Friday
September 19, 2014

Posts by Hannah


Total # Posts: 2,852

Thermochemistry
How many grams of water at 0 degrees C can be frozen into ice at 0 degrees C if 55.0 kJ of heat is removed? delta Hsolid= -6.01 kJ/mol
December 14, 2010

Thermochemistry
3CO(g)+ Fe2O3(s) --> 2Fe(s) + 3CO2(g) + 24.7 kJ. How much heat is released when 56 grams of CO react?
December 14, 2010

Chemistry
The molar heat of solution of NH4NO3 is 25.7 kJ/mol. How much heat (in kJ) would be required to dissolve 20 grams of NH4NO3 in water?
December 14, 2010

Chemistry
How much heat is required to convert 9 grams of water at 100 degrees C into steam at 100 degrees C. Hvap for water = 40.7 kJ/mol
December 14, 2010

Chemistry
Si(s)+ 2Cl2(g) --> SiCl2(g) --> SiCl2(l) + 687 kJ. How much heat is produced when 106 grams of Cl2 react?
December 14, 2010

Chemistry
A student mixes two water solutions with an initial temperature of 25 degrees C to form a final substance with a mass of 65 grams at 30 degrees C. What is the heat change in kJ?
December 14, 2010

Chemistry
How much heat in kJ is required to melt 54 grams of ice at 0 degrees C into water at 0 degrees C if delta Hvap for water = 6.01 kJ/mol?
December 14, 2010

Chemistry
How many calories are required to raise the temperature of 75 grams of water from 20 degrees C to 50 degrees C?
December 14, 2010

question about corrections(what they mean)
ok thanks:)
December 13, 2010

question about corrections(what they mean)
ok. so this may be hard to explain and may not be enough info that you understand but ill try. I did a paper and my teacher corrected it and said changes i need to make. here is a clip from the paper of something that she commented on: " Here are some examples. Hard Tack ...
December 13, 2010

english- need a creative title!
thanks for the idea. That would probably work but I don't know if my teacher would understand it because that is not one of the slang words i described in my paper. do you have any other ideas?
December 13, 2010

english- need a creative title!
For my english class i had to right a paper on civil war slang and how this topic releated to the book The Red Badge of Courage. I finished my paper but have no idea of a creative title. Im not good at thinking up good titles :/ have any ideas?
December 13, 2010

Algebra
why is any real number a solution for the equation 8y - 30 = 4(2y - 7.5)
December 12, 2010

chem
i dont think 34 is correct because that is way more than 10% of my first answer of 5.7
December 11, 2010

chem
Some sulfuric acid is spilled on a lab bench. It can be neutralized by sprinkling sodium bicarbonate on it and then mopping up the resultant solution. The sodium bicarbonate reacts with sulfuric acid as follows. 2 NaHCO3(s) + H2SO4(aq) --> Na2SO4(aq) + 2 H2O(l) + 2 CO2(g) ...
December 11, 2010

Math
A population is 200 in the year 1825, 252 in 1850, and 318 in 1875. What is the p(t) equation? I see that the population increases 26% over each 25-year period but I can't figure out the equation.
December 9, 2010

Math
Dina earned 1/4 for baby sitting and 1/2 for washing the dishes. How much money did she NOT earn from $25.00?
December 9, 2010

Geometry
sam..? im assuming just like the others we cannot see your documents so we don't know what the picture looks like. sorry
December 9, 2010

chem
thanks for the help: can you help me with another one? Some sulfuric acid is spilled on a lab bench. It can be neutralized by sprinkling sodium bicarbonate on it and then mopping up the resultant solution. The sodium bicarbonate reacts with sulfuric acid as follows. 2 NaHCO3(s...
December 9, 2010

chem
thanks so its 5.21 L h2?
December 9, 2010

chem
2Al(s) + 2NaOH(aq) + 2H2O(l) 2NaAlO2(aq) + 3H2(g) (unbalanced) sorry i forgot. it was unbalanced but then i balance it
December 9, 2010

chem
Calculate the number of liters of hydrogen, measured at STP, that can be produced from the reaction of 0.155 mol of aluminum according to the following unbalanced chemical reaction equation. i got .193 L of H2 but it was wrong. i only have one submition left!
December 9, 2010

Geometry Please Help
im sorry your link/document doesnt work
December 9, 2010

chem- plz check my work
2. Given the following equation, C2H5OH(l) + 3 O2(g)---> 2 CO2(g) + 3 H2O(l) How many liter of CO2 are expected in the combustion of 12.0 grams of ethanol? My work: 12.0g C2H5OH X 1 mol C2H5OH/46.08g C2H5OH X 2 mol CO2/1 molC2H5OH X 22.4L CO2/1 mol CO2 = 11.7 L CO2 all i ...
December 8, 2010

chemisty
when looking at a chemical equation what are the evidences that a chemical reaction has occured. Or what is the evidence that it has not occured thanks:):) <3
December 8, 2010

Physics
What is the volume of 3.25 moles of a gas at a temperature of 115 K and a pressure of 275 kPa?
December 8, 2010

Physics
A pendulum is constructed of a 6.7 gram mass suspended on a 55cm thread. The mass is displaced vertically 55 cm to a point exactly horizontal from the top of the thread and released. The mass swings down and is cut directly above the mass when the mass is 120 cm above the ...
December 7, 2010

CHOIR
can you find the music online? Why not just ask her for another copy when you get to school tomorrow and tell her what happened
December 7, 2010

english
I need two examples where in the book Huckleberry finn. Huck doesn't believe in himself or he is having self doubt. does anyone know an example or two where this happens in the book? thanks
December 7, 2010

chem
how would you find the answer? A carbon nucleus has six protons and six neutrons. How many electrons would it take to equal the mass of a carbon nucleus?
December 6, 2010

chem
can you explain? For each of the reactions shown, calculate how many grams of the product form when 16.8 g of the reactant in bold completely reacts. Assume that there is more than enough of the other reactant. 4 Cr(s) + 3 O2(g) 2 Cr2O3(s) thanks
December 6, 2010

huckleberry finn
in the book huckleberry finn manys words are used that mean something like "to beat someone" for example to lick. i need to find 8 more of words that are used to mean "to beat" if you know any and the page number/chapter it is used in the book that would be...
December 5, 2010

Chemistry
because you take the ratio and just use them as subscripts for its corresponding element. So if carbon came out to 2 and hydrogen came out to 6, then it would simply be C2H6.
December 4, 2010

Chemistry
It would be C2H6
December 4, 2010

Calculus
Find the unique solution to the differential equation y"?1y'?6y=?24(t^2)+10t+41 satisfying the initial conditions y(0)=?6 and y'(0)=?26
December 3, 2010

Calculus
(1 pt) Find the unique solution to the differential equation y"?5y'+6y=?312sin(2t) satisfying the initial conditions y(0)=?31 and y'(0)=?18
December 3, 2010

Geometry
You do 1/2 base times height, so 1/2(14cm)(18cm)=126cm. Dont forget units! Your welcome:)
December 1, 2010

Math fractions
You must make the denominators the same by multiplying the numerator and the denominator of 1/2 by four to get 4/8. Your welcome:)
December 1, 2010

huckleberry finn
also the word valley on page 174( at least in my book) its in the context that reads "the king said the cubby would do for his valley- meaning me"
December 1, 2010

huckleberry finn
what is the definition of dauphin this huckleberry finn? I searched on the internet but there were so many i didnt know which one was used in the book
December 1, 2010

math
Use a table of values to graph the equation. solve for y x= -1,0,1 y= y=2/3x+6
November 30, 2010

chem
I got it:) it was just not a precipitate:) Thankyou sooooo much:)
November 30, 2010

chem
could it also be an acid-base?
November 30, 2010

chem
or acid- base? because i did gas evolution oxidation-reduction precipitation single-displacement but got it wrong so I am thinking either one of those has to be taken out and/or acid-base added
November 30, 2010

chem
its not also a precipitation os single-displacement??
November 30, 2010

chem
Ca(s) + 2 H2O(l) Ca(OH)2(aq) + H2(g) acid-base double-displacement gas evolution oxidation-reduction precipitation single-displacement synthesis whichs one(s) is it?? thanks
November 30, 2010

chem
oops sorry
November 30, 2010

chem
thanks you so much. Also if i may ask im having trouble on another type of problem balancing this equation: C5H12O(l) + O2(g) --> H2O(g) + find the compound here I am able to balance it but i need to find the last compound i though it would be: C5H10O2 because i took out 2 ...
November 30, 2010

chem
thanks. so would it be double displacement and acid-base?
November 30, 2010

chem
Classify each of the following reactions in as many ways as possible. (Select all that apply.) CuO + 2 HCl --> CuCl2 + H2O you can select: -acid-base(unsure because there is an acid but im not sure if theres a base) -double-displacement -gas evolutionx -oxidation-reduction ...
November 30, 2010

Geometry
SORRY I FORGOT SOME QUESTI IN MY LAST POST!!! The lengths of two sides of a triangle are given. Describe the possible lenths for the third side. 19.) 5,11 20.) 12,12 21.) 25,10 22.) 6,8 25.) A student draws a triangle with a perimeter 36 cm. The students says that the longest ...
November 29, 2010

Geometry
THANK YOU SO MUCH!
November 29, 2010

Geometry
Can a triangle have sides with the given lengths? Explain. 15) 8cm, 7cm, 9cm 16) 7ft, 13ft, 6ft 17) 20in, 18in, 16in 18) 3m, 11m, 7m
November 29, 2010

chem
oh sorry i miss read what you put. thanks
November 29, 2010

chem
oh theres an arrown after Br2
November 29, 2010

chem
so is it just synthesis?
November 29, 2010

chem
I am having lots of trouble with these questions: Classify each of the following reactions in as many ways as possible. (Select all that apply.) a)2 Rb(s) + Br2(g) 2 RbBr(s) you can select: -acid-base -double-displacement -gas evolution -oxidation-reduction -precipitation -...
November 29, 2010

Health
what is the drug classification of inhalants?
November 28, 2010

french, english
oh thanks sooo much:)
November 28, 2010

chem
oh i got it:) thanks:)
November 28, 2010

math
48 is another one
November 28, 2010

OMG
The main teachers that are on this site that specialize in your subject just might not be on around this time. be patient and give it time and im sure someone will be able to help :)
November 28, 2010

chem
balance the equation:(i can balance the equation but the problem i have is finding the formula for the last part HC2H3O2(aq) + Ca(OH)2(aq) -> H2O(l) + find the formula here the last part would be CaOC2H3O2? im a little confused. did the O fromt he H2O come from (OH)2?
November 28, 2010

chem
thanks so for this equation: HC2H3O2(aq) + Ca(OH)2(aq) -> H2O(l) + find the formula here the last part would be CaOC2H3O2? im a little confused. did the O fromt he H2O come from (OH)2?
November 27, 2010

chem
balance the formula Cu(OH)2(s) + HNO3(aq) -> H2O(l) + fine the formula here(aq) i did the H20 but i don't know the other formula i thought it was CuNO3 but thats wrong and idk what to do with the extra O
November 27, 2010

math brain teaser
more it it thani what does that mean??? also: EVELATOR and: DENTURES E F
November 24, 2010

geometry
use the a^2 + b^2 = c^2 c being the length of the hypotenuse
November 23, 2010

chem
I need major help im not understanding this at all: Complete and balance each of the following equations for acid-base reactions. (Type your answer using the format CO2 for CO2 and Al(OH)3 for Al(OH)3. Use the lowest possible coefficients.) HBr(aq) + LiOH(aq) -> find this ...
November 23, 2010

history
I would say D also :)
November 23, 2010

chem
thanks sooo much!!
November 23, 2010

chem
this is what it says: For the soluble compounds, write the ions present in solution. this is the soluble compound: Na3PO4 then it has 2 boxes one called cations and one called anions
November 23, 2010

chem
it says those answers are wrong
November 23, 2010

chem
I put Na+ as the cation and it counted it wrong. also. are you saying PO4- is the anion? cause i got it wrong. and what do the noble gases have to do with the ions. sorry im asking many questions
November 23, 2010

chem
can you explain more? i put the cation was Na3+ and the anion was PO4-. but it said it was wrong. what am i doing wrong?
November 23, 2010

chem
how do i know what the ions present are of this formula: Na3PO4 what are the anions and what are the cations? how do you know
November 23, 2010

Math
Thank you!!!
November 22, 2010

Math
An object is heated to 90 degrees Celcius and is then allowed to cool in a room whose air temperature is 25 degrees celcius. If the temperature of the object is 75 degrees celcius after 10 minutes, when will its temperature be 50 degrees celcius?
November 22, 2010

chem
Balance the skeletal equation for the synthesis of urea. (Enter 0 for any empty boxes. Use the lowest possible coefficients.) _NH3 + _CO2 ¨ _CO(NH2)2 + _H2O in the _ goes a number
November 22, 2010

maths
well it has to end in 0 to be divisible by 10. I got:360 because 8 and 9 both go in evenly
November 22, 2010

maths
i am divisible by 8 and9.i am a three digit multiple of 10. i am between 200 and 700.
November 22, 2010

chem
nevermind i got it
November 22, 2010

chem
Aluminum hydroxide and sulfuric acid neutralize to make water and aluminum sulfate. the first step i have done: Al(OH)3 + H2SO4 -> H2O + Al2(SO4)3 i find this one confusing XD
November 22, 2010

chem repost
I got most of it but there is one coefficient its counting wrong. i posted my problem on the previous post. would you like me to post it here also?
November 21, 2010

chem repost
oh. sorry i didn't see my other post was answered thanks
November 21, 2010

chem repost
write a balanced equation for:Gaseous carbon dioxide and liquid water react to produce aqueous glucose (C6H12O6) and oxygen gas. I try but everytime i change the coefficient it makes the other elements unbalanced. the starting formula i got was: CO2(g) + H2O(l) -> C6H12O6(...
November 21, 2010

Math
An object is heated to 90 degrees Celcius and is then allowed to cool in a room whose air temperature is 25 degrees celcius. If the temperature of the object is 75 degrees celcius after 10 minutes, when will its temperature be 50 degrees celcius? I have no idea how to do this...
November 21, 2010

chem
thanks! i didnt see the 2 after the H
November 21, 2010

chem
so what i have so far is: 6-CO2(g) + 12- H2O(l) -> 1-C6H12O6(aq) + 6- O2(g) it said all the coefficients were correct except the 12 in front of the H20 how is that wrong?
November 21, 2010

chem
write a balanced equation for:Gaseous carbon dioxide and liquid water react to produce aqueous glucose (C6H12O6) and oxygen gas. I try but everytime i change the coefficient it makes the other elements unbalanced. the starting formula i got was: CO2(g) + H2O(l) -> C6H12O6(...
November 21, 2010

Math
An object is heated to 90 degrees Celcius and is then allowed to cool in a room whose air temperature is 25 degrees celcius. If the temperature of the object is 75 degrees celcius after 10 minutes, when will its temperature be 50 degrees celcius? I have no idea how to do this...
November 21, 2010

Math
Thank You
November 20, 2010

Math
A bone is found to have 45% of the original amount of carbon 14. If the half life of carbon is 5600 years, how old is the bone. Would I use the formula N=No e^kt?
November 20, 2010

Math
Thank You
November 20, 2010

Math
A colony of bacteria increases according to the law of unihabited growth. a) If the number of bacteria doubles in 5 hours, find the function that gives the number of cells in the culture. I have the answer to this one. It is N=No e ln2/5 (t) b) If there are 10,000 cells ...
November 20, 2010

chem
is An antacid neutralizes stomach acid. a chemical reaction?
November 20, 2010

7th grade
unless you just look to the next chapter of your text book if its something like math and you read that and try to understand it.
November 20, 2010

Calculus
Find the particular solution of the differential equation y'=(5x+21y)/7x satisfying the initial condition y(1)=5.
November 18, 2010

Calculus
1)Find the particular solution of the differential equation xy'+3y=80xlnx (x>0) satisfying the initial condition y(1)=4 2)Find the particular solution of the differential equation y'−1y=−5x+3 satisfying the initial condition y(0)=3.
November 18, 2010

precal
Find the value of sec theta for angle theta in standard position if the point at (–2, –4) lies on its terminal side. If 0° lessthanorequalto x lessthanorequalto 360°, solve the equation sec x = –2. The terminal side of an angle theta in standard position...
November 17, 2010

Ethics
What is speciesism? I have already defined it on google but could simply the definition?
November 16, 2010

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