 mL at a pressure of 748 torr and a temperature of 20.0 C. What is the molar mass of the gas?
July 26, 2012

calc
At what rate is the amount of material growing if bacteria in a sample increases to 250 when the sample is observed for 150 minutes?
June 21, 2012

Calc
I have the differential equation dP/dt = 0.5(800-P) and I need to get the population equation P(t). Can someone walk me through the steps? Thanks!
May 6, 2012

math
I'm assuming you are trying to solve for x? Okay, your first step is to get all of the variables on one side. So subtract 63x from both sides and you get 30x^3+3x^2-63x = 0 The next thing would be to look at what you can "pull out" of all three "sets" ...
May 6, 2012

Calculus AB
Oh nevermind, something was just set weird on my calculator that was throwing the graph off. I reset it and it looked like it was supposed to.
May 6, 2012

Calculus AB
I'm trying to find the second derivative of h(x)= x^2 + cos(kx) My answer for h'(x) is 2x - ksin(kx) but I'm not sure if that's right. Then the answer I got for h''(x) was h''(x) = 2 - k^2cos(kx) but I'm pretty sure that's wrong based on...
May 6, 2012

math
ABCD is a parallelogram. If AB is equal to 2x + 1 and CD is equal to x + 13, find x.
April 30, 2012

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