Tuesday
October 21, 2014

Posts by Hannah


Total # Posts: 2,889

calc
The price in dollars of a house during a period of mild inflation is described by the formula P(t)=94000 e0.03 t, where t is the number of years after 1990. Answer the following questions: B. In the year 2000 the value will be increasing at a rate of dollars per year. (Round ...
February 22, 2013

chem
for a would be toward reactants?
February 21, 2013

chem
For each of the following equilibria, use Le Chatelier's principle to predict the direction of reaction when the volume is increased. (a) C(s) + H2O(g) CO(g) + H2(g) (b) 2 H2(g) + O2(g) 2 H2O(g) (c) 2 Fe(s) + 3 H2O(g) Fe2O3(s) + 3 H2(g) a i put no change because there are ...
February 21, 2013

chem
then subtract the 4x^2? so .051984-.912x=276x^2 now what?
February 20, 2013

chem
.051984+4x^2 - .912x=280(x^2)
February 20, 2013

chem
what do i do after i get .051984+4x^2 - .912/(x^2)
February 20, 2013

chem
do u have to use teh quadratic to find x?
February 20, 2013

chem
For the reaction I2(g) + Br2(g) 2 IBr(g), Kc = 280. at 150.°C. Suppose that 0.570 mol IBr in a 2.50-L flask is allowed to reach equilibrium at 150.°C. What are the equilibrium concentrations of IBr, I2, and Br2?
February 20, 2013

chem
(a) At 800 K the equilibrium constant for I2(g) 2 I(g) is Kc = 3.1 10-5. If an equilibrium mixture in a 10.0-L vessel contains 3.25 10-2 g of I(g), how many grams of I2 are in the mixture? (b) For 2 SO2(g) + O2(g) 2 SO3(g), Kp = 3.0 104 at 700 K. In a 2.00-L vessel the ...
February 20, 2013

physics
a flowerpot falls from a window ledge far above the street. Some distance down, phil fizyks observes that the pot takes 0.25 seconds to pass her window, which has a height of 2.0m. How far above the top of the window did the pot fall from?
February 20, 2013

physics
a bowling lane is 16.5m long. A young bowler throws a strike and hears the pins striking the floor 4.1 seconds after releasing the ball. How fast was the ball traveling? (The speed of sound in air is 343 m/s)
February 20, 2013

physics
a bowling lane is 16.5m long. A young bowler throws a strike and hears the pins striking the floor 4.1 seconds after releasing the ball. How fast was the ball traveling? (The speed of sound in air is 343 m/s)
February 20, 2013

Maths
Use a2 + b2 = c2 of the right triangle to find the length of the missing side. c=hypotenuse which in this case is 5. 3^2 + b^2 = 5^2 9 + b^2=25 b^2=16 b=4 sin=opposite over hypotenuse which is 4/5 tan=opposite over adjacent which is 4/3 sec=the reciprocal of cosine which is 5/...
February 20, 2013

physics
In a thundercloud there may be an electric charge of 54 C near the top of the cloud and −54 C near the bottom of the cloud. If these charges are separated by about 4 km, what is the magnitude of the electric force between these two sets of charges? The value of the ...
February 19, 2013

chem
that would still be 1.85 with 3 sig figs
February 19, 2013

chem
N2O4 -> 2NO2 I 1.596 1.008 C .252 -.504 E 1.845 .504
February 19, 2013

chem
A flask is charged with 1.596 atm of N2O4(g) and 1.008 atm of NO2(g) at 25°C, and the following equilibrium is achieved. N2O4(g)-> 2 NO2(g) After equilibrium is reached, the partial pressure of NO2 is 0.504 atm. (a) What is the equilibrium partial pressure of N2O4? for ...
February 19, 2013

chemistry
nevermind i got it
February 16, 2013

chemistry
then like teh same for thsi one Assume that Kc = 0.0130 at 520°C for the first reaction above. What is the Kc for the second reaction at the same temperature? 2 HI(g)->H2(g) + I2(g) HI(g)->½ H2(g) + ½ I2(g) why cant you just divide the k by 2?
February 16, 2013

chemistry
Assume that Kc = 0.0360 at 520°C for the first reaction above. What is the Kc for the second reaction at the same temperature? 2 HI(g)-> H2(g) + I2(g) H2(g) + I2(g) -> 2 HI(g) I thought the answer woudl just be negative because all you have to do is switch the ...
February 16, 2013

chemistry
NH4HS(s) <-> NH3(g) + H2S(g) An equilibrium mixture of this reaction at a certain temperature was found to have (NH3)=.268 and (H2S)=.360 What is the value of the equilibrium constant at this temperature?
February 13, 2013

bio
What effect does glucose 6 phosphate have on cellular respiration? I am doing a bio lab using a respirameter (sp?) and am trying to come up with a question to test. I am testing the respiration of germinating seeds and was thinking something along the lines of "How does ...
February 13, 2013

chemistry
NH4HS(s) <-> NH3(g) + H2S(g) An equilibrium mixture of this reaction at a certain temperature was found to have (NH3)=.268 and (H2S)=.360 What is the value of the equilibrium constant at this temperature?
February 13, 2013

Pre-Calculus
Sue is building a triangle out of sticks. The length of the first side is "a" and the second side is of length "b". The length of the third side must be between 8 and 26 units. Find the product of "a" and "b".
February 11, 2013

chem
The activation energy of a certain reaction is 65.7 kJ/mol. How many times faster will the reaction occur at 51°C than at 8°C? State the assumptions you need to make in order to perform this calculation. (Select all that apply.) The collision model and the Arrhenius ...
February 10, 2013

chem
A certain first-order reaction has a rate constant of 2.75 10-2 s−1 at 20.°C. What is the value of k at 50.°C if Ea = 75.5 kJ/mol? i know to use the ln(k1/k2)= (ea/R)((1/T1)-(1/T2)) but how do i know what T2 is when i only have one temp? there is a b part to the ...
February 10, 2013

science
I figured that one out but can smoneoe help me with this one. The activation energy of a certain reaction is 65.7 kJ/mol. How many times faster will the reaction occur at 51°C than at 8°C?
February 9, 2013

science
Calculate the fraction of atoms in a sample of argon gas at 365 K that has an energy of 11.0 kJ or greater.
February 9, 2013

Physics, help!!
How do I get the equation T=2pi(sqrt(m/k)) to the linear equation y=mx+b?
February 4, 2013

chem
torr
February 2, 2013

chem
does the temperature it gives have anything to do with the problem?
February 2, 2013

chem
i just tried that and it is wrong.
February 2, 2013

chem
is k negative because of the s-1? without making it negative i got 15.21 which seemed more reasonable but when i plugged it in it was wrong
February 2, 2013

chem
i got 11873 which seems kinda high..?
February 2, 2013

chem
The decomposition of sulfuryl chloride (SO2Cl2) is a first-order process. The rate constant for the decomposition at 660 K is 4.5 10-2 s-1. (a) If we begin with an initial SO2Cl2 pressure of 425 torr, what is the pressure of this substance after 74 s? what is the equation to ...
February 2, 2013

science
sorry this was the info given Molecular iodine, I2(g), dissociates into iodine atoms at 625 K with a first-order rate constant of 0.271 s−1.
January 31, 2013

science
If you start with 0.054 M I2 at this temperature, how much will remain after 5.42 s assuming that the iodine atoms do not recombine to form I2?
January 31, 2013

Physics
How much energy is released when 1 gram of steam condenses to water at 100 degrees Celsius?
January 31, 2013

Physics
what is the number of grams of steam at 100 degrees C that will condense as 5g of ice at 0 degrees C melts?
January 31, 2013

physics
if 8100 calories are released from 200g of steam at 100C, how much of the steam condenses?
January 31, 2013

chemistry
i dont know hwo to do any of it
January 30, 2013

chemistry
disappearance of NO in ...- Help!!!? The following data were collected for the rate of disappearance of NO in the reaction 2 NO(g) + O2(g) ¨ 2 NO2(g). Run: [NO](M) [O2](M) Initail Rate (M/s) 1 .0126 .0125 1.41 X 10^-2 2 .0252 .0125 5.64 X 10^-2 3 .0252 .0250 1.13 X ...
January 30, 2013

algebra
Jet #1 leaves an airport at 600 km/h. Jet #2 leaves 3/4 hour after jet #1 in same direction. How long until jet #2 overtakes jet #1
January 28, 2013

Spanish help please.
Acabar de means "to have just." So, acabo de estudiar means "I just studied." You conjugate "acabar," but NOT the verb that follows "de." You always follow a preposition (like de) with a verb that is NOT conjugated (a verb that ends in -...
January 28, 2013

science
Using data from this table of molal boiling-point-elevation and freezing-point-depression constants, calculate the freezing and boiling points of each of the following solutions. a)0.39 m glucose in ethanol (b) 22.8 g of decane, C10H22, in 53.9 g CHCl3 (c) 3.90 g NaOH in 109 g...
January 23, 2013

Chemistry
I did that. doesnt it have to be liters of the total solution? so how do we factor in the asprin into the liters?
January 22, 2013

Chemistry
What is the osmotic pressure formed by dissolving 50.8 mg of aspirin (C9H8O4) in 0.200 L of water at 18°C?
January 22, 2013

math
10+2n=8n-8(+8)
January 22, 2013

Physics
For the problem (8.99 X 10^9 NM^2/c^2)(1 X 10^-6c) / (.1m)^2 = .90 N When I put this in my calculator I did not get .90N. Am I suppose to convert the units to get the answer. Thank you for your help.
January 11, 2013

5th grade math
and how do i do that please
January 8, 2013

5th grade math
I am sorry, can u show your division please. when i divide 87 for 60 i get 1.45. Please help!
January 8, 2013

5th grade math
Hello Ms. Sue, How did you get 15 27/60 please? Thanks, Hannah
January 8, 2013

5th grade math
please help solved the following fraction 11 13/15 + 3 7/12 = 14 3/4 + 7 + 5 7/8 = Thanks, Hannah
January 8, 2013

science
how did the invention of the microscope help doctors to understand what caused diseases.
January 8, 2013

math
I don't know how to change 1/3 and 2 1/3 into a decimal and still show my work
December 19, 2012

Physics
A plane is heading south with a velocity of 150 kilometers/hour. It experiences a tailwind with a velocity of 20 kilometers/hour. Find the resultant velocity of the plane
December 17, 2012

environmental science
why are cultivation practices for pest control not widely used today?
December 16, 2012

physics
Sorry, i have no idea!!! I have a physics final tomorrow!!! Freaking out!!!!
December 13, 2012

algebra
a parking meter gives 30 minutes for each quarter and 6 minutes for each nickel. the equation 30x+6y=60 describes the number of quarters x and nickels y that you need to park for 60 minutes what does the x-intercept represent?
December 12, 2012

social studies
britain passed the stamp act
December 4, 2012

science
fertilization is the union of sperm cell and egg cell
December 1, 2012

science
what is the meaning of fertilization?
December 1, 2012

math
about 7x10 to the power of 3 babies are born each day in the city. about how many babies are born each day in the city?.give the abswer un standard form
December 1, 2012

math
if 3 bananas cost £1.14 how much will 5 of them cost? and how do you work it out?
November 23, 2012

math
if 3 bananas cost £1.14 how much will 5 of them cost? and how do ypu work it out?
November 23, 2012

math
if 3 bananas cost £1.14 how much will 5 of them cost? and how do ypu work it out?
November 23, 2012

math
if 3 bananas cost £1.14 how much will 5 of them cost? and how do ypu work it out?
November 23, 2012

Chemistry
What is the concentration in mol/L of a CuSO4 solution containg 1.0 mole of CuSO4 in 250 mL of Solution? I would like to know how to calculate the answer and be giving the correct answer please.
November 19, 2012

physics
A projectile is launched off of a 18.6 m high cliff with a velocity of 12.8 m/s. If the projectile is launched at an angle of 20° above the horizontal, how far did it travel horizontal before it hit the ground below?
November 15, 2012

english
also i have my introduction written and i need someone to check it over (its in outline form now) A. “I will instruct you and teach you in the way you should go; I will counsel you and watch over you.” Psalm 32:8 B. As the main character in Daniel Defoe’s book, ...
November 15, 2012

english
i am writing a literary research paper on the book robinson crusoe. my thesis is In "Robinson Crusoe" Daniel Defoe uses the protagonist to show the sporadic but guiding relationship between God and man. I am having trouble coming up with a title. So far I have "...
November 15, 2012

Scoial Studies
As a general rule, homeowners should carry property damage insurance on their structures amounting to at least ____ percent of their value (the cost of rebuilding them). A. 50 B. 60 C. 70 D. 80
November 15, 2012

chemistry
a chemist puts 6 moles of nitrogen gas and 7 moles hydrogen gas into an evacuated 1 liter container. The system reaches equilibrium at a certain temperature according to the process outlined above. when the system is at equilibrium the chemist determines the ammonia ...
November 14, 2012

math
Can't remember the way to solve for the variable. 5x + 6 = 7x. Answer is 3, but how to do other problems?
November 11, 2012

algebra
-13=5(1+4m)-2m
November 11, 2012

chemistry
If a saline solution has a concentration of 0.25 g per mL, calculate the following. a) The concentration of this solution in %w/v. b) The concentration of this solution in grams per litre (g/L). c) The concentration of this solution in milligrams per mL (mg/mL).
November 7, 2012

please check my answer
Consider the following equations. N2H4(l) + O2(g) N2(g) + 2 H2O(l) ÄH = -622.2 kJ H2(g) + 1/2 O2(g) H2O(l) ÄH = -258.5 kJ H2(g) + O2(g) H2O2(l) ÄH = -187.8 kJ Use this information to calculate the enthalpy change for the reaction shown below. N2H4(l) + 2 H2O2(l...
November 6, 2012

Math Algr.2
Convert to standard form (AX+BY=C) 1.y=3/2x+6 2. 2/3y=2x-5 3.7y-21=1/2x 4.-2/3x+3/4y=1 Convert to Slope/intercept form (y=mx+b) 1.3x-27=14 2.-9y-6x-18=0 3.8-2x+4y=0 12x=4y-8 I need help going through this because I am not sure if I am doing everything right and I also dont ...
November 6, 2012

chem- i reallyneed help
oops thats me ^
November 6, 2012

chem- i reallyneed help
Consider the following equations. N2H4(l) + O2(g) N2(g) + 2 H2O(l) ÄH = -622.2 kJ H2(g) + 1/2 O2(g) H2O(l) ÄH = -258.5 kJ H2(g) + O2(g) H2O2(l) ÄH = -187.8 kJ Use this information to calculate the enthalpy change for the reaction shown below. N2H4(l) + 2 H2O2(l...
November 6, 2012

chem urgent!
Set up a Hess's law cycle, and use the following information to calculate ÄH°f for aqueous nitric acid, HNO3(aq). You will need to use fractional coefficients for some equations. 3 NO2(g) + H2O(l) 2 HNO3(aq) + NO(g) ÄH° = -138.4 kJ 2 NO(g) + O2(g) 2 NO2(g...
November 6, 2012

chem
(a) When a 4.75-g sample of solid ammonium nitrate dissolves in 60.0 g of water in a coffee-cup calorimeter (see figure), the temperature drops from 23.0‹C to 16.6‹C. Calculate ƒ¢H (in kJ/mol NH4NO3) for the solution process NH4NO3(s) ¨...
November 6, 2012

Algr1
Find the x and y intercept of the equations. 1.5x+6y=-30 2.x-4y=-16 3.-3x+4y=12 How would I solve these and what is the anwsers
November 5, 2012

Algr1
Find the x and y intercept of the equations. 1.5x+6y=-30 2.x-4y=-16 3.-3x+4y=12 How would I solve these and what is the anwsers
November 5, 2012

Algr.1
Find the x and y intercept of the equations. 1.5x+6y=-30 2.x-4y=-16 3.-3x+4y=12 How would I solve these and what is the anwsers
November 5, 2012

Chemistry(Please check)
Thank you!
November 3, 2012

Chemistry(Please check)
For an experiment on specific heat capacities my data for measured specifi heats was consistently higher than the accepted values. I am not sure why this is. Would it be because my initial temperature that I started the experiment with was higher than it should have been? ...
November 3, 2012

Chemistry(Please, please help)
I am trying to draw a constitutional isomer for the compound CH3CH=CHCH3 but I am having some trouble. H-C-C=C-C-H I drew the first compound like this with more hydrogens on the Cs. How could I draw another strucutre?
November 1, 2012

Math(Please check)
Please diregard, I figured out my mistake.
November 1, 2012

Math(Please check)
For an experiment on specific heat capacities of metal in physics, I am trying to calculate my percent error but am having some trouble. After collecting my experimental data for c (cal/g) for the object that was used which was aluminum my results are: trial 1 = .19 trial 2...
November 1, 2012

Math/Physics(Please check work)
Please disregard. I figured out my mistake.
November 1, 2012

Math/Physics(Please check work)
For an experiment on specific heat capacities of metal in physics, I am trying to calculate my percent error but am having some trouble. After collecting my experimental data for c (cal/g) for the object that was used which was aluminum my results are: trial 1 = .19 trial 2...
November 1, 2012

math
964
October 31, 2012

please help
When is the best time to read review or discussion questions? A. Immediately after you have finished all of the reading. B. After you write your notes. C. Before you begin any detailed reading. D. Throughout your detailed reading.
October 30, 2012

Chemistry(Please help)
ok thank you and for the specific rotation of L-erythrose 4-phosphate would it be the same as for D-erythrose 4-phosphate which I determined was 50 or would it be -50?
October 28, 2012

Chemistry(Please help)
The path of length was given in cm so I converted it to dm but I am not sure if I calculated the concentration correctly. A 50 gram sample was dissolved in 10 mL solution so would I do 50/10?
October 28, 2012

Chemistry(Please help)
Oh ok, the question asks me to find the specific rotation for D-erythrose 4-phosphate which I determined was 50 and then it asks me to find the specific optical rotation for L-erythrose 4-phosphate so I thought that it would be a different formula.
October 28, 2012

Chemistry(Please help)
I know that to calculate the specific rotation for a compound you do observed rotation / path length(dm) * conc. (g/ml). I am confused about how to calculate the specific optical rotation for a compound. Thank you for your help!
October 28, 2012

Chemistry(Please check)
Determine if the equation is SN1, SN2,E2 or E1. CH3CH2O- + CH3CH2BR = CH3CH2OCH2CH3 + BR- I think that this is SN2. Would you agree?
October 25, 2012

math
20 Minivans
October 24, 2012

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