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April 18, 2014

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

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chemistry
IDK
Tuesday, January 28, 2014 at 12:11pm

Chemistry
Methanol is a alcohol with the formula CH3OH. Ethanoic acid is a acid, C2H4O2. And alcohol and Acid form an Ester, and in this case methyethanoate CH3COOCH3 and water.
Tuesday, January 28, 2014 at 11:05am

Chemistry
What is the reaction between methanol and ethanoic acid when heated?
Tuesday, January 28, 2014 at 10:58am

Chemistry Combined Gas Law
combined gas law: p1V1/T1=P2V2/T2 you are looking for V2 V2=P1/P2 * V1*T2/T1 = 760/750 * 10ml*(15+273)/(27+273)
Tuesday, January 28, 2014 at 10:42am

chemistry(balance equation)
2na+2h2o=2naoh+h2
Tuesday, January 28, 2014 at 9:59am

Chemistry Combined Gas Law
Hi so im reviewing or our long test tomorrow on combined gas law and gay lussac's well here, combined gas law i find it (maybe ) confusing to do this one, because theres no right answers because it is a practice exercise.. what i know on combined gas law is that pressure ...
Tuesday, January 28, 2014 at 9:47am

chemistry
I think I would get another professor. Bee venom is acidic as it contains the highly acidic peptide melittin, and these interventions are often recommended to neutralize the venom; however, neutralizing a sting is unlikely to be effective as the venom is injected under the ...
Tuesday, January 28, 2014 at 6:29am

chemistry
By using the method of neutralization the acidity of the bee sting can be neutralized. What is the underlying principle and what are the chemical equations involved.
Tuesday, January 28, 2014 at 2:25am

Chemistry
The freezing point of a .200m solution: -.904 degrees Celsius.
Tuesday, January 28, 2014 at 12:57am

Chemistry
Colligative Properties The freezing point of distilled water was determined by recording a thermogram: -0.176. The freezing point of a 0.200 m (molality) solution containing an unknown, ionic compound was determined by recording a second thermogram. a. Determine the freezing ...
Tuesday, January 28, 2014 at 12:56am

Chemistry
2.44
Monday, January 27, 2014 at 11:43pm

Chemistry
A 1.00% by mass MgSO4 solution has a freezing point of -.192°C. Water has a Kf of 1.86 (KxKg)/mol. a.) Estimate the van’t Hoff i factor from the data. b.)Determine the total molality of all solute species. c.) Calculate the percentage dissociation of MgSO4 in this ...
Monday, January 27, 2014 at 10:24pm

Chemistry
Use the Clausius-Claypeyron equation and solve for delta Hvap.(You know p at 20 and you know p is 760 mm at 74.1.) Then use CC equation a second time and one of the other values to solve for vapor pressure at 277 K (39F). Use PV = nRT and solve for n. Convert n to grams, ...
Monday, January 27, 2014 at 9:48pm

chemistry
Use PV = nRT
Monday, January 27, 2014 at 9:34pm

chemistry
A sample of nitrogen gas is confined in a 8.278 x 10-2 L container at 2.236 x 102 torr and 50 oC. How many moles of gas are present in the sample?
Monday, January 27, 2014 at 9:21pm

Chemistry
Trichloroethane, C2H3Cl3, is the active ingredient in aerosols that claim to stain-proof men's ties. Trichloroethane has a vapor pressure of 100.0 mm Hg at 20.0 C and boils at 74.1 C. An uncovered cup (1/2 pint) of trichloroethane (d=1.325 g/mL) is kept in an 18-ft3 ...
Monday, January 27, 2014 at 9:13pm

Chemistry
Thanksss!!! :D it worked much appreciated!
Monday, January 27, 2014 at 9:01pm

Chemistry
tetraaqooxalatoferrate(III)
Monday, January 27, 2014 at 8:38pm

chemistry
volume = pi*r^2*thickness. density = mass/volume.
Monday, January 27, 2014 at 8:31pm

CHEMISTRY URGENT!!!!
You're answer is in meters. Convert to nm.
Monday, January 27, 2014 at 8:30pm

Chemistry
The formula I gave you gives wavelength in meters. The question asks for nanometers. Make the conversion. 1 m = 10^9 nm.
Monday, January 27, 2014 at 8:29pm

Chemistry
I'm confused. If the question is 10^-2g that is 0.01g = 10 mg. I think 1 tablet will do it although that isn't 10 mg BUT you don't want to overdose.
Monday, January 27, 2014 at 8:27pm

CHEMISTRY URGENT!!!!
An electron transition in a single H-atom from n=3 to n=2 results in the release of a single photon. What is the wavelength of this photon in nanometers? NEED ANSWER CUZ MINE ISNT WORKING
Monday, January 27, 2014 at 8:27pm

Chemistry
I tried that but my answer is 6.56*10^(-7) and when I plug it in the site tells me my answer is wrong what went wrong?
Monday, January 27, 2014 at 8:26pm

chemistry
if a coin with 3.0 cm diameter, 0.2 cm thickness weighs 10.377g, what are its volume and density?
Monday, January 27, 2014 at 8:25pm

Chemistry
1/wavelength = R(1/4 - 1/9) R = 1.0973732E7 The 1/4 is 1/2^2 The 1/9 is 1/3^2
Monday, January 27, 2014 at 8:00pm

Chemistry
trioxalatoferrate(III) I'll work on #1
Monday, January 27, 2014 at 7:55pm

Chemistry
I need help with naming two complex ions 1) [Fe(H2O)4C2O4]+ 2)[Fe(C2O4)3]3-
Monday, January 27, 2014 at 7:09pm

Chemistry
An electron transition in a single H-atom from n=3 to n=2 results in the release of a single photon. What is the wavelength of this photon in nanometers? How do I solve this?
Monday, January 27, 2014 at 7:06pm

Chemistry
Also this please- The specific gravity of a vegetable oil is 0.85. What is its density? How do I figure it out?
Monday, January 27, 2014 at 6:05pm

Chemistry
it's 10^-2g
Monday, January 27, 2014 at 5:54pm

Chemistry
1.A patient needs 2.10×10−2g of a sulfa drug. There are 8.00mg tablets in stock. How many tablets should be given? Really need help with this! :/ Thanks -MC
Monday, January 27, 2014 at 5:54pm

chemistry
df
Monday, January 27, 2014 at 5:09pm

Chemistry
==> NH4^+(aq) + Cl^-(aq) + H2O(l)
Monday, January 27, 2014 at 4:24pm

Chemistry
Given the reactant side of the total ionic equation for the neutralization reaction of ammonium hydroxide (NH4OH) with hydrochloric acid (HCl), write the total ionic equation (also known as the complete ionic equation) by entering both the reactant and the product species, ...
Monday, January 27, 2014 at 4:09pm

chemistry
-.00574
Monday, January 27, 2014 at 11:51am

Chemistry
g H2O x 0.888 = 50
Monday, January 27, 2014 at 11:33am

Chemistry
You must know how many mols ethanol. Assuming 1 mol ethanol, then 713 kJ/molX x # mols X = 1370 kJ
Monday, January 27, 2014 at 11:29am

chemistry
Those constants usually are quite accessible. If they are not in your text/notes, you can google " table freezing point depression constants"
Monday, January 27, 2014 at 11:25am

chemistry
why is it that protonated pyrone have a higher pKa than protonated acetone?
Monday, January 27, 2014 at 9:52am

Chemistry
The excess is 0.001mol but this answer is in L so if you multiply it by 1000 to make your answer in mol/mL like the original question, you will get the answer 1.1mol/mL and that is the first choice: 1.1mol HCl.
Monday, January 27, 2014 at 8:01am

Chemistry
The excess is 0.001mol but this answer is in L so if you multiply it by 1000 to make your answer in mol/mL like the original question, you will get the answer 1.1mol/mL and that is the first choice: 1.1mol HCl.
Monday, January 27, 2014 at 8:01am

chemistry
what is the freezing point depression of water, benzene, acetic acid, ethanol and clyclohexane?
Monday, January 27, 2014 at 7:19am

organic chemistry
why is it that protonated pyrone have a higher pKa than protonated acetone?
Monday, January 27, 2014 at 12:49am

Chemistry
Assume that the complete combustion of one mole of ethanol to carbon dioxide and water liberates 1370 kJ/mol (?G°\' = –1370 kJ/mol). If the energy generated by the combustion of ethanol is entirely converted to the synthesis of a hypothetical compound X, calculate...
Monday, January 27, 2014 at 12:46am

Chemistry
Water is composed of 11.2% hydrogen and 88.8% oxygen. what mass of water contains 50.0g of 0xygen?
Monday, January 27, 2014 at 12:13am

chemistry
Set up two equation. They are (1) g NaCl + g KCl = 0.8870g (2) g AgCl from NaCl + g AgCl from KCl = 1.913g If you let X = g NaCl and let Y = g KCl, then equation 1 becomes X+Y = 0.8870 and equation 2 becomes X(MMAgCl/MMNaCl) + Y(MMAgCl/MMKCl) = 1.913 where MM stands for molar ...
Sunday, January 26, 2014 at 11:42pm

Chemistry
You work this in stages. Within a phase it is q = mass x specific heat x (Tfinal-Tinitial). For example, for liquid water at zero C to boiling it will be q = mass H2O x specific heat liquid H2O x (100-0). Then at a phase change (from ice to liquid or from liquid to gas it is q...
Sunday, January 26, 2014 at 11:37pm

Chemistry
How much heat energy, in kilojoules, is required to convert 63.0g of ice at −18.0 ∘C to water at 25.0 ∘C ?
Sunday, January 26, 2014 at 11:23pm

chemistry
1. An 887.0 mg sample of a mixture containing only NaCl and KCl is dissolved in water, and excess AgNO3 is added to yield 1.913 g of AgCl. Compute the mass-% of each compound in the mixture.
Sunday, January 26, 2014 at 11:21pm

Chemistry #30
.50
Sunday, January 26, 2014 at 11:02pm

chemistry
mass = volume x density plug in volume and density and calculat3e mass of each.
Sunday, January 26, 2014 at 10:53pm

Chemistry
Use PV = nRT to find mols. Then g = molx x molar mass
Sunday, January 26, 2014 at 10:51pm

chemistry
2.0 what? I suggest you repost at the top of the page.
Sunday, January 26, 2014 at 10:50pm

Chemistry
I would do this. ........HA --> H^+ + A^- I.......x......0.....0 C......-y......y.....y E .....x-y.....y.....y You know y = 6.17E-5 Substitute and solve for x =initial (HA) and let's call that M1. (This will be quadratic you must solve.) Do the same for HA in which y = ...
Sunday, January 26, 2014 at 10:49pm

chemistry
which weighs more a 101cm ^3 of copper or 92.0cm^3 of iron show work
Sunday, January 26, 2014 at 10:47pm

Chemistry
total volume = 100 + 50 + 10 + 75 = 235 mL. In the final solution at mixing and before equilibrium (A) = 0.001M x (50/235) = ?M (B) = 0.002M x (100/235) = ?M (C) = 1M x (10/235) = ?M (D) = 0.0015M x (75/235) = ?M So you know at equilibrium (D) = 0.0006M. Therefore, the ...
Sunday, January 26, 2014 at 10:31pm

chemistry
(V1/T1) = (V2/T2)
Sunday, January 26, 2014 at 10:20pm

chemistry
I don't understand the g g and the mL mL but 2900 mL x 1 g glucose/100 mL = 29 g glucose. I think glucose is about 4 calories/g; therefore, energy = 4 cal/g x 29g = ?
Sunday, January 26, 2014 at 10:20pm

Chemistry
I suppose that you did everything right (and had a little luck).
Sunday, January 26, 2014 at 10:16pm

Chemistry
2C8H18 + 25O2 ==> 16CO2 + 18H2O 17,500 miles/19.2 mpg = ? gallons. ? gallons x 3.785 liters/gallon. ?liters x 1000 = ?mL ?mL x 0.703 g/mL = ? grams grams octane/molar mass octane = mols octane. Using the coefficients in the balanced equation, convert mols Octant to mols CO2...
Sunday, January 26, 2014 at 10:14pm

chemistry
278.25kj
Sunday, January 26, 2014 at 10:08pm

Chemistry - Posted for Rudy
First, I think you left a squared term off the OH^-. Ca10(PO4)6(OH)2(s) --> 10Ca2+(aq) + 6PO43-(aq) + 2OH-(aq) (Ca^2+) = 10x (PO4^3-) = 6x (OH^-) = 2x Ksp = (Ca^2+)^10(PO4^3-)^6(OH^-)^2 Substituting the x values we have Ksp = (10x)^10(6x)^6(4.3e-6 + 2x)^2 I would make the ...
Sunday, January 26, 2014 at 10:07pm

Chemistry - Posted for Rudy
wouldn't the Ca ion cncentration be 5 times the OH conc?
Sunday, January 26, 2014 at 9:38pm

chemistry
q = mass x specific heat x delta T. 176 J = 28.1 x specific heat x 16.3 Solve for specific heat and compare with the table provided.
Sunday, January 26, 2014 at 9:37pm

Chemistry
1.250/250 = ?
Sunday, January 26, 2014 at 9:34pm

Chemistry
A 1.250 g mass of standard aspirin is dissolved in approximately 20 mL of 1 M NaOH. This solution is added to a 250-mL volumetric flask and diluted to the mark with DI water. How many grams per mL of aspirin are in the resulting solution? (Note that a 250-mL volumetric flask ...
Sunday, January 26, 2014 at 8:39pm

chemistry
An unknown substance has a mass of 28.1 g. The temperature of the substance increases by 16.3 degrees Celsius when 176 J of heat is added to the substance. What is the most likely identity of the substance? The table lists the specific heat capacities of select substances.
Sunday, January 26, 2014 at 7:56pm

Chemistry - Posted for Rudy
Posted by Rudy on Sunday, January 26, 2014 at 7:24pm. Hydroxylapatite, Ca10(PO4)6(OH)2, has a solubility constant of Ksp = 2.34 × 10-59, and dissociates according to Ca10(PO4)6(OH)2(s) --> 10Ca2+(aq) + 6PO43-(aq) + 2OH-(aq) Solid hydroxylapatite is dissolved in water ...
Sunday, January 26, 2014 at 7:32pm

Chemistry
Assuming that gasoline is pure octane (d = 0.703 g/mL), how many metric tons of CO2 are released in a year by an SUV that gets 19 mpg and is driven 17500. miles?
Sunday, January 26, 2014 at 5:27pm

Chemistry
what would be a possible reason for the melting point of a purified sample to be the same as the literature value in a synthesis of salicyclic acid lab??
Sunday, January 26, 2014 at 4:44pm

chemistry
A patient receives 2900mL mL of an IV {\rm IV} solution containing 1g g of glucose per 100 mL. How much energy, in kilojoules, does the patient obtain from glucose, a carbohydrate?
Sunday, January 26, 2014 at 4:04pm

chemistry
a gas has a volume of 95 mL at a pressure of 930 torr. What volume will the gas occupy at standard temperature if pressure is held constant?
Sunday, January 26, 2014 at 3:48pm

Chemistry
Consider the reaction A+B->C+3D. A solution was prepared by mixing 50 ml of .001 M of A, 100 ml of .002 M of B, 10 ml of 1 M of C, and 75 ml of .0015 M of D. At equilibrium, the concentration of D was measured and found to be .0006 M. Calculate the equilibrium ...
Sunday, January 26, 2014 at 3:10pm

Chemistry
Consider 51.5 mL of a solution of weak acid HA (Ka = 1.00 10-6), which has a pH of 4.210. What volume of water must be added to make the pH = 5.000 I've tried everything but I am not getting the right answer!
Sunday, January 26, 2014 at 1:36pm

Chemistry
55cm
Sunday, January 26, 2014 at 1:27pm

chemistry
if you dissolve 20mg of alcl3 into 2.0 of a 2.5 molal nacl solution (density 1.08kg/l), what would be the mass concentration (ppm(weight)) of al3+ in the resulting solution?
Sunday, January 26, 2014 at 1:10pm

Chemistry
exactly what is the volume of maximum inflation.
Sunday, January 26, 2014 at 1:03pm

Chemistry
If each balloon is filled with carbon dioxide at 20 deg. C and 1 atmosphere, calculate the mass and the number of moles of carbon dioxide in each balloon at maximum inflation.
Sunday, January 26, 2014 at 1:02pm

analytical chemistry
at elevated temperature, NaHCO3 (83.98g/mol) is converted quantitatively to Na2CO3 (105.98g/mol).Ignition of 0.3592g sample of an antacid tablet containing NaHCO3 and non volatile impurities yielded a residue weighing 0.2362g. Calculate the percent purity of the sample.
Sunday, January 26, 2014 at 7:17am

chemistry
calculate the expansion work done when 50 g of water is electrolyzed under constant pressure at 25 c...why i get 6.8kj
Sunday, January 26, 2014 at 6:25am

Chemistry
q = mass sample x Ccal x delta T. Divide by 3 to obtain q/1 g sample, and multiply by molar mass to find q for 1 mol KCN. That will give you q in kJ/mol.
Sunday, January 26, 2014 at 12:07am

Chemistry
When a 3.00-g sample of KCN is dissolved in water in a calorimeter that has a total heat capacity of 1.123 kJ·K–1, the temperature decreases by 0.480 K. Calculate the molar heat of solution of KCN.
Sunday, January 26, 2014 at 12:02am

chemistry
the latter is true. Look up the word flux.
Saturday, January 25, 2014 at 10:25pm

chemistry
Say you have two substances, A and B. A has a melting point of 300 degrees Celcius, while B has a melting point of 200 degrees Celcius. If you took a mixed melting point where the ratio of A is higher than B, what would the melting range look like? Would the melting point be ...
Saturday, January 25, 2014 at 8:45pm

Chemistry
All these
Saturday, January 25, 2014 at 7:25pm

Chemistry
I am wonder exactly which air pollutant you are thinking on. freon? Nitrous oxide? carbon monoxide? Sulfur dioxide? carbon dioxide?
Saturday, January 25, 2014 at 7:21pm

Chemistry
Air Pollution: How do I use equations to describe the question "How is it formed?' for the air pollution?
Saturday, January 25, 2014 at 7:19pm

Chemistry
This answer is wrong
Saturday, January 25, 2014 at 5:20pm

AP Chemistry
I tried .15 and it said it was incorrect.
Saturday, January 25, 2014 at 5:12pm

organi chemistry
Calicheamicin is an antitumor compound produced by a microorganism isolated in Texas soil. Below is the enediyne core of calicheamicin, which is responsible for its antitumor activity. (a) Mark the hybridization state of each carbon. Ignore the –R groups. (b) What are the...
Saturday, January 25, 2014 at 12:17pm

Chemistry
rate = -delta [N2O5]/delta time rate = (0.218-0.0296)/282 = ? Then rate = k[A]. Calculate k.
Friday, January 24, 2014 at 10:33pm

Chemistry
The gas phase decomposition of dinitrogen pentoxide at 335 K N2O5(g) 2 NO2(g) + ½ O2(g) is first order in N2O5. During one experiment it was found that when the initial concentration of N2O5 was 0.218 M, the concentration of N2O5 dropped to 2.96E-2 M after 282 s had ...
Friday, January 24, 2014 at 9:35pm

AP Chemistry
I have the same answer you obtained BUT my best guess is that you have reported too many significant figures. You are allowed only two; therefore, I would round that off to 0.15%. Let me know if that clears up the problem (or doesn't clear up the problem).
Friday, January 24, 2014 at 8:44pm

AP Chemistry
.........HX | H2O ==> H3O^+ X^- I.......0.001..........0.....0 C........-x...........x......x E......0.001-x........x......x Ka = (H3O^+)(X^-)/(HX) (H3O^+) = 0.001*0.06 (X^-) = 0.001*0.06 (HX) = (0.001-(0.001*0.06)
Friday, January 24, 2014 at 8:21pm

AP Chemistry
A 0.00100 M solution of a weak acid HX is 6% ionized. Calculate Ka for the acid.
Friday, January 24, 2014 at 8:14pm

AP Chemistry
I got the first two parts correct but I can't seem to get the last part. The concentration I got for H3O^+ is 1.151520734e-3. When I plugged that in for the %ion I got 0.1476308633. I typed that into my homework and it said that is incorrect.
Friday, January 24, 2014 at 8:13pm

what??????chemistry
I think you must have meant 2.29 x (100/2.03) = 112.81g KNO3/100 g H2O which I would round to 113 g solute/100 g H2O
Friday, January 24, 2014 at 8:00pm

AP Chemistry
........H2O ==> H^+ + OH^- I......liquid....0.....0 C......liquid....x......x E.....liquid.....x......x So Kw = (H^+)(OH^-) Substitute and solve for H^+ and pH.
Friday, January 24, 2014 at 7:52pm

AP Chemistry
(H^+) for a salt of a weak acid and a weak base = sqrt(KwKa/Kb). Solve for (H^+) and you have your answer.
Friday, January 24, 2014 at 7:48pm

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