Wednesday

May 4, 2016
Total # Posts: 3,195

**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*

**chem**

The rock in a lead ore deposit contains 84% PbS by mass. How many kilograms of the rock must be processed to obtain 1.1 kg of Pb? i need to know what the conversion factors look like and how u did it
*November 16, 2010*

**physics**

5 m/s
*November 16, 2010*

**social studies**

how did the Nile and the surrounding area help protect Egypt?
*November 16, 2010*

**chem**

thanks!!!
*November 15, 2010*

**chem**

i had posted this question about a week ago and had gotten help from bobpursley(thank you so much btw) but i was showed how to do it using an equationa and now when im studying for the test i realize i need to be able to make a conversion factor to solve it. so heres the ...
*November 15, 2010*

**english**

thats a little helpful but im kinda looking more for why the slang was used. was it easier for them?faster? and how did it all start up? did the soldiers just start using the words and everyone learned them? things like that
*November 15, 2010*

**english**

For english i need to write a paper of the the slang words used during the civil war. I already have many examples but i cant seem to find history or facts about it. am information that you know would be helpful like origin, history,who came up with the words etc. thanks so ...
*November 15, 2010*

**physics**

What length pendulum will produce a period of 1.0s?
*November 14, 2010*

**physics**

you measure the period of a 2.0m pendulum and find it is 2.8s. what is the value of g at your location?
*November 14, 2010*

**math **

5^3= 5x5x5= 125 5^7=5x5x5x5x5x5x5= 78125
*November 14, 2010*

**chem**

Citric acid, the compound responsible for the sour taste of lemons, has the following elemental composition: C, 37.51%; H, 4.20%; O, 58.29%. Calculate the empirical formula of citric acid. (Type your answer using the format CO2 for CO2.) thanks
*November 14, 2010*

**physics**

If the coefficient of kinetic friction between a 37 kg crate and the floor is 0.31, what horizontal force is required to move the crate at a steady speed across the floor? What horizontal force is required if µk is zero?
*November 14, 2010*

**physics**

A person jumps from the roof of a house 4.9 m high. When he strikes the ground below, he bends his knees so that his torso decelerates over an approximate distance of 0.70 m. The mass of his torso (excluding legs) is 46 kg. (a) Find his velocity just before his feet strike the...
*November 14, 2010*

**chem**

A 2.241 g sample of nickel reacts with oxygen to form 2.852 g of the metal oxide. Calculate the empirical formula of the oxide. 1)NiO Give the number of moles of each element to support you answer. moles of Ni 2) 1.339 mol moles of O 3)1.34 mol I know #1 is correct but 2 and 3...
*November 12, 2010*

**science**

suppose you had two samples of the same radioactive isotope. one sample had a mass of 25 grams. the other had a mass of 50 grams. would the same number of particles be ejected from each sample in the first hour? explain
*November 11, 2010*

**chem**

oh i see! thanks
*November 11, 2010*

**chem**

shouldn't it be less than the 4.7 g of silver plating??
*November 11, 2010*

**chem**

so the mass would be 6.24g?
*November 11, 2010*

**chem**

Silver chloride, often used in silver plating, contains 75.27% Ag. Calculate the mass of silver chloride in grams required to make 4.7 g of silver plating.
*November 11, 2010*

**chem**

i got the answer. thanks anyways!
*November 11, 2010*

**chem**

A 4.91 g sample of aluminum completely reacts with oxygen to form 6.85 g of aluminum oxide. Use this data to calculate the mass percent composition of aluminum in aluminum oxide. i got 61.2% first and it was wrong. then i got 53.0% and it was wrong
*November 11, 2010*

**Math**

I figured it out. -8=1/3x+x -8*3=1/3x*3+x -24=3x+x -24=4x -24/4+4x/4 -6=x -8=1/3*-6+-6 -8=-6/3-6 -8=-2-6 -8=-8
*November 10, 2010*

**Math**

-8=1/3x+x
*November 10, 2010*

**chem**

I used that answer and it was wrong. we have a practice version : the question was A salt crystal has a mass of 0.18 mg. How many NaCl formula units does it contain? and the answer was 1.9e+18 formula units. so wouldn't the answer for my question be in the positive exponents?
*November 10, 2010*

**chem**

so i posted this question yesturday and got some help. which is the stuff below. can you look at the last thing i said which was the answer i got by doing what DrBob222 said to do and tell me if its correct.(the question is the first section) thanks chem - hannah, A salt ...
*November 10, 2010*

**social studies**

1. Cuzco 2. are there many? this is what i found. In 1528, Emperor Huayna Capac (Young Lord) ruled the Inca Empire 3.Mound Builders
*November 10, 2010*

**math**

substract 3 from the right side and left eg- -1=3+4x -3 -3 then divide by 4 on the right and left side. eg- -4/4=4x/4 x=-1
*November 10, 2010*

**math**

first we want to get the like terms on the same side. so lets subtract 3 from both sides you get -4=4x then since we want x by itself we divide by 4 on both sides making the 4 cross out and we get -1=x
*November 10, 2010*

**Spanish 1**

the first 3 are def. correct. for the last one it seems like many could work. im not sure about that one either sorry but if i had to guess id think either a or b
*November 10, 2010*

**Spanish 1**

a)a-there b)d- a pencil
*November 9, 2010*

**math**

estimating quotients 811 divided by 2
*November 9, 2010*

**chem**

thanks so much!
*November 9, 2010*

**chem**

How many moles of O are in 13.5 mol Fe(NO3)3? i got 7.32e25 but soon realized that is totally wrong.
*November 9, 2010*

**chem**

so it would be .000006845 formula units?
*November 9, 2010*

**chem**

so do i have to convert .4 mg to grams first? that would be .0004 right? so then i just divide .004/58.44 and that will be my answer?
*November 9, 2010*

**chem**

nevermind i got the answer but i do have another question: A salt crystal has a mass of 0.40 mg. How many NaCl formula units does it contain?
*November 9, 2010*

**chem**

Determine the mass(in grams) of each of the following compounds. a) 0.709 mol magnesium fluoride i got 30.7grams but it was wrong. id appreciate the help! thanks! also if i end up getting the help i have a couple other questions
*November 9, 2010*

**Math(Please help)**

Show that (f X g)(x) = (g X f)(x) = x for f(x)= 3x-5 and g(x)= x+5 / 3 I have know idea how to do this.
*November 8, 2010*

**Math**

Find the inverse of the function f(x) = x / 2x+1 I know that you would make this x= y / 2x+1 but now I do not know what to do.
*November 8, 2010*

**Math**

Find the domain of (f X g)(x) if f(x) = 2 / x-3 and g(x) = 1 / x+4. I know the domain for g(x) is x cannot be -4 but I do not know what else to do.
*November 7, 2010*

**Math**

Find the inverse of the function f(x) = x / 2x+1 I know that you would make this x= y / 2x+1 but now I do not know what to do.
*November 7, 2010*

**chemistry**

The molality of a solute is the number of moles of that solute divided by the weight of the solvent in kilograms
*November 4, 2010*

**Math**

The following function f is one-to-one; find its domain and range. f(x) = 5 / x+3 Domain = x cannot be -3 Range= I do not know how to find this.
*November 4, 2010*

**Math(Please check)**

Sorry I already post this. Disregard this one.
*November 4, 2010*

**Math(Please check)**

Find the domain of the following rational function. R(x) = -3x^2 / x^2 + 2x - 48 (x+8)(x-6) So domain is x cannot be 8 or -6. Am I correct?
*November 4, 2010*

**Math(Please check)**

Find the domain of the following rational function. R(x) = -3x^2 / x^2 + 2x - 48 (x+8)(x-6) So the domain is x cannot be 8 or -6. Am I correct?
*November 4, 2010*

**math**

Thank You!
*November 4, 2010*

**math**

The function D(h)=7e^-0.4(h) can be used to determine the milligrams D of a certain drug in a patient's bloodstream h hours after the drug has been given. How many milligrams will be present after 9 hours. Round three decimal places. so 7e^(-0.4 x 9) = .191 To get this ...
*November 4, 2010*

**English**

Thank you!
*November 3, 2010*

**English**

Most people think of bamboo as a tree or a bush. Is this transitive or intransitive? think = transitive
*November 3, 2010*

**Math**

The function D(h)=7e^-0.4(h) can be used to determine the milligrams D of a certain drug in a patient's bloodstream h hours after the drug has been given. How many milligrams will be present after 9 hours. Round three decimal places. so 7e^(-0.4 x 9) = .191 To get this ...
*November 3, 2010*

**Math**

Find the x and y intercepts of the following function. f(x) = 9x - x^3
*November 3, 2010*

**Math(Quick question)**

The function D(h)=7e^-0.4(h) can be used to determine the milligrams D of a certain drug in a patient's bloodstream h hours after the drug has been given. How many milligrams will be present after 9 hours. Round three decimal places. so 7e^(-0.4 x 9) = .191 To get this ...
*November 3, 2010*

**Math(Please check)**

O ok I understand. Thanks!!
*November 3, 2010*

**Math(Please check)**

So what is the inverse?
*November 3, 2010*

**Math(Please check)**

The following function is one-to-one; find its inverse f(x)=x^3+5 I know that the first step would be to set y = to x so I did y=x^3+5 Then you swap x with y so x=y^3+5. Then you solve for y and this is where I think i messed up. I did y^3=x-5 = y=x^3-5 Then the inverse would ...
*November 3, 2010*

**Maths**

What is dy/dx of e^-x ?
*November 2, 2010*

**elementary functions**

(x-4)(x+1)
*November 2, 2010*

**algebra**

1. (4x-3)(x-1) 2. Use the quadratic formula which you can find on youtube.
*November 2, 2010*

**Maths**

if f(x) = 2x - x ln x show that f(e^3) = -e^3 I know you have to substitute e^3 into the function, so Ive sone ths so far: 2e^3 - e^3 ln e^3 What is the next step?
*November 1, 2010*

**MATH**

you do do 24 divided by 8 and then times it by 7.
*November 1, 2010*

**Maths**

if f(x) = 2x - x ln x show that f(e^3) = -e^3 I know you have to substitute e^3 into the function, so Ive sone ths so far: 2e^3 - e^3 ln e^3 What is the next step?
*November 1, 2010*

**Calculus **

Determine whether the integral is divergent or convergent. If it is convergent, evaluate it and enter that value as your answer. If it diverges to infinity, state your answer as "INF" (without the quotation marks). If it diverges to negative infinity, state your ...
*October 22, 2010*

**Calculus **

Find the area between the curves y=(x^3)-10(x^2)+24x and y=(-x^3)+10(x^2)-24x
*October 22, 2010*