Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

Chemistry
Ammonium ion (NH4^+) reacts with nitrite ion (NO2^-) to yield nitrogen gas and liquid water. The following initial rates of reaction have been measured for the given reactant concentrations. Expt. # [NH4^+] [NO2^-] Initial rate (M/hr) 1 0.010 0.020 0.020 2 0.015 0.020 0.030 3...
Wednesday, February 6, 2013 at 7:04pm

Organic chemistry
A diels-Alder reaction of cyclopentadiene with Maleic Anhydride experiment was conducted in lab. But I was wondering why we added ligroin to the maleic anhydride and ethyl acetate. I know ligroin can be used as a solvent and it is also nonpolar, though ethyl acetate is also a ...
Wednesday, February 6, 2013 at 6:49pm

Chemistry
4Fe + 3O2 -> 2Fe2O3 + 1.65E3 kJ C) what is the enthalpy change for the formation of 23.6 g of iron(iii) oxide? I'm trying to understand thermochemical reactions and stoichiometry, so could you please tell me if this is correct? And please explain the parts that I ...
Wednesday, February 6, 2013 at 6:45pm

CHEMISTRY
In PCl5, Fe2S3, H3PO4, how many number of a.)elements b.)atoms c.)molecules are present?? Is it pure? Is it a compound or a mixture??
Wednesday, February 6, 2013 at 6:36pm

Chemistry
The formula for ibuprofen is C13H18O2. How many moles of ibuprofen are present in a 200.0mg tablet.
Wednesday, February 6, 2013 at 5:54pm

Chemistry
Calculate the mass of each element in Na2CO3
Wednesday, February 6, 2013 at 5:52pm

Chemistry
The following initial rate data apply to the reaction F2(g) + 2Cl2O(g) ----> 2FClO2(g) + Cl2(g) Expt. # [F2](M) [Cl2O](M) Initial rate (M/s) 1 0.05 0.010 5.0 x 10^–4 2 0.05 0.040 2.0 x 10^–3 3 0.10 0.010 1.0 x 10^–3 Which of the following is the rate law (...
Wednesday, February 6, 2013 at 5:46pm

Chemistry
What is the concentration of methanol in a solution prepared by combining 7.85mL of a 3.693M methanol solution with 17.50mL of water? Assume volumes are additive and report your answer to 3 decimal places.
Wednesday, February 6, 2013 at 5:29pm

Organic Chemistry
So im trying to make 1-acetylcyclohexane from ethenylcyclohexane..and i have to make it in 4 stepsi got the first two steps but the last two is what i am unsure of.. 1) Br2 2) 2 equiv NaNH2 3) ?? 4) ?? i know the 1st two steps but im having trouble figuring out the last two ...
Wednesday, February 6, 2013 at 4:42pm

Chemistry
This isn't exactly a homework question, I'm just trying to understand the concept we learned today... So say we had: 4Fe + 3O2 → 2Fe2O3 + 1.65 x 10^3 kJ Does that mean for every 4 mol of Fe, 3 mol of O2, and 2 mol of Fe2O3 we have 1.65 x 10^3 kJ? And if I were to...
Wednesday, February 6, 2013 at 4:39pm

chemistry
The charge and identity of an ion with 16 protons, 18 electrons and 17 neutrons would be?
Wednesday, February 6, 2013 at 3:49pm

chemistry
is the osmotic pressure formed by dissolving 50.9 mg of aspirin (C9H8O4) in 0.450 L of water at 24°C
Wednesday, February 6, 2013 at 3:42pm

Chemistry
N2 + O2 -> 2NO enthalpy change = +180.6kJ c) what is the enthalpy change for the formation of one mole of nitrogen monoxide? Okay, I know this question is super easy, but I don't know how to do it; if someone could please give me a detailed explaination on how to do a ...
Wednesday, February 6, 2013 at 3:27pm

Chemistry
Hg + I2 -> HgI2 Whats the mass of HgI2 if you have 0.7236g mercury and 0.3264g iodine?
Wednesday, February 6, 2013 at 3:26pm

Chemistry
Solution of 50g AgNO3 is mixed with 50g NaCl. a) What mass of AgCl will you get? b) which substance is in redundancy?
Wednesday, February 6, 2013 at 3:21pm

Chemistry
Whats the percent yield in the reaction: P+5C2H5OH+ 5/2 I2 -> 5C2H5I + H3PO4 + H2O if you have 4.14g phosporous, 27.5g ethanol, 63.5g iodine, and you get 73g ethyliodine (C2H5I)
Wednesday, February 6, 2013 at 3:19pm

chemistry
If 2.25g of a gas occupies 1750mL at 180 degrees Celsius and 550mm Hg of pressure, what is the molecular weight of the gas?
Wednesday, February 6, 2013 at 2:14pm

Chemistry
The heat lost or gained by a system is related to its temperature change by a property called its heat capacity. The molar heat capacity of metals at or above room temperature equals 24.92 J K-1mol-1. The temperature of a block of copper metal (molar mass 63.55 g mol-1) fell ...
Wednesday, February 6, 2013 at 12:40pm

GEneral Chemistry
the radius of a chlorine atom is 99 pm and its mass is 5.89 X 10^-23 grams what is the density When I look at this i know that 99pm= 9.9e-7 and to get volume v=(3/4) or 1.33 (3/4)*3.14- pi *r^3 When I get to this point I do: 1.33*3.14= 4.1762*9.9e-7= 4.1e-6pm convert 4.1e-6pm ...
Wednesday, February 6, 2013 at 12:16pm

Analytical chemistry
A 0.6334 gram of sample of impure mercury (II) oxide was dissolved in an unmeasured excess of potassium iodide. Reaction: HgO + 4I- + H2O ------→HgI42- + 2OH- Calculate the % HgO in the sample if titration of the liberated hydroxide required 42.59 ml of 0.1178 M HCl.
Wednesday, February 6, 2013 at 10:09am

chemistry
1oocm3 of 0.1mhcl as to be prepared from 2mhcl, how much of the stalk is required
Wednesday, February 6, 2013 at 7:43am

General Chemistry
When calcium carbonate is added to hydrochloric acid, calcium chloride, carbon dioxide, and water are produced. CaCO3(s)+2HCl(aq)--> CaCl2(aq)+H2O (l)+CO2(g) How many grams of calcium chloride will be produced when 32.0 g of calcium carbonate are combined with 11.0 g of ...
Wednesday, February 6, 2013 at 6:06am

general chemistry
A 1.24g sample of a hydrocarbon, when completely burned in excess of O2(g), yields 4.04g CO2 and 1.24g H20. Determine the empirical formula.
Wednesday, February 6, 2013 at 3:44am

Organic chemistry
We conducted a diels-Alder reaction of cyclopentadiene with Maleic Anhydride experiment. Though I was wondering why we added ligroin to the maleic anhydride and ethyl acetate. I know ligroin can be used as a solvent, but I thought that ethyl acetate was the solvent in this ...
Wednesday, February 6, 2013 at 3:26am

Chemistry
What mass of Iodine contains same number of atoms as 50.0g of Cl?
Wednesday, February 6, 2013 at 3:15am

general chemistry
the radius of a chlorine atom is 99 pm and its mass is 5.89 X 10^-23 grams what is the density
Wednesday, February 6, 2013 at 2:56am

chemistry
what possible chemicals can test the presence of limonene except bromine water and potassium permanganate?
Wednesday, February 6, 2013 at 2:21am

chemistry
newton 1st law of motion
Wednesday, February 6, 2013 at 2:19am

chemistry/physics
If a rock climber accidentally drops a 69.0 g piton from a height of 305 meters, what would its speed be just before striking the ground? Ignore the effects of air resistance.
Wednesday, February 6, 2013 at 12:10am

Chemistry
One medium bran muffin connateness 4.2 g of fiber. How many ounces of fiber are obtained by eating three medium bran muffins? I need help understanding the conversion factor process
Tuesday, February 5, 2013 at 11:53pm

Chemistry
In which direction will the net reaction proceed X(g)+Y(g)<---->Z(g) Kp=1.00 at 300k for each of these sets of initial conditions? a) [X]=[Y]=[Z]=1.0 m net reaction goes to the left net reaction goes to the right reaction is at equilibrium I chose 3 for a. b) Px=Pz=1.0 ...
Tuesday, February 5, 2013 at 10:57pm

Chemistry
4.00 mol of solid A was placed in a sealed 1.00-L container and allowed to decompose into gaseous B and C. The concentration of B steadily increased until it reached 1.20 M, where it remained constant. A(s) <-------> B(g)+C(g) Then, the container volume was doubled and ...
Tuesday, February 5, 2013 at 10:56pm

Chemistry
A chemical procedure calls for 3.54mol of dry ice (solid CO2). What mass of CO2 should we add?
Tuesday, February 5, 2013 at 10:31pm

Chemistry
What mass of iodine contains the same number of atoms as 50.0g of chlorine?
Tuesday, February 5, 2013 at 10:29pm

Chemistry
How come the formula for potassium peroxide is K2O2; I can't see how you'd get that...
Tuesday, February 5, 2013 at 10:28pm

Chemistry
A mole of a pure substance contains 6.02x10^23 atoms. Alway true, sometime true or never true? -I was thinking sometime true since a pure substance can be like H2O but H2O have 3 "atoms" (Is this what you call individual part of H2O?). Each "atoms" have 6....
Tuesday, February 5, 2013 at 6:32pm

Chemistry
Why is the formula for potassium peroxide K2O2?
Tuesday, February 5, 2013 at 6:07pm

Chemistry (Combustion) formula question
Data; Volume of water, 100ml Room temp, 24C Initial water temp, 15C Final water temp, 30C Question: Calculate the mass of water heated. Hint: The density of the liquid water is 1.0g/ml. I have no idea how to do this. Can someone help? Thanks!
Tuesday, February 5, 2013 at 4:26pm

chemistry
I am supposed to add NH4 and C2H3O2 together and write the new ion. Would it be NH7C2O2? do I add the hydrogens together and were would it go in the order then?
Tuesday, February 5, 2013 at 2:57pm

Chemistry(the)
An optically active compound having molecular formula C6H12O6 is found in two isomeric forms (A) and (B) in nature. When (A) and (B) are dissolved in water they show the following equilibrium. (A) Equilibrium mixture (B) D = 1110 52.20 19.20 (i) What are such isomers called? (...
Tuesday, February 5, 2013 at 12:22pm

Chemistry
1) given the following equation : Na2O 2Hl__>2Nal H2O (501.6KJ) a) 1f 9g of Nal are formed by the process, how much heat(q)will be involved? b) state whether the reaction is endorthermicor exothermic
Tuesday, February 5, 2013 at 12:10pm

Chemistry
a .50 g of NaCl is added to water to create a .50 L solution. what volume of this solution is needed to create a 1.30L solution that is .100M NaCl
Tuesday, February 5, 2013 at 10:36am

Chemistry
Calculate the final temperature of 244 of water initially at 35 upon absorption of 20 of heat
Tuesday, February 5, 2013 at 9:27am

chemistry
what would be the volume of 0.05 mole of carbon tetra chloride gas ccl4 ar rtp
Tuesday, February 5, 2013 at 5:59am

chemistry
would the ratio of moles of Cu:moles of CuCl2 differ from atoms of Cu:formula units of CuCl2? Why or Why not?
Tuesday, February 5, 2013 at 12:11am

Chemistry
You decide to establish a new temperature scale on which the melting point of ammonia (-77.75 C ) is 0 A, and the boiling point of ammonia (-33.35 C ) is 200 A What would be the temperature of absolute zero in A ?
Monday, February 4, 2013 at 9:29pm

Chemistry
if we mix 25 grams of sodium bromide with a large amount of potassium chloride, what will our theoretical yield of sodium chloride be?
Monday, February 4, 2013 at 9:24pm

chemistry
What is the relationship between mass number,atomic number and of neutron and Give examples
Monday, February 4, 2013 at 9:03pm

chemistry
Give the balance chemical reaction from the following decays.(a) loss of B^+ by ^15,8 O (b) loss of B^- by ^Ag (c) loss of * by ^46,62Sn
Monday, February 4, 2013 at 8:58pm

Chemistry 12
The complete combustion of 1.00mL of octane increases the temperature of 250.00g of water by 22.7 degrees Celsius. The density of octane is 0.70g/mL. What is the efficiency of the octane in heating the water? I attempted this question and I have -400 something percent ...
Monday, February 4, 2013 at 7:05pm

chemistry
when 2.31 moles of sulfur hexafluoride are synthesized from te elements, how many grams of fluorine were used
Monday, February 4, 2013 at 6:38pm

Chemistry
The metal palladium crystallizes in a face-centered cubic lattice with an edge length of 388.8 pm. What is the density of the palladium?
Monday, February 4, 2013 at 6:32pm

Chemistry
What is the value of q when 8.21g of water vaporizes at 373 K? The enthalpy of condensation of water at 373 K is -40.7 kJ/mol. I tried using the equation q= m x Cs x Delta T, but I never got the right answer which is 18.5 kJ apparently, so I need to find out what I did wrong.
Monday, February 4, 2013 at 6:29pm

Chemistry
The complete combustion of 1.00 ml of octane increases the temperature by 22.7 degrees celsius. The density of octane is 0.7g/mL. What is the efficiency of the octane in heating the water?
Monday, February 4, 2013 at 6:07pm

chemistry
a 0.25 mol sample af neon gas at 18 C and 0.700 atm is heated to 40 C. the new gas pressure is 1.11 atm. what is the change in volumn of the neon gas?
Monday, February 4, 2013 at 4:38pm

Chemistry
you have 57.0 mL of a 2.00 M stock solution that must be diluted to 0.500 M. how much water should you add?
Monday, February 4, 2013 at 3:52pm

Chemistry
This is question 4a on section a.12 chemistry. What will you observe happening to the balloon as it sits in the warm car
Monday, February 4, 2013 at 3:18pm

Chemistry
you have 57.0 mL of a 2.00 M stock solution that must be diluted to 0.500 M. how much water should you add?
Monday, February 4, 2013 at 2:42pm

Chemistry
What is the activity coefficient of H^+ in a solution containing 0.073 M HCl and 0.0090 M Ca(ClO4)2? What is the pH of the solution? I believe I have to find the ionic strength of the solution first, but I don't know how to find it when 2 solutions are involved.
Monday, February 4, 2013 at 2:41pm

Chemistry
you have 57.0 mL of a 2.00 M stock solution that must be diluted to 0.500 M. how much water should you add?
Monday, February 4, 2013 at 2:35pm

Chemistry
you have 57.0 mL of a 2.00 M stock solution that must be diluted to 0.500 M. how much water should you add?
Monday, February 4, 2013 at 2:27pm

Chemistry
you have 57.0 mL of a 2.00 M stock solution that must be diluted to 0.500 M. how much water should you add?
Monday, February 4, 2013 at 2:24pm

Chemistry
Complete the charge balance equation for an aqueous solution of H2CO3 that ionizes to HCO3^- and CO3^2- ______ = ______ + _______ + _______ Given choices: [HCO3^-],[CO3^2-], [OH^-], 2[H^+], [H2CO3], 2[CO3^2-], 3[H^+], {H^+] I don't understand how to do charge balance :(
Monday, February 4, 2013 at 2:09pm

Chemistry
Find the Concentration of CrO4^2- in 0.0033M Ba(NO3)2 saturated with BaCrO4. Include activity coefficients in your solubility-product expression. Ksp of BaCrO4 = 1.17 x 10^-10 I have no idea what to do to solve this :(
Monday, February 4, 2013 at 2:03pm

chemistry
ionic and net ionic equation for sodium carbonate and potassium chloride
Monday, February 4, 2013 at 1:17pm

chemistry
net ionic equation for KI+Na2So2O3+KCl
Monday, February 4, 2013 at 12:44pm

college chemistry
How many grams would you weigh out to get 3.1 X 10-3 Moles of MgCl2?
Monday, February 4, 2013 at 12:26pm

chemistry
A fixed mass of gas has a volume of 440cm3 at 13degree cetigrate and 836mmhg.calculate its volume at s.t.p.
Monday, February 4, 2013 at 3:48am

chemistry
For the reaction below, KP = 1.6 × 106 at 400.0 °C. HCHO2( g ) <--> CO( g ) + H2O( g ) A mixture of CO( g ) and H2O(l ) was prepared in a 2.00 L reaction vessel at 25 °C in which the pressure of CO was 0.177 atm. The mixture also contained 0.391 g of H2O. ...
Monday, February 4, 2013 at 12:47am

chemistry
The nuclear reaction Sn ¨ Sb + ? is an example of
Monday, February 4, 2013 at 12:16am

Chemistry
Fe 3+ + scn- + Na2PHO4 produces what exactly?
Monday, February 4, 2013 at 12:08am

chemistry
An object has a KE= 18000 and a massof 98kg what is the speed of the object
Sunday, February 3, 2013 at 11:54pm

chemistry
how many grams of lithium bromide are in 0.79 mol.of lithium bromide?
Sunday, February 3, 2013 at 8:14pm

Chemistry
Hi, Just have follow up questions to the previous questions asked dating Feb. 02, 2013 1. So the overall idea is that dissociation decreases molar mass and association does the opposite when a solute dissolves in a solvent. (How do you identify if either reaction occurs? Just ...
Sunday, February 3, 2013 at 6:29pm

chemistry
can u tell me whats the most imprtant subject i need to know for molecular composition of gases ? and for physical characteristics of gases?
Sunday, February 3, 2013 at 6:16pm

chemistry
80ml of hcl is added to 2.5gm of pure cac03 when the reaction is over, then 0.5gm cac03 is left. Find the normality of the acid The answer 0.5N Who helps step by step
Sunday, February 3, 2013 at 6:10pm

Chemistry
How many moles of H atoms are there in 21.66 g of Mg(OH)2? What is the mass of F (in g) in 8.03 x 1023 BF3 molecules
Sunday, February 3, 2013 at 5:59pm

Chemistry
If 25 grams of copper(II) sulfate pentahydrate were heated until all water was removed, how much residue would remain?- Could someone help me understand this question? I don't understand it at all. Thanks
Sunday, February 3, 2013 at 5:28pm

CHEMISTRY URGENT!
a sample of oxygen that occupies 1.00 x 10^6mL at 575mmHg is subjected to a pressure of 1025atm. what will the final volume of the sample be if the temperature is held constant? how do uu set up the equation
Sunday, February 3, 2013 at 5:12pm

Chemistry
Is there a chemical formula for animal fats? - Would the lipids chemical formula be the same as animal fats? Thanks
Sunday, February 3, 2013 at 5:03pm

Chemistry
How many moles of OCl2 contain 38.42 g of Cl? Answer
Sunday, February 3, 2013 at 4:48pm

Chemistry
I did a lab that involve cooking meat and finding the mass of lipids, meat tissue and water. For a chicken sample the original mass was 20 gram. After cooking there was 15.5g of meat, and 1.5 g of oil, and 1 g of water. I am missing 2 g of the original mass. Anyone have any ...
Sunday, February 3, 2013 at 4:43pm

Chemistry
For the reaction of hydrazine (N2H4) in water, Kb is 3.0 10-6. H2NNH2(aq) + H2O(l)--> H2NNH3+(aq) + OH-(aq) Calculate the concentrations of all species and the pH of a 1.6 M solution of hydrazine in water. [OH-] = [H2NNH3+] = [H2NNH2] = [H+] = pH =
Sunday, February 3, 2013 at 4:26pm

chemistry
For the reaction below, Kp = 1.16 at 800.°C. CaCO3(s) CaO(s) + CO2(g) If a 21.7-g sample of CaCO3 is put into a 10.6 L container and heated to 800°C, what percentage by mass of the CaCO3 will react to reach equilibrium?
Sunday, February 3, 2013 at 3:18pm

chemistry
How much heat (in cal) is necessary to heat 27.0 mL of octane (s= 0.526 cal/g ®C ; d = o.703 g/mL ) from 50.6 ®C to 67.2 ®C? I understand the Delta T is = 16.6®C But I don’t know what d stands for (density) or how to apply to the formula.
Sunday, February 3, 2013 at 2:06pm

CHEMISTRY URGENT!
assume that 13.5g of AL react with HCl according to the following equation, at STP: Al(s) + HCl(aq) ---> AlCl3 + H2(g) Remember to balance the equation first. a. how many moles of Al react? b. how mang moles of H2 are produced? c. how mang liters of H2 at STP are produced? ...
Sunday, February 3, 2013 at 2:02pm

chemistry
i have some question but i can not post it ,what should i do .help
Sunday, February 3, 2013 at 12:06pm

Chemistry
The air we inhale contains O2 we exhale CO2 and H2O does this suggest that our bodily processes invove oxidation? Why?
Sunday, February 3, 2013 at 11:49am

analytical chemistry
In an experiment for determining water hardness, 75.00 ml of a water sample required 13.03 ml of an EDTA solution that is 0.009242 M. What is the ppm CaCO3 in this sample? Could someone please tell me if this is correct? Total hardness, ppm CaCO3 = mg CaCO3 / L = 13.03 ml x 1....
Sunday, February 3, 2013 at 11:45am

chemistry
1.00 g zinc and 0.80 g sulfur are allowed to react all the zinc is used up 1.50 g of zinc sulfide is formed and some unreacted sulfur remains what is the mass of unreacted sulfur
Sunday, February 3, 2013 at 11:29am

Chemistry
What is a Balanced equation for sulfur (IV) oxide (g) and magnesium oxide (cr)?
Sunday, February 3, 2013 at 11:27am

analytical chemistry
An EDTA solution is standardized against a solution of primary standard CaCO3 (0.5622 g dissolve in 1000 ml of solution) and titrating aliquots of it with the EDTA. If a 25.00 ml aliquot required 21.88 ml of the EDTA, what is the concentration of the EDTA?
Sunday, February 3, 2013 at 8:26am

Chemistry
How to make 10% nitric acid? wouldnt it be 10 mL nitric acid + 100 mL of solvent, making it 10%? What molarity is used it to make 10% nitric acid?
Sunday, February 3, 2013 at 6:17am

organic chemistry
how do I to draw cyclopropane of bond rotation?
Sunday, February 3, 2013 at 12:30am

chemistry
Write the formula of the conjugate acid of base HCO3-,HPO2-,PO43-,SO32-
Saturday, February 2, 2013 at 11:53pm

chemistry
Classify each of the follow species as bronsted lowry acid or base NH3,NCN
Saturday, February 2, 2013 at 11:41pm

Chemistry
Freezing point of pure water = -2, Freezing point of Unknown solution = -1 Mass of unknown in 50g of water = 1.9964g. Calculate the delta T for the solution of the unknown solid and determine the molecular weight of the unknown solid.
Saturday, February 2, 2013 at 11:39pm

chemistry
how many grams of magnesium are required to react with 2.0 moles of hydrochloric acid?
Saturday, February 2, 2013 at 10:28pm

college general chemistry
Calculate the volume of a rectangular solid with a thickness of 0.750 cm and an area of 8.25 cm2
Saturday, February 2, 2013 at 10:22pm

Chemistry
You have a 100mL cylinder containing 40mL of water. A cube measures 2cm on each side is lowered into the cylinder. What is the new volume reading of the cylinder?
Saturday, February 2, 2013 at 10:08pm

Chemistry
Can someone pls help me!! You decide to establish a new temperature scale on which the melting point of ammonia (-77.75 C ) is 0 A, and the boiling point of ammonia (-33.35 C ) is 200 A. What would be the boiling point of water in A ? What would be the temperature of absolute ...
Saturday, February 2, 2013 at 9:37pm

Chemistry
You decide to establish a new temperature scale on which the melting point of ammonia (-77.75 C ) is 0 A, and the boiling point of ammonia (-33.35 C ) is 200 A. What would be the boiling point of water in A ? What would be the temperature of absolute zero in A ?
Saturday, February 2, 2013 at 5:34pm

chemistry help !!!!!!!!!!!!!!!!
complete the following paragraph relating to the enzyme,b -galactosidase .this enzyme hydrolyses the disaccharide lactose to constituent monosaccharides ,galactose and glucose ,drag and drop the approprite words into the correct space. the enzyme ,B-galactosidase is added to a...
Saturday, February 2, 2013 at 5:11pm

Chemistry
The density of aluminum is . A square piece of aluminum foil, 20.02 on a side is found to weigh 2.573 .What is the thickness of the foil, in millimeters?
Saturday, February 2, 2013 at 4:27pm

Chemistry
A vinegar sample is found to have a density of 1.006 and to contain 4.7 acetic acid by mass.How many grams of acetic acid are present in 3.00 of this vinegar?
Saturday, February 2, 2013 at 4:21pm

Chemistry
54.0 mL of a 1.50 M solution is diluted to a total volume of 258 mL. A 129-mL portion of that solution is diluted by adding 165 mL of water. What is the final concentration?
Saturday, February 2, 2013 at 3:01pm

Chemistry
A gas occupies a volume of 502 cm3 at 20.0 C. What will be its volume at 106 C? I understand that it follows Charles' Law where the correct equation is V1/T1=V2/T2. My teacher expects all units of volume to be converted to Liters and all temperature to Kelvins. Using ...
Saturday, February 2, 2013 at 12:28pm

Chemistry Problem
Consider an ionic compound, MX, composed of generic metal M and generic halogen X. The enthalpy of formation of MX is ÄHf° = –457 kJ/mol. The enthalpy of sublimation of M is ÄHsub = 121 kJ/mol. The ionization energy of M is IE = 433 kJ/mol. The electron ...
Saturday, February 2, 2013 at 1:25am

Chemistry
In the situation that a solute dissolves in a solvent, the solute molecules often dissociate and associate. Studying for exam, not sure how to explain HOW dissociation and association affects the molar mass of the solute in this system. (What is dissociation and association?)
Saturday, February 2, 2013 at 1:01am

Chemistry
In the case of a small amount of your unknown failed to dissolve in the t-butanol, would it effect the molar mass? = Does molarity increase as molar mass increases?
Saturday, February 2, 2013 at 12:40am

Chemistry
You have 1.0 mol of HCL and you want to dilute it to .1 mol. How many mL out of 50 should it take up?
Saturday, February 2, 2013 at 12:35am

Chemistry
At 1 atm, how much energy is required to heat 67.0 g of H2O(s) at –14.0 °C to H2O(g) at 115.0 °C? Please explain, I'm not very good at Chemistry and this problem is giving me a headache. Thank you!
Saturday, February 2, 2013 at 12:00am

To gina
I have deleted your post. PLEASE do not put personal information (names, phone numbers, and that kind of thing) on this site. The Internet is not a safe place for that information. I am sorry you arre having trouble with chemistry; however, you must understand that we don'...
Friday, February 1, 2013 at 9:22pm

chemistry 1B
A sample of gas occupies a volume of 61.2 mL. As it expands, it does 133.9 J of work on its surroundings at a constant pressure of 783 torr. What is the final volume of the gas.
Friday, February 1, 2013 at 8:53pm

Chemistry
At 400°C the reaction H2+I2<->2HI has an equilibrium constant Kp value of 55.5. A mixture of 1 mole of H2 and 1 mole of I2 is placed in a flask and heated to 400°C. Calculate the mole fraction of HI in the mixture of gases when equilibrium reached.
Friday, February 1, 2013 at 6:00pm

Chemistry
Explain the following phenomena in terms of intermolecular forces. Determine the major type of forces between the molecules. a) You can't clean grease off you hand with water only b) Pancake syrup is more dense than olive oil. Please provide the structure of both in your ...
Friday, February 1, 2013 at 5:31pm

ENGLISH, HELP?
In the following sentence, which words should be in quotation marks? Did you read the chapter Chemical Reactions in our science textbook, Understanding Chemistry? A. chapter Chemical Reactions B. Chemical Reactions C. Understanding Chemistry I think the answer is B, as it is a...
Friday, February 1, 2013 at 5:09pm

Chemistry 3A
You want to make the following buffer: 5% glucose, 100 mM tris and 10 mM EDTA in a final voume of 300ml. Your stock solutions are 20% glucose, 1M tris and 0.5M EDTA. The diluent is distilled water. Determine how much of each you will add to make the desired buffer. I know this...
Friday, February 1, 2013 at 4:58pm

Chemistry
I had a 1.094g of mystery Alum. "AB(SO4)c. dH2O" (I assume that that the Alum is KAl(SO4)2-12H2O but we don't know A B c or d, we do know that mass percent of water is 51.9) After processing the alum (Ba(NO3)2 and HNO3 through a gooch crucible) we end up with 1....
Friday, February 1, 2013 at 3:07pm

chemistry
How do you make 300 ml of a 2M solution from a 50 M stock solution?
Friday, February 1, 2013 at 12:17pm

chemistry
how long would it take for 1.50 mol of water at 100C to be converted completely into steam if heat were added at a constant rate of 18.0J/s?
Friday, February 1, 2013 at 11:15am

Chemistry
What weight of solute (M,wt =60) is required to be dissolved in 180gm of water to reduce vapour pressure to 4/5th of pure water?
Friday, February 1, 2013 at 11:11am

Chemistry
Find molality of a solution containing non - volatile solute if its vapour pressure is 2% below the vapour pressure of pure water
Friday, February 1, 2013 at 11:04am

Chemistry
30g of the palm shell were mixed with 15ml H3PO4 and 100ml of distilled water in a 250ml conical flask.The concentration of H3PO4 solution was 2.2M, from question,how to prepare those from ortho phosporic acid (98g/mol).Do help me, is it need to make a stock solution first and...
Friday, February 1, 2013 at 10:26am

chemistry
Calculate the amount of heat required to heat a 3.6{\rm kg} gold bar from 20^\circ {\rm C} to 70^\circ {\rm C}. Specific heat capacity of gold is 0.128 \rm J/g ^\circ C
Friday, February 1, 2013 at 9:58am

chemistry
why NH4+ ion is not strong ligand
Friday, February 1, 2013 at 5:03am

chemistry
The density of water at 30.0 °C is 0.9956 g/mL. If the specific gravity of acetic acid is 0.1040 at 30.0 °C, what is the density of acetic acid at 30.0 °C?
Friday, February 1, 2013 at 1:55am

Chemistry
How do I calculate the joules to heat 17 g of water from 22 degrees C to 78 degrees C?
Thursday, January 31, 2013 at 9:46pm

Chemistry
What volume does 0.25 moles of oxygen gas occupy ar STP?
Thursday, January 31, 2013 at 9:27pm

Chemistry
What is the molar volume of the gas ammonia (NH³) at STP?
Thursday, January 31, 2013 at 9:24pm

Chemistry
I am trying to study for my chem test but I don't get how to answe this question A researcher explores the ideal gas equation. He measures the pressure of a system at different temperatures ( keeping the volume and moles of the gas constant) and creates a plot of P versus ...
Thursday, January 31, 2013 at 9:22pm

chemistry
how many valence electrons does copper (Cu), nickel (Ni), and cobalt (Co) have?
Thursday, January 31, 2013 at 9:19pm

Chemistry
If you have 1 mole of baking soda (NaHCO³), then about how many atoms of oxygen do you have?
Thursday, January 31, 2013 at 9:14pm

Chemistry
For the theoretically perfect reaction 2H² +O²---2H²O if you react 300 molecules pf hydrogen and 200 molecules of oxygen, how many oxygen molecules will you have that do not engage in the reaction? Answer 50, 100, 150, or 200?
Thursday, January 31, 2013 at 8:58pm

chemistry
A gas has a volume of 590mL at a temperature of -55.0C What volume will the gas occupy at 30.0C Can someone help me?
Thursday, January 31, 2013 at 8:45pm

Organic Chemistry
Why is the melting point of a known compound (ex. acetanilide) determined before the melting point of the unknown compound? I think it is to determine if the unknown is a pure substance but I am not sure..I just need to be pointed in the right direction.
Thursday, January 31, 2013 at 6:30pm

science:Chemistry
Find the pH of a solution obtained by mixing 100cm3 of 01MHCl solution with 100cm3 of 0.2M NaOH
Thursday, January 31, 2013 at 5:26pm

Chemistry
Which ligand binds the tightest? Ligand A, with a Kd of 10^-9M Ligand B, with a Kd of 10^-3M Ligand C, with a percent occupancy of 30% at one micromolar Ligand D, with a percent occupancy of 80% at 10 nm
Thursday, January 31, 2013 at 3:45pm

Chemistry
At what temperature will the rate constant for the reaction have the value 6.5×10−3 M/s? (Assume k = 5.4 * 10^-4 M/s-1 at 599K and k = 2.8 * 10^-2 M/s at 683K .)
Thursday, January 31, 2013 at 2:57pm

chemistry
If 145 J of heat energy is applied to 34.47 g of an unknown metal, the temperature increases from 61.0 degree C to 78.5 degrees C. What is the specific heat capacity of the unknown metal?
Thursday, January 31, 2013 at 2:49pm

Chemistry
MIke and Shayne reacted sodium chloride with silver nitrate as indicated in the reaction below: AgNO3(aq) + NaCl(aq) → AgCl (s) + NaNO3 (aq) The actual yield of their silver chloride was 0.365 g. According to their calculations, they should have theoretically obtained 0...
Thursday, January 31, 2013 at 2:43pm

Chemistry
What is the largest amount of H2O in grams that can be formed when 6.10 g of H2 reacts with 6.10 g of O2, based on 2 H2 + O2 = 2 H2O
Thursday, January 31, 2013 at 2:41pm

Chemistry
Calculate the half-life (in s) of a first-order reaction if the concentration of the reactant is 0.0655 M 18.4 s after the reaction starts and is 0.0173 M 41.2 s after the reaction starts. I got 25.6 Suppose the half-life is 23.7 s for a first order reaction and the reactant ...
Thursday, January 31, 2013 at 1:59pm

Chemistry
I am trying to determine which protein (in a given list) will stick most tightly to a cation exchange column at pH 7. I am unsure how to go about solving this.. We are given molecular weight, isoelectic point, and number of subunits for each protein. Where should I begin?
Thursday, January 31, 2013 at 1:47pm

General Chemistry
How many milliliters of 0.5M NaOH must be added to 200 mL of 0.1M NaH2PO4 to make a buffer solution with a pH of 6.9?
Thursday, January 31, 2013 at 11:05am

chemistry
sodium metal dissolves im liquid mercury to form of NA(s) and Hg(l) are 0.97 g/ml and 13.6 g/ml respectively. a sodium amalgoum is made by dissolving 10 ml Na (s) in 20.0 ml Hg (l). The final volume of solution is 21.0 ml. Calculate the molarity of Na in the solution.
Thursday, January 31, 2013 at 9:43am

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