Wednesday
July 23, 2014

Posts by Lauren


Total # Posts: 1,509

Chemistry
Concentrated aqueous ammonia contains 1.00 mol NH3 dissolved in 2.44 mol H20. What is the mole fraction of NH3 in concentrated aqueous ammonia? What is the molal concentration of NH3

algebra
i think its 216

algebra
alright thanks anyway

algebra
but then the directions say variable substitution

algebra
so is that it?? simple as that?

algebra
so then its x^2-6 =0 and ^2-3=0 and the dont i put the root sign over the x^2 to get rid of the x^2? and then i end up with x + or - the suare root of 6 = 0 or is that wrong??

algebra
is it (x^2 - 6) (x^2 - 3) ??

algebra
use variable substitution and factoring to find all of the roots of each equation. x^4-9x^2+18=0 how do you do this??

Chemistry
ok i know how to figure out the 2nd equation 45.0g CHCl3(1 mols/118gCHCl3)=.381 mols CHCl3 but how do you get molarity. with kg solvent

Chemistry
Caffeine C8H10N4O2, is a stimulant found in a tea and coffee. A sample of the substance was dissolved in 45.0g of choloroform CHCl3 to give a 0.0946m solution. How many grams of caffine were in the sample. m = molality

Chemistry
29.575/455*100=6.5% Yay :)

Chemistry
so then i did it wrong... :( is it 142g for the Na2SO4 that needs to be put into there

Chemistry
How would you prepare 455 g of aqueous solution that is 6.50% sodium sulfate Na2SO4 by mass? percent by mass = grams/100 g solution. X grams/455 = 0.065 solve for X. Subtract 455-X to calculate how much water must be added. ok i got -454.935 is this right

Chemistry
23.0769 right

Chemistry
so for this part (g Na2SO4/g solution) = (1.50 g Na2SO4/x g solution). it would be (g Na2SO4/ .065 g solution = 1.50 g Na2SO4/ x .065 g solution ) or did i miss place them

Chemistry
What mass of solution containing 6.50% sodium sulfate N2SO4 by mass contains 1.50g Na2SO4 Set up a proportion. (g Na2SO4/g solution) = (1.50 g Na2SO4/x g solution). Solve for x. Check my work. how do you fine g solution

Chemistry
Determine the mass of the element. What element is it? what is the molar volume of the metal in cubic centimeters(avogadro's number should be used for this problem -1cm=10^7 nm)

Chemistry
What is the molar volume of the metal in cubic centimeters? (Avogadro's number should be used for this problem ------ 1 cm = 10^7 nm what is the molar volume of the metal in cubic centimeters(avogadro's number should be used for this problem -1cm=10^7 nm)

Chemistry
The question is what is the volume of the unit cell? I dont understand how to get the volume of it

Chemistry
what is the volume of the unit cell? A metal crystallizes in a face-centered cubic lattice. The radius of the atom is 0.197 nm. The density of the element is 1.54 g/cm^3

Chemistry
NaCl crystallizes in face-centered cubic cell. what is the total number of ions(Na+ ions and Cr- ions) that lie withing a unit cell of NaCl? 2 4 8 6 5

Chemistry
What portion of the volume of each atom or ion on the face of a unit cell is actually within the unit cell 1/2 1/4 3/4 all of it none of it

Chemistry
The unit cell with all sides the same length and all angles equal to 90 degrees that has lattice points only at the corners is called monoclinic body-centered cubic primative cubic face-centered cubic spherical cubic

Chemistry
Determine the mass of the element? what element is it? Ca Ag Ti Mg Al

Chemistry
what is the molar volume of the metal in cubic centimeters(avogadro's number should be used for this problem -1cm=10^7 nm)

Chemistry
what is the volume of the unit cell

Chemistry
What mass of solution containing 6.50% sodium sulfate N2SO4 by mass contains 1.50g Na2SO4

Chemistry
How would you prepare 455 g of aqueous solution that is 6.50% sodium sulfate Na2SO4 by mass?

Chemistry
Indicate which is more soluble in ethanol? C2H5OH, acetic acid, CH3COOH, or stearic acid C17H35COOH.

Chemistry
People have proposed towing icebergs to arid parts of the earth as a way to deliver freshwater. Explain why icebergs do not contain salts although they are formed by the freezing of ocean water (i.e saltwater)

Chemistry
A tank of gas at 21 degrees C has a pressure of 1.0 atm. Using the data in the table answer the following questions. Explain your answers A. If the tank contains carbon tetrafluoride, CF4 is the liquid state also present? B. If the tank contains butane, C4H10 is the liquid sta...

Chemistry
A quantity of ice at 0.0 degrees C was added to 33.6 of water at 21.0 degree C to give water at 0.0 degrees C. How much ice was added? The heat of fusion of water is 6.01 kJ/mol and the specific heat is 4.18 J/(g * degrees C) q = mass x specific heat x delta T? q = mass x heat...

Chemistry
A quantity of ice at 0.0 degrees C was added to 33.6 of water at 21.0 degree C to give water at 0.0 degrees C. How much ice was added? The heat of fusion of water is 6.01 kJ/mol and the specific heat is 4.18 J/(g * degrees C) q = mass x specific heat x delta T? q = mass x heat...

Chemistry
Methanol, CH3OH a colorless voltile liquid was formerly known as wood alcohol. It boils at 65 degrees C and has a heat of vaporization of 37.4 kJ/mol. What is its vapor pressure at 22.0 degrees C?

algebra
-8+3 = -5 x-5<11 +5 +5 X< 16

Chemistry
Snow forms in the upper atmosphere in a cold aid mass that is supersatuated with water vapor. When the snow later falls through a lower, warm air mass, rain forms. When atomic weight is 63.5 amu. Calculate the edge length of the unit cell.

Chemistry
On the basis of the description given classify each of the following solids as molecular, metallic, ionic, or covalent network. Explain why? A. a lustrous, yellow solid that conducts electricity B. a hard, black solid melting at 2350 degrees C to give a nonconducting liquid C....

Chemistry
well all it asks is name the types of solid it forms and those four our the types of solids. so like LiCl you said it was an ionic compound so it might be ab ionic solid and so on

Chemistry
Classify each of the following by the type of solid if forms: a. LiCl b. BaCl2 c. BCl3 d. CCl4 e. NCl3 I have four different types of solids to guess from like Metallic solid, ionic solid, molecular solid, covalent network solid and i dont know which goes with what element

Chemistry
Describe the formation of hydrogen bonds in a hydrogen peroxide, H2O2. Represent possible hydrogen bonding structures in hydrogen peroxide by using structural formulas and the conventional notation for a hydrogen bond.

Chemistry
Snow forms in the upper atmosphere in a cold aid mass that is supersatuated with water vapor. When the snow later falls through a lower, warm air mass, rain forms. When atomic weight is 63.5 amu. Calculate the edge length of the unit cell.

Chemistry
On the basis of the description given classify each of the following solids as molecular, metallic, ionic, or covalent network. Explain why? A. a lustrous, yellow solid that conducts electricity B. a hard, black solid melting at 2350 degrees C to give a nonconducting liquid C....

Chemistry
Sorry I clicked to fast but that is the question and I have four different types of solids to guess from Like Metallic solid, ionic solid, molecular solid, covalent network solid and i dont know which goes with what element

Chemistry
Which of the following do you expect to be molecular solids? A. sodium hydroxide NaOH B. Solid Ethane C2H6 C. Nickel, Ni D. Solid Silane SiH4

Chemistry
I didnt write I cant find it someone else did being stupid and putting my name down as a reply

Chemistry
Can't find it.

Chemistry
Classify each of the following by the type of solid if forms: a. LiCl b. BaCl2 c. BCl3 d. CCl4 e. NCl3

Chemistry
Predict the order of increasing vapor pressure at a given temperature for the following compounds: CH3CH2CH2CH2OH HOCH2CH2CH2OH CH3CH2OCH2CH3

Chemistry
which of the following compounds would you expect to exhibit only London forces? CCL4 CCLH CaI2 PCl5

Chemistry
A tank of gas at 21 degrees C has a pressure of 1.0 atm. Using the data in the table answer the following questions. Explain your answers A. If the tank contains carbon tetrafluoride, CF4 is the liquid state also present? B. If the tank contains butane, C4H10 is the liquid sta...

Chemistry
Methanol, CH3OH a colorless, volatile liquid was formely known as wood alcohol. It boils at 65.0 degrees C and has a heat vaporization of 37.4 kJ/mol. What is its vapor pressure at 22.0 degrees C ?

Chemistry
A quantity of ice at 0.0 degrees C was added to 33.6 of water at 21.0 degree C to give water at 0.0 degrees C. How much ice was added? The heat of fusion of water is 6.01 kJ/mol and the specific heat is 4.18 J/(g * degrees C)

Chemistry
Liquid Butane, C4H10, is stored in cylinders to be used as a fuel. Suppose 39.3g of butane gas is removed from a cylinder. How much heat must be provided to vaporize this much gas? The heat of vaporization of butane is 21.3 kJ/mol.

Chemistry
Liquid Butane, C4H10, is stored in cylinders to be used as a fuel. Suppose 39.3g of butane gas is removed from a cylinder. How much heat must be provided to vaporize this much gas? The heat of vaporization of butane is 21.3 kJ/mol.

Chemistry
A 35.8f sample of cadminum metal was melted by an electric heater 4.66 J/s of heat. If it took 6.92 min from the time the metal began to melt until it was completely melted, what is the heat of fusion per mole of cadminum?

Business
In a world without trade, what would American consumers have to pay for logitech's products?

Chemistry
Phase diagrams- Explain how the density of the solid and liquid phase would compare.

Chemistry
I think this might be right...adjusting the volume for temperature. 273K + 23K= 296K The two possible temperature ratio would be 296K/273K or 273K/296K. I chose the second one. 57.6 ml(273K)/296K answer: 53.1 ml

Chemistry
A eudiometer contains 65.0 ml sample of gas collected by the diplacement of water. The water levels inside and outside the eudiometer are the same. The atmospheric pressure is 92.5 kPa and the temperture is 23 degrees. What volume will the dry gas occupy at STP? The vapor pres...

Chemistry
A pocket of gas is discovered in a deep drilling operation. The gas has a temperature of 480c and is at a pressure of 12.8 atm. What volume of gas is required to provide 18.0 L of gas at the surface where the conditions are 22 C and 1.00 atm?

Chemistry
Answer check: Define a catalyst and explain a catalyst's role in a chemical reaction. A catalyst is a substance that speeds a chemical reaction without being permanently changed itself. It works by providing a convenient surface for the reaction to occur. The reacting part...

English
Hi, I need to know the background on the literay term: interjection. I have the definition and examples of it, but I can't seem to find any history on it. Help would be appreciated. Thank you so much!

Chemistry
Which if the following compounds is insoluble in water (NH4)2CO3 AgBr CuSO4 KI LiNO3 is it CuSO4 because sulfates are insolube

Chemistry
to lead nitrate because it is solube

Chemistry
a precipitate is expected when an aqueous solution of potassium iodide is added to an aqueous solution of: sodium sulfate iron(II) chloride calcium perchlorate barium hydroxide lead nitrate

Science
Explain Why A Hot Air Balloon Rises

Chemistry
Which if the following compounds is insoluble in water (NH4)2CO3 AgBr CuSO4 KI LiNO3 I thought it might be AgBr

Chemistry
When an aqueous solution of lithium chloride is mixed with an aqueous solution of ammonium sulfate a precipitate forms a new salt is formed a gas is evolved an acid and base are formed no reaction occurs I either thought it was a precipitate forms or no reaction occurs

Chemistry
All of the following are weak acids except HF H3PO4 H2SO4 HNO2 HC2H3O2

Chemistry
Which of the following is a weak base HOCl LiOH Ba(OH)2 KOH NH3

Chemistry
Which of the following indicates the exsistence of stron intermolecular forces of attraction in a liquid? a very low boiling point a very low vapor pressure a very low critical pressure a very low viscosity a very low heat of vaporization

Chemistry
Which of the following molecules has polar bonds and is nonpolar? HF ICI3 NF3 SF4 BF3

Chemistry
How do you make CIF2 into a Lewis Structure

Chemistry
Can you tell me if i did these right?? Lewis Dot Structure A. BrF = 5 dots around Br-F with 5 dots around it B. PBr3 = ? I dont know how to do because of the 3 C. NOF= 3 dots around N 2 dots around O and 5 dots around F N-O-F D. CO = 3 dots around C double bond between O and 4...

Chemistry
i dont know what the resonance description is so i dont have anything yet

Chemistry
write the resonance desription for the following A. ClNO2 B. NO-2

Chemistry
Decide which of the following bonds is least polar on the basis of electronegativities of atoms, H---S, Si---Cl, N---Cl.

Chemistry
nevermind i got it

Chemistry
Use Lewis Symbols to show the reaction of atoms to form arsine, AsH3. Indicate bonding pairs in the Lewis formula of AsH3 are bonding and which are lone pairs.

Math
How do I do a tree diagram to find the least common multiple

Chemistry
The principal quantum number of the valence electrons in an atom of lead is: A. 2 B. 3 C. 4 D. 5 E. 6

Chemistry
Which of the following elements has the smallest ionization energy? A. F B. Be C. B D. Mg E. C

Chemistry
How many valence electrons does phosphourous have

Chemistry
The maximum number of electrons that can be accomodated in a p subshell is A.2 B.4 C.6 D. 8 E. 10

Chemistry
The principal quantum number of the valence electrons in a atom of lead is A. 2 B. 3 C. 4 D. 5 E. 6

Chemistry
All of the following are true EXCEPT; A. the n=4 energy level has no f orbitals B. the 2p orbitals can have a maximum if 6 electrons C. the s orbital has a spherical shape D. there are 5 orbitals in a set E. the n=3 energy level has a set of d orbitals.

Chemistry
so I did 1 divided by 4797297.498 and got 2.085 X 10^-7

Chemistry
so i got 1/4797297.498

Chemistry
okay so it should look like this 1/lambda= 1.0967758341 x 10^7(3^2)*[(1/3^2)-(1/4^2)] 1.0967758341 x 10^7(9)(.0486) i got 4798394.274

Chemistry
What is the wavelength of the transition from n=4 to n=3 for Li2+? In what region of the spectrum does this emission occur? Li2+ is a hydrogen-like ion. Such an ion has a nucleus of charge +Ze and a single electron outside this nucleus. The energy levels of the ion are -Z^2RH/...

Chemistry
Help needed for writing up a balance chemical equation for an acid/base titration: for an extended experimental experiment we tested the total acid content of orange juice, then had to write the balanced chemical equation for the experiment to do further calculations but i am ...

Chem
so am I solving for Rh This is what the equation should look like right: 1/9= Rh (1/2)-(1/3)

Chem
What is the wavelength of the transition from n=4 to n=3 for Li2+? In what region of the spectrum does this emission occur? Li2+ is a hydrogen-like ion. Such an ion has a nucleus of charge +Ze and a single electron outside this nucleus. The energy levels of the ion are -Z^2RH/...

Chemistry
What is the wavelength of the transition from n=4 to n=3 for Li2+? In what region of the spectrum does this emission occur? Li2+ is a hydrogen-like ion. Such an ion has a nucleus of charge +Ze and a single electron outside this nucleus. The energy levels of the ion are -Z^2RH/...

Chem
Thank you

Chem
well 9.98 X 10^11 / 3.00 x 10^8 = 3326.66

Chem
yes as you can see i put them in the answer i just dint type them out

Chem
9.98 X 10^11m = 3.00 X 10^8m/s (time) so I converted 998 million km into m now I divided 9.98/ 3.00 and got 3.33 x 10^19 is this correct

Chem
So rate is the speed of light too

Chem
The space probe Pioneer 11 was launched April 5,1973, and reached Jupiter in December 1974 traveling a distance of 998 million km. How long did it take an electromagnectic signal to travel to earth from Pioneer 11 when it was near Jupiter. The speed of light is, for all practi...

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