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April 20, 2014

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

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Chemistry
1 atm = 10.1 Newtons/cm^2 to find that type 1 atm = Newtons/cm^2 into a Google search box 10.1 Newtons/cm^2 * 17.5*10^3 cm^2 = 177,000 Newtons use the Google search box again: 177000 newtons = pounds and you will get back 39,791 pounds
Friday, February 14, 2014 at 7:37pm

Chemistry
Steve gave you the combined gas law, but it seems that you were confused. The gas law is as followed: P1V1/T1=P2V2/T2 Where P1=75.0 cmHg V1=500.0 mL T1=273K +(-185ºC)=88K P2=55.0 cmHg V2=221.0mL and T2=? Solve for T2: T2=[T1*(P2V2)]/P1V1 T2=[88K*(55.0 cmHg*221.0mL)/(75.0 ...
Friday, February 14, 2014 at 7:14pm

Chemistry
If the surface area of a human body is 17,500 square centimeters, what is the total weight of the atmosphere on a human body expressed in pounds?
Friday, February 14, 2014 at 7:08pm

Chemistry
This answer is not correct
Friday, February 14, 2014 at 6:40pm

chemistry
C
Friday, February 14, 2014 at 6:36pm

Chemistry
PV/T remains constant, so (75.0)(500)/(-185+271) = (55)(221.0)/T T = 28°K Note that we don't really have to convert to L and Pa, because the same conversion factors would be applied to both sides of the equation. The only wrinkle is the °C-°K conversion, ...
Friday, February 14, 2014 at 6:31pm

Chemistry
A sample of oxygen gas occupies 500.0 mL at -185°C and 75.0 cmHg. Calculate the temperature in °C if the gas has a volume of 221.0 mL at a 55.0 cmHg.
Friday, February 14, 2014 at 6:10pm

Chemistry
A sample of gas has a volume of 1.30 L at STP. What is the temperature in °C if the volume is 13.0 L at 2.00 atm?
Friday, February 14, 2014 at 6:09pm

Chemistry
Chester makes 1L of a 0.01M HCl solution and measure the pH. Burt then adds 5.80 g of sodium chloride to Chester’s solution and measures the pH. Calculate the difference between the two pH values obtained.
Friday, February 14, 2014 at 6:05pm

chemistry
544
Friday, February 14, 2014 at 5:00pm

chemistry
Breaking the hydrogen bond between two water molecules is called dissociation
Friday, February 14, 2014 at 4:51pm

Chemistry
After finding the moles of H2, do the mole ratio between H2 and X in the equation. After that you have the grams of X and moles of X divide the grams by the moles and you will find the molar mass.
Friday, February 14, 2014 at 4:08pm

Chemistry
If the equilibrium constant K equals .05, and the reaction C3H8=C3H6 + H2 (all gases), starts with pure C3H8 and is allowed to reach equilibrium at 200 K at a total pressure of 2 bar. Calculate the partial pressure of H2 at equilbirum.
Friday, February 14, 2014 at 3:25pm

chemistry
what the balance equation for solid carbon
Friday, February 14, 2014 at 3:18pm

Chemistry
2Mg + O2 ==> 2MgO 3Mg + N2 ==> Mg3N2 Mg3N2 + 6HOH ==> 3Mg(OH)2 + 2NH3 I would make up some convenient numbers (such as 24.3g Mg) and calculate how much MgO was produced and how much O in the MgO, then calculate the formula from that. Then go through the same ...
Friday, February 14, 2014 at 3:16pm

Chemistry
Assume that some of the magnesium nitride is not completely converted to magnesium hydroxide and subsequently to magnesium oxide. Will your empirical formula be too high in magnesium or too high in oxygen? Please show any calculations you used to determine your answer. Where ...
Friday, February 14, 2014 at 3:08pm

chemistry
wtf
Friday, February 14, 2014 at 2:57pm

Chemistry
There are two open beakers placed in a sealed box at constant temperature. Beaker 1 has 25 ml of .1 M NaCl in water. Beaker 2 has 45 ml of .05 M NaCl in water. What happens as the system goes towards equilibrium and what is the final contents in each beaker?
Friday, February 14, 2014 at 2:04pm

Chemistry
The free energy profile as the reaction goes from reactants to products is a straight diagonal line from 50 kj/mol to 80 kj/mol. Is the reaction exothermic or endothermic? Does the reaction involve only pure solids and liquids? Is the equilibrium constant greater than, equal ...
Friday, February 14, 2014 at 2:02pm

chemistry
This is a limiting reagent (LR) problem. I know that because amounts are given for BOTH reactants. 1. Convert grams Hg to mols. mols = grams/molar mass. 2. Do the same for g oxygen to mols. 3a. Using the coefficients in the balanced equation, convert mols Hg to mols HgO. 3b. ...
Friday, February 14, 2014 at 12:19pm

chemistry
How did you get the answer for letter C
Friday, February 14, 2014 at 11:29am

chemistry
37
Friday, February 14, 2014 at 8:02am

chemistry
2Hg+O2=2HgO if 50.0 grams of mercury reacts with 50.0 grams of oxygen gas, how many grams of mercury(ii)oxide are produced?
Friday, February 14, 2014 at 2:23am

chemistry
How many mols do you have? That's mols = grams/molar mass = approx 0.023 but you need to do it more accurately. Then 1 mol contains 6.02E23 atoms. So 0.023 mols will contain ...... atoms.
Thursday, February 13, 2014 at 11:54pm

chemistry
A sample of barium contains 3.20g of barium. How many atoms of barium are contained in the sample?
Thursday, February 13, 2014 at 11:38pm

Chemistry
The second reaction has no change in the number of moles of gas, so w = 0, and ΔU = ΔH.
Thursday, February 13, 2014 at 11:20pm

chemistry
I got 30 this time! Yay! Thank you so much DrBob222! I really appreciate it!
Thursday, February 13, 2014 at 10:32pm

oops--chemistry
my error. I read that as 200 g SOLUTION but it is 200 g H2O 23% NaCl is 23 g/100 g solution which is 23 g NaCl in 77 g H2O. grams NaCl in 200 g H2O is 23 x 200/77 = ? and ?/2 = ?cc.
Thursday, February 13, 2014 at 10:26pm

chemistry
I got 23...but the answers available are a. 10 mL b. 30 mL c. 50 mL d. 100 mL ... is there something that I am doing incorrectly?
Thursday, February 13, 2014 at 10:13pm

chemistry
23% NaCl is 23 g NaCl/100 g solution. so 200 g soln is 46g NaCl. mass = volume x density so volume = mass/density = 46/2 = ? cc.
Thursday, February 13, 2014 at 9:47pm

chemistry
Convert 16,700 cm^2 to in^2. I would use Google for that. Then in^2 x 14.7 lb/in^2 = ? lbs.
Thursday, February 13, 2014 at 9:38pm

chemistry
An ice-bath made with sodium chloride will be 9 ± 1 oC when the solution is about 23% sodium chloride by mass. The density of solid sodium chloride is about 2 g/cm3. What volume of solid NaCl would you add to 200 g water to make a 23% NaCl solution? ANY HELP WOULD BE ...
Thursday, February 13, 2014 at 9:37pm

chemistry
(P1/T1) = (P2/T2) Remember T is in kelvin.
Thursday, February 13, 2014 at 9:33pm

chemistry
If the surface area of a human body is 16,700 square centimeters, what is the total weight of the atmosphere on a human body expressed in pounds?
Thursday, February 13, 2014 at 9:31pm

chemistry
Calculate the final Celsius temperature of sulfur dioxide if 0.500 L of the gas at 35°C and 650 mmHg is heated until the pressure reaches 742 mmHg. Assume the volume remains 0.500 L.
Thursday, February 13, 2014 at 9:30pm

chemistry 101
That didn't help drbob22
Thursday, February 13, 2014 at 9:18pm

Chemistry
As2S3 is #1 (known as arsenious sulfide in the old days.) SiI4 SbBr3 NH3 Pb^2+
Thursday, February 13, 2014 at 8:43pm

Chemistry
How many mols do yo want? That's M x L = ? Then mols = grams/molar mass
Thursday, February 13, 2014 at 8:41pm

Chemistry
I don't get it. Aren't these the names? Perhaps you want the formula. By the way, the Stock system uses Roman numerals. You have used the number 1; you should use the capital i so it would look like this. arsenic (III) sulfide. etc.
Thursday, February 13, 2014 at 8:39pm

chemistry
NH3 + HCl --> NH4Cl + H2O millimols NH3 = 200 x 1 = 200 mmols HCl added = 200 x 0.5 = 100 So you have 100 mmols NH3 in 400 mL solution. I assume from your post that you worked the remainder of part a. For part b we have the soln from part a and add 15 mmols (15x1) NaOH. So ...
Thursday, February 13, 2014 at 8:34pm

Chemistry
What mass of NaOH is required to create 500 mL of a .4 M solution of Sodium Hydroxide(aq)?
Thursday, February 13, 2014 at 8:30pm

Chemistry
I am supposed to name this using IUPAC method for binary compounds (i think) arsenic(111) sulfide silicon tetraiodide antimony (111)bromide ammonia gas lead(11) and the things in the brackets are supposed to be the roman numerals
Thursday, February 13, 2014 at 7:44pm

chemistry
A 1M solution (200ml) of NH3 (Kb of ammonia=1.8*10-5) is added to 200ml of 0.5M HCl. Calculate: a) the resulting pH? b) The delta ph due to addition of 15ml of 1M HNO3 to solution obtained in part a c) I am stuck on this: The delta ph due to addition of 15ml of 1M NaOH to the ...
Thursday, February 13, 2014 at 7:05pm

chemistry
Ba^2+(aq) + SO4^2-(aq) ==> BaSO4(s)
Thursday, February 13, 2014 at 6:02pm

chemistry
solve net ionic equATION Ba(OH)2 + Na2SO4
Thursday, February 13, 2014 at 4:26pm

chemistry
The pH value would be C.1.3
Thursday, February 13, 2014 at 1:18pm

chemistry
If we have a concentration of H+ at 5 x 10-2 mol/L, what is the pH value? A. -1.30 B. 0 C. 1.3 D. 2.6
Thursday, February 13, 2014 at 1:09pm

chemistry
What is your question? By the way, lower case where upper case should be used isn't anything. And there is no such animal as hci. HCl perhaps. Not hci.
Thursday, February 13, 2014 at 12:50pm

Chemistry: Please check answers
The prefixes cis- and trans- are used to identify _____ isomers.
Thursday, February 13, 2014 at 11:30am

chemistry
2 nacl (aq) + h2so4 ==> na2so4 (aq) + 2 hci (g)
Thursday, February 13, 2014 at 9:48am

12th grade chemistry
jjj
Thursday, February 13, 2014 at 4:44am

Chemistry
For each mL you used it is that, yes. I don't know the details of the experiment but if all of the 1 mL was consumed then the amount consumed is M x L = ?, yes.
Thursday, February 13, 2014 at 12:30am

Chemistry
So it would be (0.20M)(1.0ml/1000L)=0.0002moles of S2O3 consumed ?
Thursday, February 13, 2014 at 12:23am

Chemistry
mols = M x L
Thursday, February 13, 2014 at 12:17am

chemistry
63.38/2 = 31.69g = 1 eq. 1.25 eq would be 1.25*31.69 = about 49.86g. mols = grams/molar mass= about 0.625 mols.
Thursday, February 13, 2014 at 12:14am

Chemistry
For chem we did a kinetics lab based on the rate of reaction of peroxydisulfate ion with iodide ion. I'm supposed to find the amount of S2O3 ^2- consumed for every trial (in moles) If someone could just explain how to do that with the information I currently have, that ...
Thursday, February 13, 2014 at 12:10am

chemistry
I am performing debromination of 1,2-diphenylethane. the reaction is a 1:1 ratio of moles. I have .41g of the dibromide compound and I need 1.25 equivalents of zinc. How many moles of zinc is that?
Thursday, February 13, 2014 at 12:02am

chemistry
Technically, we don't know eqivalents without a reaction but there are three definitions that are usually used. The strict definition for chemistry is that amount of substance that will react with 1 g H2. For your question, the equivalent weight of Zn is the atomic mass of...
Wednesday, February 12, 2014 at 11:53pm

chemistry
What is the definition of an equivalent? a lab procedure requires 1.25 equivalents of zinc powder. How do I determine how much zinc that is?
Wednesday, February 12, 2014 at 11:45pm

chemistry
Strange wording. I assume you want to know % yield when 20g Znb produced 5.4L H2. Zn + H2O ==> ZnO + H2 mols Zn = grams/atomic mass Use the coefficients in the balanced equation to convert mols Zn to mols H2. Note that is a 1:1 conversion. Then convert mols Zn to L. 1 mol ...
Wednesday, February 12, 2014 at 11:38pm

chemistry
very hot sinc will react with steam to form zinc oxide and hydrogen. If 5.4 liters of hydrogen was used to use up 20 g of zinc completely. What is the percent yield of this process
Wednesday, February 12, 2014 at 11:28pm

Chemistry
If the person bails at the same rate as the boat is taking on water, neither side wins and the boat contains the same amount of water as time marches on.
Wednesday, February 12, 2014 at 9:34pm

Chemistry
See your other post.
Wednesday, February 12, 2014 at 9:33pm

Chemistry
It isn't a matter of strong base vs weak acid as much as it is the number of mols of each and how the salt reacts with H2O. HA + NaOH ==> H2O + NaA mols HA = 0.01 mols NaOH = 0.01 So the solution EXACTLY neutralizes and there is no excess NaOH or HA. You might think the...
Wednesday, February 12, 2014 at 9:20pm

Chemistry
I suggest you read in your text/notes or Google "intermolecular forces".
Wednesday, February 12, 2014 at 9:11pm

Chemistry
Explain how a person bailing out a row boat with a leak could represent a state of physical equilibrium.
Wednesday, February 12, 2014 at 9:06pm

Chemistry
Br2(l)+Cl2(g) (double arrow) 2BrCl(g) dH=+29.4 kJ/mol I am having trouble understanding this. Will the system shift left, right, or unchanged and why? a.Increasing Temp. b. Increasing pressure in flask by adding Ar. c. Increasing volume of flask d. Adding Br2(l)...is answer ...
Wednesday, February 12, 2014 at 9:02pm

Chemistry
.01 mols of a weak acid is dissolved in .1 L of water. That solution is then reacted with .01 mols of NaOH. Would the resulting solution be acidic, basic, or neutral? Why? What reaction equations support the explanation? I think the answer is that the resulting solution would ...
Wednesday, February 12, 2014 at 8:52pm

Chemistry
What are four types of interactions between liquid molecules that affect the boiling point.
Wednesday, February 12, 2014 at 8:47pm

Chemistry
2HNO3 + Na2CO3 ==> CO2 + H2O + 2NaNO3 mols HNO3 = grams/molar mass = ? Use the coefficients in the balanced equation to convert mols HNO3 to mols Na2CO3. Then convert mols Na2CO3 to grams. g = mols x molar mass = ?
Wednesday, February 12, 2014 at 8:32pm

AP Chemistry- Acids
pH = -log(HNO3) -1.39 = log(HNO3) I found HNO3 approximately 0.05 but you need to do it more accurately. Then mol HNO3 = M x L = ? mols HCl = M x L total mols H^+ = mols HCl + mols HNO3. volume = 145 mL + 493 mL = ? M new solution = total mols/total liters. Then pH = -log(H^+)
Wednesday, February 12, 2014 at 8:30pm

Chemistry- acids/bases
See your other post.
Wednesday, February 12, 2014 at 8:26pm

Chemistry- acids/bases
M Ba(OH)2 solution = 0.0921 x (45.0/350.0) = ? M Ba(OH)2 is a strong base (ionizes 100%) to concn Ba(OH)2 is ?M from above. Then (OH^-) - twice that of the base since there are two OH ions per molecule of Ba(OH)2.
Wednesday, February 12, 2014 at 8:25pm

Chemistry
2.15
Wednesday, February 12, 2014 at 7:59pm

Chemistry- acids/bases
Find the concentration of OH- of a solution of 45.0mL of 0.0921 M Ba(OH)2 diluted with enough water to make 350.0 mL of solution.
Wednesday, February 12, 2014 at 7:14pm

Chemistry- acids/bases
Find the concentration of OH- of a solution of 45.0mL of 0.0921 M Ba(OH)2 diluted with enough water to make 350.0 mL of solution.
Wednesday, February 12, 2014 at 7:13pm

AP Chemistry- Acids
What is the pH of a solution obtained by adding 145mL of 0.575M HCl to 493mL of a HNO3 solution with a pH of 1.39?
Wednesday, February 12, 2014 at 6:27pm

Chemistry
What mass, in grams, of sodium carbonate is required for complete reaction with 8.35g of nitric acid to produce sodium nitrate, carbon dioxide, and water? [Show work]
Wednesday, February 12, 2014 at 6:18pm

Chemistry
Got it, thanks!
Wednesday, February 12, 2014 at 2:16pm

Chemistry
mol fraction = X XO2 = nO2/total mols XN2 = nN2/total mols Then pO2 = XO2*Ptotal and pN2 = XN2*Ptotal
Wednesday, February 12, 2014 at 1:53pm

Chemistry
2
Wednesday, February 12, 2014 at 1:34pm

Chemistry
Exactly 1.0 mole of oxygen and 7.0 moles of nitrogen gas are in a container. The total gas pressure is 5.7 atm. What is the partial pressure of nitrogen in atm? I'm not sure how to go about setting up the problem. Any help is appreciated!
Wednesday, February 12, 2014 at 11:52am

Chemistry
p1v1 = p2v2
Wednesday, February 12, 2014 at 11:48am

chemistry
PV = nRT
Wednesday, February 12, 2014 at 11:47am

chemistry
you have a metal tank containing 74.0moles of nitrogen gas at a pressure of 15.0atm.If the pressure is measured at a temperature of 20.0c,then the volume of the tank must be how many liters(Round answer to one decimal place.
Wednesday, February 12, 2014 at 11:44am

Chemistry
when the pressure on 2.5liters of oxygen is decreased from 2.0atm to 1.0atm,the volume of the gas becomes how many liters.(round answer to one decimal place.
Wednesday, February 12, 2014 at 11:40am

Chemistry
All the Quetions can be : a-Volume percent ? b-Mass percent ? c-molarity ? d-molality ? e-mole fraction ? answers: assume 10 mL of ethylene glycol and 10 mL of water mass ethylene glycol = 10 mL x 1.114 g/mL = 11.14 g mass water = 10 mL x 1.00 g/mL = 10.0 g mass solution = 11....
Wednesday, February 12, 2014 at 10:22am

Chemistry
Yep, I caught it. Thanks for your help!
Wednesday, February 12, 2014 at 7:21am

Chemistry
That's what I obtained, too. I see you picked up on my typo, I wrote M2/M2 and it should have been sqrt(M2/M1)
Wednesday, February 12, 2014 at 1:08am

Chemistry
It makes senses that the molar mass would be smaller than that of CH4 if it diffuses faster. 1/2 = square root of 22/88 = 22 g/mol ?
Wednesday, February 12, 2014 at 12:02am

Chemistry - DrBob222
It did help. Thank you very much :-)
Tuesday, February 11, 2014 at 11:53pm

Chemistry
I don't think so. If the unknown diffuses twice as fast it MUST be smaller (thqat is must have a molar mass less than that of CF4) If I call CF4 rate = 1L/min = r1 Then rate of unknown is 2L/min = r2 molar mass M1 = CF4 = 88 r1/r2 = (sqrt M2/M2) 1/2 = (sqrt M2/88) Solve ...
Tuesday, February 11, 2014 at 11:51pm

Chemistry
I used the formula given and came up with 352 g/mol, would that be correct?
Tuesday, February 11, 2014 at 11:40pm

Chemistry urgent
I would have to say hex-1-ene.
Tuesday, February 11, 2014 at 11:33pm

Chemistry - DrBob222
I do not know who provided you the names, but 1-chlorohexane is not valid: it should just be Chlorohexane. Chlorohexane and dodecane are the two primary products from the termination step in free radical halogenation, as well as HCl, therefore you can rule those two answers ...
Tuesday, February 11, 2014 at 11:26pm

Chemistry
The easy way to do it is to make up a number (use any convenient number) for CH4, then make the rate twice as fast for the unknown gas.
Tuesday, February 11, 2014 at 10:59pm

Chemistry - DrBob222
Ava. I'm not an organic chemist and I don't know the answer. I googled "free radical halogenation of alkanes" and came up with this. It may or may not help. http://en.wikipedia.org/wiki/Free-radica​l_halogenation
Tuesday, February 11, 2014 at 10:58pm

Chemistry
A gas diffuses twice as fast as CF4 (g). The molecular mass of the gas is: I'm not sure how to figure this out without the rates of diffusion.
Tuesday, February 11, 2014 at 10:56pm

Chemistry
This may help. http://www.wikihow.com/Build-a-Calorimet​er
Tuesday, February 11, 2014 at 10:51pm

Chemistry - DrBob222
C6H14 + Cl2 in UV light Below are 5 products, say which one cannot be a product, prove this by showing how each of the other products were formed from the equation above. 1-chlorohexane 2-chlorohexane 2,2-dichlorohexane dodecane hex-1-ene
Tuesday, February 11, 2014 at 10:41pm

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