Thursday
April 24, 2014

Search: It takes 412 kJ/mol to break a carbon-hydrogen single bond

Number of results: 9,641

Math
a + b represents any real number. ^412 sqrt(a+b)^412
Sunday, May 8, 2011 at 8:07pm by Whosthatgirl

Organic Chemistry
What is the theoretical volume (at STP) of butene product that can be obtained from the dehydration of 0.412 g of 2-butanol? (MW = 74 g/mol; 22.414 L/mol) A. 125 L B. 1.36 L C. 125 mL D. 0.000248 L Can you please show calculations
Friday, March 6, 2009 at 5:11am by nilee

Chemistry
Magnesium metal reacts with hydrochloric acid to produce hydrogen gas H2 Mg + 2HCl ----> MgCl + H2 Calculate the volume (in liters) of hydrogen produced at 33 degrees C and 665 mmHg from 0.0840 mol Mg and excess HCl P= .875 atm V= ? n= .0840 mol R= 0.0821 T= 306 K V= nRT/ P...
Tuesday, October 23, 2007 at 7:57pm by Lauren

Chemistry
Seawater contains 0.412 g Ca per kilogram of water. What is the number of moles of Ca per kilogram of water? What is the concentration of Ca measured in ppm? For the first question, it's changing the grams of Ca to moles of Ca. Is it .412 g / 39 g = .0105 moles. For the second...
Wednesday, February 23, 2011 at 9:24am by Unknown

Chemistry
The titration of a 50.0 mL solution of the monoprotic bromoacetic acid (pKa = 3) takes 10 ml of 0.01 mol L-1 NaOH to reach the stoichiometric point. What was the initial concentration of bromoacetic acid? A) 0.02 mol/L B) 0.01 mol/L C) 0.002 mol/L D) 0.001 mol/L
Friday, March 12, 2010 at 3:22am by Connie

4th grade math
1.) 99,412.55 2.) 44,499.77 How would you round the following to the nearest tenth? Would #1 be 99,412.60? Would #2 be 44,499.80? Please explain if I'm incorrect. Thank you in advance.
Monday, March 1, 2010 at 9:21pm by Yan

chemistry(just need to clarify, no need to solve)
When a sample of NO2(g) (5.641 mol) is placed in 360.0 L reaction vessel at 716.0 K and allowed to come to equilibrium the mixture contains 3.412 mol of NO(g). What is the equilibrium concentration (mol/L) of NO(g)? When a sample of PCl5(g) (1228 grams) is placed in 270.0 L ...
Monday, April 12, 2010 at 1:37am by bme1

Chemistry
How long would it take for 2.2 x 10^-4 mol H2 to effuse through the same orifice as the 2.2x 10^-4 mol N2? (It takes 105s for N2 to effuse) I was thinking of setting up the equation like: sqroot(28.014gN2/mol / 2.016g H2/mol) = 3.728 What should I do next? Also, when setting ...
Sunday, September 29, 2013 at 10:27am by Nikki

AP Chem
The energy change H associated with the reaction NBr3(g) + 3H2O(g) -> 3HOBr(g) + NH3(g) is +81 kJ/mol rxn. These bond energy values might be useful: O-H 459 kJ/mol; N-H 386 kJ/mol; O-Br 201 kJ/mol. The strength of the N Br bond is 1. 4 kJ/mol 2. 465 kJ/mol 3. 66 kJ/mol 4. ...
Sunday, November 7, 2010 at 4:31pm by Beth

Chemistry
Please explain. The average bond enthalpy for the C-H bond is 412 kJ mol^-1. Which process has an enthalpy change closest to this value ? A. CH 4 (g)---> C(s)+2H2(g) B. CH 4(g)--> C(g)+2H2(g) C. CH 4(g)---> C(s)+ 4H(g) D. CH 4 (g)---> CH3(g)+ H(g)
Monday, November 11, 2013 at 5:36pm by Anonymous

CHEMISTRY
Please explain. The average bond enthalpy for the C-H bond is 412 kJ mol^-1. Which process has an enthalpy change closest to this value ? A. CH 4 (g)---> C(s)+2H2(g) B. CH 4(g)--> C(g)+2H2(g) C. CH 4(g)---> C(s)+ 4H(g) D. CH 4 (g)---> CH3(g)+ H(g)
Monday, November 11, 2013 at 6:34pm by Anonymous

chemistry
Which of the following mixtures will be a buffer when dissolved in a liter of water? a. 0.1 mol Ca(OH)2 and 0.3 mol HI b. 0.3 mol NaCl and 0.3 mol HCl c. 0.4 mol NH3 and 0.4 mol HCl d. 0.2 mol HBr and 0.1 mol NaOH e. 0.2 mol H3PO4 and 0.1 mol NaOH i think e is answer but not ...
Friday, May 21, 2010 at 6:18am by George2

AP Chemistry
The equilibrium constant for thermal dissociation of F2 F2(g)<->2F(g) is 0.300. If initially 1.00 mol F2 is placed in a 1.00 L container, which of the following is the correct number of moles of F2 that have dissociated at equilibrium? 1. 0.130 mol 2. 0.418 mol 3. 0.548 ...
Tuesday, November 26, 2013 at 8:16pm by Gabriella

CHEM
Which of the following mixtures will result in the formation of a buffer solution when dissolved in 1.00 L of water? i) 0.50 mol NaOH and 0.50 mol HCl. ii) 0.50 mol NaCl and 0.25 mol HCl. iii) 0.50 mol NaF and 0.25 mol HF. iv) 0.50 mol NaOH and 0.25 mol HF. v) 0.25 mol NaOH ...
Friday, July 23, 2010 at 1:18pm by B

Chemistry
Consider the reaction: CO(g) + H2O (g) <---> CO2(g)+H2(g) which of the following initial composition will NOT achieve equlibrium? a) 0.25 mol H2, 0.35 mol CO2, and 0.25 mol CO b) 0.25 mol CO, 0.75 mol H2O c) 1.0 mol of CO2 and 0.50 mol H2 d) 0.85 mol CO and 0.25 mol H2 ...
Friday, November 9, 2012 at 12:32am by Ania

CHEM
How do I work the following question? I found the amu of CaCO3=101.0872g/mol; 2HCL=72.92128g/mol; H2O=18.1582g/mol;CO2=44.0098g/mol; and, CaCl2=110.9834g/mol. You carefully weigh out 10.00g of powder and add it to 40.50g of solution. You notice bubbles as a reaction takes ...
Monday, October 1, 2007 at 1:50am by d

CHEMISTRY> HELP QUICK! pls
Calculate the reaction free energy of: H2(g) + I2(g) 2HI(g) when the concentrations are 0.026 mol L-1 (H2), 0.33 mol L-1 (I2), and 1.84 mol L-1 (HI), and the temperature is 700K. For this reaction Kc= 54 at 700 K. +11.6 kJ mol-1 0 kJ mol-1 -11.6 kJ mol-1 +2273 kJ mol-
Sunday, September 5, 2010 at 7:45am by Lucinda

Chemistry
Initially, 1.68 mol of PCl5(g) and 0.36 mol of PCl3(g) are in mixed in a 2.00 l container. It is later found that 1.44 mol of PCl5 are present when the system has reached equillibrium. Calculate the value of the equllibrium. This is what I did: Equation: PCl5(g) <--> ...
Sunday, July 19, 2009 at 6:18pm by Lena

Chemistry(Please check)
Which of the following mixtures will be a buffer when dissolved in 1 liter of water? 0.10 mol Ba(OH)2 and 0.20 mol HCl 0.30 mol KCl and 0.30 mol HCl 0.40 mol NH3 and 0.40 mol HCl 0.20 mol HNO2 and 0.10 mol NaOH 0.20 mol HBr and 0.10 mol KOH My answer is that HNO2 and NaOH will...
Sunday, April 8, 2012 at 3:10pm by Hannah

Chemistry
Predict whether the following reactions will be exothermic or endothermic A) N2(g)+ 3H2(g) --> 2NH3(g) B) S(g) +O2(g) ---> SO2(g) C) 2H2O(g) ---->2H2(g) + O2(g) D) 2F(g) +F2(g) Bond H-H 432 kj/mol N-N(triple bond) 942 kj/mol O=O 494 KJ/Mol F-F 155 KJ/mol H-N 386 KJ/...
Sunday, January 22, 2012 at 10:53pm by Kristen

chemistry 101
How many moles of oxygen are in 3.45 mol of diphosphorus pentoxide? options: 5.75 mol O 13.5 mol O 6.90 mol O 3.45 mol O 17.3 mol O
Friday, July 8, 2011 at 9:10pm by ABCD

College Chemistry
In a reaction vessel, the following reaction was carried out using 0.250 mol of NH3(l) and 0.100 mol of N2(g). 4NH3(l) + N2(g) 3N2H4(l) Which of the following represents the composition in moles in the vessel when the reaction reaches completion? 0 mol NH3, 0.038 mol N2, ...
Monday, March 26, 2012 at 9:23pm by Lisa

Chemistry
In 1901, Thomas Edison invented the nickel-iron battery. The follwing reaction takes place in the battery. Fe(s) + 2 NiO(OH)(s) + 2 H2O(l) Fe(OH)2(s) + 2 Ni(OH)2(aq) How many mole of Fe(OH)2, is produced when 3.70 mol Fe and 6.95 mol NiO(OH) react?
Monday, February 24, 2014 at 3:26pm by Grace

Chemistry
Identify each enthalpy change by name and classify each change as exothermic or endothermic. a)1 mol C3H8 (l) ==> 1 mol C3H8 (g) b)1 mol Hg (l) ==> 1 mol Hg (s) c)1 mol NH3 (g) ==> 1 mol NH3 (l) d)1 mol NaCl(s) + 3.88kJ/mol ==> 1 mol NaCl (aq) e)1 mol NaCL (s) ==&...
Sunday, May 23, 2010 at 4:43pm by Sal

Chemistry
Identify each enthalpy change by name and classify each change as exothermic or endothermic. a)1 mol C3H8 (l) ==> 1 mol C3H8 (g) b)1 mol Hg (l) ==> 1 mol Hg (s) c)1 mol NH3 (g) ==> 1 mol NH3 (l) d)1 mol NaCl(s) + 3.88kJ/mol ==> 1 mol NaCl (aq) e)1 mol NaCL (s) ==&...
Sunday, May 23, 2010 at 9:53pm by Sal

Chemistry
2KClO3 --> 2KCl + 3O2 What mass of O2 can be made from heating 125 g of KClO3? I know that the answer is 49 g O2 but I keep getting a completely different answer, can anyone show me what I'm doing wrong? 125g KClO3 x (2 mol KClO3/ 122.49g KClO3) = 2.04 mol KClO3 2.04 mol ...
Tuesday, March 2, 2010 at 10:23pm by Ana

ap chemistry
Carbon monoxide reacts with oxygen to form carbon dioxide by the following reaction: 2CO2 + O2 yields 2CO2 Delta H for this reaction is -566 kJ/mol run. What is the delta H for CO? 1). +270 kJ/mol 2). -110 kJ/mol 3). +65 kJ/mol 4). -405 kJ/mol 5). -65 kJ/mol 6). -182 kJ/mol 7...
Thursday, October 18, 2012 at 11:43pm by bridget

Chemistry
Distillation Scale up: In an experiment 100 lb-mol of 47 lb-mol % ethanol, 53 lb mol % water sol'n is fed into distillation column and separated into two streams: 100lb-mol 0.470 lb-mol ethanol 0.530 lb-mol water goes to: steam 1: 17 lb-mol 0.890 lb-mol Ethanol 0.110 lb-mol ...
Saturday, July 7, 2012 at 11:24pm by Simon

chemistry
Which of the following mixtures will result in the formation of a buffer solution when dissolved in 1.00 L of water? i) 0.50 mol HClO2 and 0.25 mol HCl. ii) 0.50 mol HClO2 and 0.25 mol NaOH. iii) 0.50 mol NaClO2 and 0.50 mol HClO2. iv) 0.50 mol NaClO2 and 0.50 mol HCl.
Sunday, March 7, 2010 at 1:10am by Daniel

chem
How many moles of potassium iodide, KI, are required to precipitate all of the lead(II) ion from 25.0 mL of a 1.6 M Pb(NO3)2 solution? A. 0.020 mol B. 0.040 mol C. 0.080 mol D. 0.64 mol E. 64 mol
Sunday, April 28, 2013 at 3:48pm by victoria

Chemistry e
The rusting of iron is represented by the equation 4Fe +3O2 --> 2Fe2O3. If you have a 1.50-mol sample of iron, how many moles of Fe2O3 will there be after the iron has rusted completely? a. 0.50 mol b. 0.75 mol c. 1.0 mol d. 1.50 mol e. 2.0 mol --> I got "b" using ratios...
Tuesday, January 18, 2011 at 6:05pm by Kaye

ap chemistry
Carbon monoxide reacts with oxygen to form carbon dioxide by the following reaction: 2CO + O2 yields 2CO2 Delta H for this reaction is -135.28 kcal. If 811.7 kcal is released, how many moles of CO must have reacted? 1). 270.5 mol 2). 40.5 mol 3). 12.0 mol 4). 5.41 mol 5). 16.3...
Thursday, October 18, 2012 at 11:48pm by bob

AP Chemistry
Carbon monoxide reacts with oxygen to form carbon dioxide by the following reaction: 2CO(g) + O2(g) --> 2CO2(g) change in H for this reaction is −135.28 kcal. If 811.7 kcal is released, how many moles of CO must have reacted? 1. 16.3 mol 2. 40.5 mol 3. 12.0 mol 4. 5....
Sunday, September 29, 2013 at 5:48pm by Anonymous

chemistry:)
The bond enthalpy of the BrCl bond is equal to DH for the reaction BrCl(g)-> Br(g) + Cl(g). Use the following data to find the bond enthalpy of the BrCl bond. Br2(l)--->Br2(g) H=30.91 KJ/mol Br2(g)--->2Br2(g) H=192.9 KJ/mol Cl2(g)---->2Cl(g) H=243.4 KJ/mol ...
Wednesday, June 6, 2012 at 3:22pm by April

chemistry:)
The bond enthalpy of the BrCl bond is equal to DH for the reaction BrCl(g)-> Br(g) + Cl(g). Use the following data to find the bond enthalpy of the BrCl bond. Br2(l)--->Br2(g) H=30.91 KJ/mol Br2(g)--->2Br2(g) H=192.9 KJ/mol Cl2(g)---->2Cl(g) H=243.4 KJ/mol ...
Saturday, June 9, 2012 at 8:28am by April

chemistry
Three solutions are mixed together to form a single solution. One contains 0.2 mol \rm mol Pb(CH 3 COO) 2 \rm Pb(CH_3COO)_2, the second contains 0.1 mol \rm mol Na 2 S \rm Na_2S, and the third contains 0.1 mol \rm mol CaCl 2 \rm CaCl_2. Write the precipitation reaction.
Saturday, October 19, 2013 at 11:55am by cc

Chemistry
Dr. Bob ok well here is what i have gotten so far: on the problem H2O: 1.118 mol C2O4: .58681 mol Fe 3+: .2025 mol K^+: .3862 mol That is what ive gotten doing 20.14 g(1 mol / 18 g) = 1.118 mol and so on with the rest of them Did i do that wrong
Sunday, May 4, 2008 at 7:04pm by LT

Chemistry
C6H14 + 19/2 O2 -> 6 CO2 + 7H2O delta H = -4163 kJ What mass of hexane is required to produce 1.0E5 kJ of heat by complete combustion? -4163 kJ/mol x mol C6H14 = 1E5/-4163 kJ/mol Mol = 1E5/-4163 kJ/mol Mol = -24 mol I know I can do m=n x MM now, but shouldn't the value of ...
Monday, February 11, 2013 at 6:51pm by A Canadian

Chemistry
srry I placed the question in the wrong spot. The equation is 2NH3 <=> N2 + 3H2 1 mole of NH3 injected intoa 1L flask 0.3 moles of H2 was found the concentration of N2 at equlibrium is 0.1M how do I find the concentration of NH3 at equlibrium? (N2) = 0.1 (H2) = 0.3 ...
Tuesday, May 8, 2007 at 6:14pm by Bethany

ap chem
calculate the lattice enthalpy of potassium fluoride from the following data: enthalpy of formation of K(g): +89 kJ mol−1 first ionization energy of K(g): +418 kJ mol−1 enthalpy of formation of F(g): +79 kJ mol−1 electron affinity of F(g): +328 (H = &#...
Tuesday, July 13, 2010 at 1:57am by alexandra

CHEM:
The bond enthalpy of the Br−Cl bond is equal to H for the reaction BrCl(g) Br(g) + Cl(g). Use the following data to find the bond enthalpy of the Br−Cl bond. Br2(l)--->Br2(g) H=30.91 KJ/mol Br2(g)--->2Br2(g) H=192.9 KJ/mol Cl2(g)---->2Cl(g) H=...
Wednesday, June 6, 2012 at 3:13pm by April

chemistry-please check my work
Determine the mass of carbon monoxide that is produced when 45.6 g of methane CH4 react with 73.2 g of oxygen gas, O2. The products are CO and H2O. Please check my work: CH4 + 3O2 ---> 2CO + 2H20 nCH4=2.84 mol nO2=4.58 mol Limiting Reactant: 1 mol CH4/2.84 mol CH4 = 3 mol ...
Friday, May 23, 2008 at 7:34pm by Sarah H

chemistry
What is the formula weight of ammonium oxide? 44.0 g/mol 52.1 g/mol 34.0 g/mol 30.0 g/mol Is it 34.0 g/mol
Wednesday, February 8, 2012 at 6:42pm by krystal

Chem for final, please help!
How many moles of H+(aq) ions are present in 1.25 L of 0.75M Nitric Acid? A. 0.60 mol B. 0.75 mol C. 0.94 mol D. 1.7 mol E. 1.9 mol Please show me how to work this!
Tuesday, December 7, 2010 at 1:27pm by lavonne

chemistry
7. (a) Determine the crystal lattice energy for LiF(s) given that the ∆Hsubl for Li = 155kJ/mol, ∆H0f for F(g) = 78.99kJ/mol, IE1 of Li = 520kJ/mol, EA for Fluorine = -322kJ/mol and the ∆H0f LiF(s) = -589.5kJ/mol (b) For the following reactions: NH4NO3(s) + ...
Friday, August 5, 2011 at 8:07am by ceasar4

chemistry
Nitric oxide reacts with bromine gas at elevated temperatures according to the equation, 2 NO(g) + Br2(g) = 2 NOBr(g) The experimental rate law is rate = k[NO][Br2]. In a certain reaction mixture the rate of formation of NOBr(g) was found to be 4.50 x 10-4 mol L-l s-l. What is...
Friday, February 17, 2012 at 9:09pm by Emile

chemistry
A 79.9-L sample of a gaseous hydrocarbon, measured at 1.00 atm pressure and 25.0C, is burned in excess oxygen, liberating 4.24 10^3 kJ of heat at constant pressure. What is the identity of the hydrocarbon? (R = 0.0821 L atm/(K mol)) Substance Hf (kJ/mol) CO2(g) 393.5 ...
Wednesday, March 30, 2011 at 12:09am by chemistry

Chemistry
How many moles of P4O10 are produced when we react 8 moles of phosphorous with oxygen? I know the answer is: 4 mol P produces 1 mol P4O10 8 mol P produces 2 mol P4O10. Or, 1 mol P4O10 x (8 mol P / 4 mol P) = 2 mol P4O10. but, what is the balanced equation?
Friday, May 3, 2013 at 2:36pm by Timofey

AP Chemistry Help!!
How many moles of P4O10 are produced when we react 8 moles of phosphorous with oxygen? I know the answer is: 4 mol P produces 1 mol P4O10 8 mol P produces 2 mol P4O10. Or, 1 mol P4O10 x (8 mol P / 4 mol P) = 2 mol P4O10. but, what is the balanced equation?
Friday, May 3, 2013 at 5:06pm by Timofey

Chemistry
I did a lab where I put Copper (II) Chloride in water with Alumnim. 2Al + 3CuCl2 -> 3Cu + 2AlCl3 The aluminum on the reactant side weighs 0.5 g and the CuClw weighs 1.69 grams. It said to find the theoricital yield. Did I do this right? 2Al + 3CuCl2 -> 3Cu + 2AlCl3 # of ...
Wednesday, November 5, 2008 at 9:33pm by Lena

Chemistry
"An aqueous sodium borate solution is titrated to the second endpoint with 0.225 mol/l nitric acid in the presence of a suitable indicator. If an average of 12.6mL of titrant are required to reach the second endpoint for a 25.0 mL sample, what is the base concentration?" My ...
Saturday, May 15, 2010 at 12:16am by Stuck

Chemistry
The question representing the production of tetraphosphorus trisulfide (P4S3), a substance used in some match hears, is 8P4 + 3S8 ---> 8P4S3. Determine if each of the following statements is correct. If the statement is incorrect, rewrite it to make it correct. a. To ...
Wednesday, November 14, 2012 at 11:05pm by Montanna

chemistry
Consider the balanced equation 2A(g) + 3G(g) \ 2X(g) + Z(g). To a 20.0 L container maintained at a temperature of 127 C were added 0.200 mol of A, 0.500 mol of G, 0.400 mol of X, and 0.600 mol of Z. After equilibrium was established, it was found that 0.340 mol of X was ...
Sunday, July 27, 2008 at 4:22pm by alexis

CHemistry Dr. Bob please?
for bond energies if tehy give u a diagram of the structure for whatever like c--h--o==h or soemthing amd a chart with c--h=-670 Kj /mol or whatever do u just add all of the KJ/mol together? but what if they only want kJ? would you just multply whatever kJ/mol *1 mol?? how do ...
Tuesday, November 11, 2008 at 5:16pm by Robin

chemistry
If 3 moles of a compound use 12 J of energy in a reaction, what is the Hreaction in kJ/mol? A. -4 kJ/mol B. -0.004 kJ/mol C. 0.004 kJ/mol D. 4 kJ/mol
Wednesday, March 14, 2012 at 2:56pm by princess

Chemistry ?
How many moles are contained in a 4.67-L sample of gas at 30C and 199 kPa? A. 1.7 mol B. 11.8 mol C. 0.37 mol D. 3.7 mol I guessed D, but I'm not sure.
Thursday, August 15, 2013 at 12:57pm by Kaylee

chemistry
Calculate the number of moles in 75.0 g of oxygen gas. A. 2.34 mol O2 B. 4.69 mol O2 C. 750 mol O2 D. 12.5 1023 mol O2 B
Sunday, November 11, 2012 at 6:28pm by Cathy

Chemistry
If at a certain instant during the course of the reaction 2 NO2(g) + F2(g) 2 NO2F(g), the rate of formation of the product were 0.16 mol/L∙s, how fast would the F2 be disappearing (also in mol/L∙s) at that same instant in time? A) 0.16 mol/L∙s B) 0.080 mol...
Monday, July 30, 2012 at 1:58pm by Taylor

Chemistry
How many moles of sodium chloride must be added to an aqueous solution that contains 2.0 moles of silver nitrate in order to precipitate 0.50 moles of silver chloride? A) 0.25 mol B) 0.50 mol C) 1.0 mol D) 2.0 mol E) 1.5 mol The answer is B. I have no idea what to do. I was ...
Sunday, March 22, 2009 at 4:59pm by Jill

chem
18. What is the molecular mass of potassium hydrogen carbonate (KHCO3)? A. 116 g/mol B. 68 g/mol C. 100 g/mol D. 84 g/mol My guess would be A? I got 110.1, but that's not an option.
Thursday, August 15, 2013 at 12:59pm by Jenny

chemistry
Calculate the theoretical percentage of water in gypsum, rounded to the nearest whole number %. (calcium sulfate dihydrate; CaSO4 2H2O; Ca = 40 g/mol, S= 32 g/mol; O= 16 g/mol; H= 1 g/mol).
Wednesday, February 6, 2013 at 9:44pm by tina

Honors Chemistry
"How many grams of NH3 can be produced from the reaction of 28 g of N2 and 25 g of H2? N2 + 3H2 ---> 2NH3 ==> 28 g N2 x (1 mol N2/14.0 g N2) x (2 mol NH3/1 mol N2) x ( 17.0 g NH3/ 1 mol NH3) = 68 g NH3 25 g H2 x ( 1mol H2/2.0 g H2) x (2 mol NH3/3 mol H2) x (17 g NH3/2 ...
Sunday, November 8, 2009 at 8:39pm by Emily

Chemistry
A 2.612 g sample of a copper oxide, when heated in a stream of H2 gas, yields .592 g H20. What is the formula of the copper oxide? Again, I need help with this problem. Answer = CuO Ok nvm.. i got it. Set up the reaction as best we can surmise at the moment. CxOy + H2 ---> ...
Thursday, August 25, 2005 at 10:59am by Laura

Chemistry
"Given that the bond enthalpy of the carbon-oxygen bonds in carbon monoxide and carbon dioxide are 1073 kJ/mol and 743 kJ/mol respectively, and that of the bond in the oxygen molecule is 496 kJ/mol, calculate the enthalpy change for the combustion of 1 mole of carbon monoxide...
Thursday, April 8, 2010 at 10:54pm by Stuck

chemistry
How many moles are in 4.81 x 1024 atoms Na? A. 0.799 mol Na B. 7.99 mol Na C. 481 mol Na D. 7.99 x 10-1 mol Na B
Saturday, November 10, 2012 at 9:50pm by Drew

chemistry
What is the molar mass of hydrogen? A. 1.01 g/mol B. 11.01 g/mol C. 101.1 g/mol D. .0111 g/mol D
Saturday, November 10, 2012 at 10:37pm by Drew

Chemistry
What is the molarity of a solution prepared by diluting 25.0 mL of 0.412 M magnesium nitrate to a volume of 1.50 L please help!
Friday, November 30, 2012 at 10:50pm by Ashley

Math
Rewrite the number sentence with parentheses to make it correct.412=70x5+1-8. And 6x10-5=55
Tuesday, January 8, 2013 at 7:57pm by Zacko

Chemistry
What ratio is used to carry out each conversion? a.mol CH4 to grams CH4 b.L CH4(g) to mol CH4(g)(at STP) c.molecules CH4 to mol CH4 I honestly don't kno what it's asking me I got 1 mol CH4/ 16(g) CH4 for a. 1 mol/22.4 L for b. and 6.02 x 10^23 molecules/1 mol but I don't think...
Friday, July 16, 2010 at 11:48pm by Anonymous

Chemistry
Using the compound for Ibuprofen C13H18O2 find molecules of Ibuprofen that contain 2.84 x10 23 atoms of Hydrogen So for every 1 mol of H= 6.022 x 10 23 molecules of H? (Not sure if Im going in the right direction?) Having trouble setting this up or 1 mol of C13H18O0= 13 mol C...
Monday, November 29, 2010 at 8:34pm by TMV

CHEMISTRY!! NEED IMMEDIATE HELP PLEASE!!!
a. Calculate the delta H, delta G, and equilibrium constant for the reaction of methane with Cl2 to give CH3Cl and HCl. Use the following information for your calculations: Bond Dissociation Energies: CH3-H (104.8kcal/mol), Cl-Cl(59.0 kcal/mol), CH3-Cl(85.0 kcal/mol), and H-Cl...
Sunday, October 30, 2011 at 8:10pm by Natasha

Chemistry Need Help!
Okay, the reaction is this: Naphthalene + HNO3 ---> NitroNapthalene The limiting reagent is Naphthalene The excess is the nitric acid The equation is 1:1 balanced as far as I know 3 g of Nap used in the experiment x 1mol/128.17 g/mol = .023 mol Nap 12.69 g used in the ...
Tuesday, March 4, 2014 at 12:10am by ChrisZZ

science(chem)
I was told before that it takes 2 mol of fluorene to be reduced by 1mol of sodium borohydride.... How many mg of fluorenone can 0.53 mol of sodium borohydride(NaBH4) reduce? what I got... 0.53mol NaBH4 ( 2mol fluorenone/ 1mol NaBH4)(180.192g/1mol fluorenone)(1000mg/1g)= 19,...
Monday, October 8, 2007 at 10:54pm by ~christina~

chemistry
2Na3PO4 + 3CaCl2 ----> Ca3 (PO4)2 + 6NaCl how many moles of CaCl2 remain if .10 mol Na3PO4 and .40 mol CaCl2 are used? When amounts of both materials are listed one must worry about which is the limiting reagentalthough the problem seems to suggest that Na3PO4 is the ...
Wednesday, June 21, 2006 at 6:14pm by Hawk

chemistry
Consider the following reaction at 298 K: C(graphite) +2Cl2 (g) -----> CCl4(l) Calculate the following quantities. Delta H: -139 kJ/mol deltaS(sys)=? J/mol*K deltaS(surr)=? J/mol*K deltaS(univ)=? J/mol*K My answer is: deltaS(sys)=654.9J/mol*K deltaS(surr)=0.4664 J/mol*K ...
Wednesday, March 14, 2012 at 6:47pm by Kelsey

Check a chemistry answer
So I think I have done this problem right, I was just wondering if anyone would check over it for me. What mass (in grams) of P2O5 contains 1.20 x 1023 atoms of phosphorus? 1.20E23 atoms of P x (1 mol/ 6.022E23 atoms) x (5 mol O/ 2 mol P) x (1 mol P2O5/ 5 mol O) x (79.995g/ 1 ...
Thursday, October 14, 2010 at 10:00pm by Tim

Chemistry Check Please! ?Fixed
A solution is prepared by dissolving 3.44 g of sucrose, C12H22O11, in 118 g of water. a) What is the molality of the resulting solution? b) What is the mole fraction of water in this solution? B) moles of h2o=118g/18(g/mol)=6.548 mol moles of c12h22O11= 3.44g/342.3(g/mol)=0....
Friday, January 17, 2014 at 2:52am by Kate

chemistry
The equilibrium constant (Kc) for the gas phase reaction 2 NH3 N2 + 3 H2 is 3.0 x 10-3 at some temperature. The reaction is started by placing a 0.040-mol sample of ammonia in an empty one-liter flask. When equilibrium is established how much N2 is present? 1. ) 0.019 mol 2...
Sunday, October 25, 2009 at 5:28pm by James

Chemistry
In the theoretical reaction 2 B(aq) + 3 D(aq) ---> E(aq) + 4 F(aq) the concentration of D(aq) is 0.40 mol/L. If 25.0 mL of aqueous B is needed to react completely with 30.0 mL of aqueous D, the concentration of B(aq) is A-0.48 mol/L B) B-0.32 mol/L C) C-0.40 mol/L D) D-0.72...
Monday, October 22, 2012 at 3:43pm by mem

CHEM- need help ASAP
An equilibrium mixture in a 10.0 L flask contains 7.0 mol HI(g) and 1.0 mol each of I2(g) and H2(g). If 2.5 mol H2, 5.0 mol I2 and 2.0 mol HI are added to that equilibrium mixture how many moles of each gas will be present when equilibrium is reestablished?
Wednesday, April 16, 2014 at 10:28pm by Meg

chemistry
Nitroglycerin is a powerful explosive, giving four different gases when detonated.2 C3H5(NO3)3 (l) → 3 N2 (g) + 1/2 O2 (g) + 6 CO2 (g) + 5 H2O (g)Given that the enthalpy of formation of nitroglycerin, ΔHf, is −364 kJ/mol, calculate the energy (heat at ...
Saturday, March 3, 2012 at 6:25am by ogi

Science
8. The balanced equation P4 (s) + 6H2 (g) --> 4PH3 tells us that 2 mol H2 a. reacts with 1 mol 4 b. produces 4 mol PH3 c. cannot react with phosphorus d. produces 2 mol PH3 e. reacts with 2 mol P4 idk y i cant seem to get the answer from the choices above?
Tuesday, January 18, 2011 at 6:13pm by Dylan

Chemistry
K=1.6x10^-5 mol/L for the following reaction 2NOCl(g).... 2 NO(g) + Cl2(g) Calculate the concentrations of all species at equilibrium for each of the following original mixtures E) 2.4 mol of NOCl, 2.4 mol of NO, and 1.2 mol Cl2 in a 1.0 L flask F)1.9 mol/L concentration of ...
Tuesday, November 20, 2007 at 8:55pm by AMANDA

chemistry
Calculate how many moles of productwould be produced if .310 mol of the first reactant were to react completely. (a) CO2 + 4 H2 CH4 + 2 H2O CH4 _____ mol H2O _____ mol (b) C3H8 + 5 O2 4 H2O + 3 CO2 H2O _____ mol CO2 _____ mol (c) 3 H2SO4 + 2 Fe Fe2(SO4)3 + 3 H2Fe2(SO4...
Thursday, January 6, 2011 at 6:43pm by Anonymous

ap chemistry
A 0.456 gram sample of an unknown mono- protic acid (lets call it HZ) was dissolved in some water (you pick the amount). Then the acidic solution was titrated to the equivalence point with 32.5 mL of 0.174 M KOH. What is the molecular weight of the unknown acid HZ? 1. 103.2 g...
Tuesday, March 5, 2013 at 8:13pm by cheri

Chem Question (thermo)
Calculate ΔG at 25 C for a reaction in which Ca2+(aq) combines with CO32(aq) to form a precipitate of CaCO3(s) if the concentrations of Ca2+(aq) and CO32(aq) are 0.023 M and 0.13 M, respectively. (ΔG = 47.94 kJ) A. 62.3 kJ/mol B. 33.5 kJ/mol C. 17.8 kJ/mol D...
Thursday, March 1, 2012 at 6:21pm by M

Chemistry
What is the lattice energy of NaI? Use the given information below. Heat of formation for NaI = -288.0 kJ/mol Heat of sublimation for Na = 107.3 kJ/mol Ionization energy for Na = 496.0 kJ/mol Bond dissociation energy for I2 = 149 kJ/mol Electron affinity of I = -295.0 kJ/mol ...
Friday, November 22, 2013 at 1:05pm by Andy

chemistry
What is the lattice energy of NaBr? heat of formation of NaBr = -362 kJ/mol heat of sublimation for Na = 107.30 kJ/mol ionization energy for Na = 496 kJ/mol bond dissociation energy for Br2 = 190 kJ/mol electron affinity of Br = -325 kJ/mol heat of vaporization for Br2 = 30.90...
Saturday, December 4, 2010 at 8:57pm by chemistry

Algebra 1
If Sandra takes 3/14 of the candy, and Elise takes 0.3, whos takes more? Show you're work and conversions.
Wednesday, August 29, 2012 at 7:09pm by Dani.

chemistry
(You may have seen this before) A crude oil burned in electrical generating plants contains about 1.2% sulfur by mass. When the oil burns, the sulfur forms sulfur dioxide gas: S(s) + O2(g) -------> SO2(g) How many liters of SO2 (d = 2.60 g/L) are produced when 1.00 x 104 kg...
Saturday, October 11, 2008 at 2:07pm by starlight

Chemistry
Suppose 1.0 mol of substance A reacts with 1.0 mol of substance B. to produce 2.0 mol of substance C. In a reaction, 2.4 mol of substance A is allowed to react with 2.1 mol of substance B. What amount in moles of substance c is produced?
Wednesday, April 1, 2009 at 10:22pm by Andrew

Chemistry
a. Calculate the delta H, delta G, and equilibrium constant for the reaction of methane with Cl2 to give CH3Cl and HCl. Use the following information for your calculations: Bond Dissociation Energies: CH3-H (104.8kcal/mol), Cl-Cl(59.0 kcal/mol), CH3-Cl(85.0 kcal/mol), and H-Cl...
Sunday, October 30, 2011 at 6:19pm by Jennifer

chemistry
A solution was made by dissolving 62.07 grams of a compound in 500.0 g of water. The compound was not ionic. The freezing point of the solution was measured and found to be 1.86oC. Using the Kf value in your textbook , the molar mass of this compound can be calculated to be ...
Friday, February 3, 2012 at 4:35pm by Anna King

chem
Use bond energies to estimate the enthalpy change for the following reaction C2H2 + H2-> C2H4 i figured the bonds broken are: 1 C triple bond C 1(812kj/mol) 2 C-H 2(414kj/mol) 1 H-H 1(435kj/mol) Bonds formed 1 C=C 1(590kj/mol) 4 C-H 4(435kj/mol) Is this right
Wednesday, November 12, 2008 at 4:53pm by tomi

chemistry
use the following data, as appropriate, to estimate the molarity of a saturated aqueous solution of Sr(IO3)2. Molarity of a saturated aqueous solution of Sr(IO3)2 Sr(IO3)2(s) delt h kJ/mol=-1019.2 delta G kJ/mol=-855.1 delta S= 234 J mol-1K-1 Sr^2+(aq) delta h= -545.8 kJ/mol ...
Sunday, December 2, 2012 at 12:34am by Allyx3

chemistry
use the following data, as appropriate, to estimate the molarity of a saturated aqueous solution of Sr(IO3)2. Molarity of a saturated aqueous solution of Sr(IO3)2 Sr(IO3)2(s) delt h kJ/mol=-1019.2 delta G kJ/mol=-855.1 delta S= 234 J mol-1K-1 Sr^2+(aq) delta h= -545.8 kJ/mol ...
Sunday, December 2, 2012 at 11:09am by Allyx3

Chemistry Check Please!
A solution is prepared by dissolving 3.44 g of sucrose, C12H22O11, in 118 g of water. a) What is the molality of the resulting solution? b) What is the mole fraction of water in this solution? B) moles of h2o=118g/18(g/mol)=6.5556 mol moles of c12h22O11= 3.44g/342.3(g/mol)=0....
Thursday, January 16, 2014 at 1:19am by Kate

chemistry
Tetraphosphorus trisulphide (P4S3) is used in the match heads of some matches. It is produced in the reaction 8P4+3S8 --> 8P4S3. Determine which of the following statements are incorrect, and rewrite the incorrect statements to make them correct. a. 4 mol P4 reacts with 1.5...
Tuesday, April 6, 2010 at 5:12pm by Ana

Chemistry
I need help I can't seem to get the right answer. Please help! 1/2 H_2 (g) + 1/2 Cl_2 (g) --> HCl (g) -92.3 kJ/mol Na(s) + 1/2 O_2(g) + 1/2H_2(g) --> NaOH(s) -426.8 kJ/mol NaCl(s) --> Na(s) + 1/2Cl_2(g) 411.1 kJ/mol H_2O(l) -->H_2(g) + 1/2O_2(g) 285.8 kJ/mol HCl(g...
Friday, November 8, 2013 at 9:22pm by Alex

Chemistry
the activation energy for the decomposition of HI(g) to H2(g) and I2(g) is 186kj/mol. the rate constant at 555k is 3.42 x 10^-7 L/mol*s. What is the rate constant at 645K? Please show all steps USING THE ARRHENIUS EQUATION. Here is my work so far: K = A e^(-Ea/RT) 3.52 x 10^-...
Tuesday, October 26, 2010 at 9:00pm by Jim

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