Monday
September 1, 2014

Posts by Hannah


Total # Posts: 2,832

chem
Which of the following could be added to a solution of sodium acetate to produce a buffer? ? A) acetic acid only B) acetic acid or hydrochloric acid C) potassium acetate only D) sodium chloride or potassium acetate E) hydrochloric acid only i knowt he answer is b but i dont ...
March 31, 2013

chem
how do i do the ^4 when there is an x and it is a bionomial. i am having trouble
March 28, 2013

chem
In an excess of NH3(aq), Cu2+ ion forms a deep blue complex ion, Cu(NH3)42+, which has a formation constant Kf = 5.6 1011. Calculate the Cu2+ concentration in a solution prepared by adding 4.8 10-3 mol of CuSO4 to 0.500 L of 0.32 M NH3.
March 28, 2013

government
how did the watergate scandal gain attention? and why was an investigation launched?
March 28, 2013

chemistry
Calculate the solubility of Mn(OH)2 in grams per liter when buffered at each of the following. (a) pH 7.7 (b) pH 9.6 (c) pH 11.3
March 27, 2013

chem
The molar solubility of MgF2 at 25°C is 1.2 10-3 mol/L. Calculate Ksp. i got the euqation ksp= [F-]^2[Mg]2+ and plugged in 1.2e-3 and got 1.7e-9 but it is wrong. also this question If 0.0968 g of CaF2 dissolves per liter of solution, calculate the solubility-product ...
March 26, 2013

chem
Consider the titration of 30.0 mL of 0.050 M NH3 with 0.025 M HCl. Calculate the pH after the following volumes of titrant have been added. (The Kb for NH3 is 1.8e-05.) (a) 0 mL . (b) 25.0 mL . (c) 59.0 mL . (d) 60.0 mL (e) 63.0 mL (f) 67.5 mL
March 25, 2013

government
I have serrched her name under google but still have not found what i need. what does committee membership mean? isnt she just a senator? and i cant find her party duties
March 25, 2013

government
I am doing a research paper on senator Debbie Stabenow and I cant find some information. What are her years of experience, committee membership and party duties? also how is she viewed by different special interst groups? thanks!
March 25, 2013

math
Classify each statement as sometimes, always, or never true. A. 2^(2/3)*4^(4/3)=8*2^(1/3) B. If x>0, then (squareroot x*squareroot 2)^3 =x^(3/2) 2^(3/2) C. If x>0, then (squareroot x+ squareroot 2)^3 =x^(3/2) 2^(3/2) D. The only solution to x^(2/3)= 4 is x=8
March 24, 2013

chem
Assume that 35.0 mL of a 0.13 M solution of a weak base B that accepts one proton is titrated with a 0.13 M solution of the monoprotic strong acid HX. (a) How many moles of HX have been added at the equivalence point?
March 24, 2013

chem
i am confused how you got the .0444?
March 23, 2013

chem
Calculate the pH at the equivalence point in titrating 0.100 M solutions of each of the following with 0.080 M NaOH. chlorous acid (HClO2) benzoic acid (C6H5COOH)
March 23, 2013

AP Physics
A small block with mass 0.035 kg slides in a vertical circle of radius 0.425 m on the inside of a circular track. During one of the revolutions of the block, when the block is at the bottom of its path, point A, the magnitude of the normal force exerted on the block by the ...
March 22, 2013

physics
Why is an echo weaker than the original sound? 1. The echo has a shorter wavelength than the original sound due to the reflection. 2. The echo has a smaller amplitude than the original sound because sound spreads and its intensity decreases with distance. 3. The echo has...
March 21, 2013

physics
If the intensity of a person’s voice is 3.6×10−7 W/m2 at a distance of 2.1 m, how much sound power does that person generate? Answer in units of W
March 21, 2013

chem
How many grams of NH4Cl must be added to 0.560 L of 1.90 M NH3 solution to yield a buffer solution with a pH of 8.50? Assume no volume change. Kb for NH3 = 1.8 10-5. i am confused as how to find the grams?
March 19, 2013

chem
What CH3COONa concentration is required to prepare a buffer solution with a pH of 4.80 if [CH3COOH] = 0.150 M? Ka of CH3COOH = 1.8 10-5.
March 19, 2013

chemistry
at the bottom i put a)more acidic? b)less acidic? c)will noit chnage d)less
March 19, 2013

chemistry
thanks! were my c and a correct?
March 19, 2013

chemistry
Acetic acid, CH3CO2H, is the active ingredient in vinegar. It's often abbreviated "HOAc". Vinegar is acidic because acetic acid makes H3O+ when it partially ionizes in water: HOAc(aq) + H2O H3O+(aq) + OAc–(aq) Suppose that you have a solution of acetic acid ...
March 19, 2013

chem
so how do i know if the ph is changing?
March 18, 2013

chem
Indicate whether the pH increases, decreases, or remains the same when each of the following is added. (CH3NH3)Cl to a solution of CH3NH2 pyridinium nitrate, (C5H5NH)(NO3) to a solution of pyridine, C5H5N sodium formate to a solution of formic acid how do you know these?
March 18, 2013

chemistry
use a calulater
March 12, 2013

gepmetry
what grade science is this so i can help you
March 12, 2013

Chem
hi dan can you help me please on the science tab and it has my name on it hannah please thank you very much and have a very wonderful day
March 12, 2013

science
Ecological ________ - normal, gradual changes that occur in the types of species that live in an area. Help please and help me fast please!!!!!
March 12, 2013

biology
if you want to know what it is then go to google and type in your question and there you go and remember to click on the first link to the question so thst way you can know what the correct answer is!!!!!!!!!!
March 12, 2013

chemistry
thanks! also for this question Calculate the hydronium ion concentration and pH in a 0.037 M solution of sodium formate, NaHCO2. hydronium ion concentration I made an equation: k=x^2/.037-x but when i look up the k what compound am i looking for? how do i know?
March 7, 2013

chemistry
For each of the following reactions, predict whether the equilibrium lies predominantly to the left or to the right. HCN(aq) + SO42-(aq) CN -(aq) + HSO4-(aq) I think it has something to do with the Ka but im not sure!
March 7, 2013

physics
An ocean wave travels 17.1 m in 6.7 s. The distance between the two nearest wave crests is 5.1 m. What is the frequency of the wave? Answer in units of H
March 4, 2013

social studies!!!
Why don't you try to look up the textbook online for that just go on google and type in what your textbook name is and try it! And TELL ME IF IT WORKS OR NOT!!!
March 4, 2013

math
NOOOOO THAT IS NOT WHAT I MENT I MEANT BY THERE SELFS WHEN THEY HAVE NUMBERS AROUND THE SHAPES AND YOU HAVE TO MULTIPLY THE NUMBERS BY BASE AND THE HIEGHT!!!!!
March 4, 2013

math
For MATH and its call MULTIPLYING TRAPEZOIDS AND TRIANGLES?
March 4, 2013

math
hi my name is Hannah and I need help with my math homework it is something to do with multiplying trapezoids and triangles? Also, what are the formula for the shapes so that way i would be able to do my homework? THANKS FOR THE HELP!!!!!!
March 4, 2013

chemistry
Phenylacetic acid (C6H5CH2COOH) is one of the substances that accumulates in the blood of people with phenylketonuria, an inherited disorder that can cause mental retardation or even death. A 0.021 M solution of C6H5CH2COOH has a pH of 2.99. Calculate the Ka value for this ...
March 4, 2013

chem
Calculate [OH- ] and pH for each of the following strong base solutions. (Kw = 1.0 10-14.) 3.155 g of KOH in 460.0 mL of solution] how do you do this
March 3, 2013

Chemistry
How many grams of carbon are in 4.30×1023 molecules of (C3H5)2S?
March 3, 2013

chemistry
a similar problem i am having troube with is 15.10 mL of 2.00 M HCl diluted to 0.530 L
March 2, 2013

chemistry
Calculate the pH of each of the following strong acid solutions. 0.697 g of HClO3 in 2.97 L of solution. so i convenrted grams to moles then moles/L to get M of HCl03 then i did -log of that cocentration and put htat as the ph. did i do something wrong? i got 2.415 but it was ...
March 2, 2013

physics
what caused a little puddle of water to appear under the syringe tip after ten minutes in the sun?
February 27, 2013

chemistry
why is HS- a stronger BL base compared to HSO4 In a series of oxybases with the same central atom, the base with more O atoms is stronger. In a series of oxybases with the same central atom, the base with less O atoms is stronger. Since H2SO4 is one of the seven strong acids, ...
February 26, 2013

health
What is atmospheric pressure? A. Pressure of the air inside the body B. Pressure of the air outside the body C. Pressure of the air within one’s mouth D. Pressure of the air within one’s lungs i think its D
February 25, 2013

math
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

calc
The equation is 94000e^(0.03t)
February 22, 2013

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

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