# college chemistry

Popular questions
1. ## College Chemistry

I balanced the equation: HBr(aq) +NH3(aq)->NH4Br I need to find the ionic equation and the net ionic equation

asked by KELLY on October 3, 2010
2. ## college chemistry

How many total moles of ions are released when the following sample dissolves completely in water: 5.15x10^-3 g Ca(NO3)2

asked by KELLY on September 26, 2010
3. ## College Chemistry

Write formation reactions for the following. (You must include the states of matter for each atom or compound) A. Ca(NO3)2 (s) B. CH3OH (l) C. NaClO4(s)

asked by Bekah on October 25, 2011
4. ## college chemistry

if 2.00g of Zn is allowed to react with 2.00g of CuSO4 according to the equation CuSO4(aq) + Zn(s)-----> ZnSO4 (aq)+ Cu(s) how many grams of Zn will remain after the reaction is complete ?

asked by isabel on November 5, 2012
5. ## College Chemistry

Amphetamine (C9H13N) is a weak base with a pKb of 4.2. Calculate the pH of a solution containing an amphetamine concentration of 215 mg/L. I calculated the molarity as 1.58*10^-3 and the Ka as 1.58*10^-10. I did ICE and i got the pH as 6.3, but it was

asked by Kyle on March 23, 2010
6. ## college chemistry

Calculate the pH of the cathode compartment for the following reaction given Ecell = 3.01 V when [Cr3+] = 0.15 M, [Al3+] = 0.30 M, and [Cr2O72-] = 0.55 M. 2 Al(s) + Cr2O72-(aq) + 14 H+(aq) → 2 Al3+(aq) + 2 Cr3+(aq) + 7 H2O(l)

asked by Anonymous on May 20, 2015
7. ## College Chemistry

Consider the reaction. 4Fe(s) + 3O2(g) ¨ 2Fe2O3(s) If 0.500 mol of Fe reacts with 0.400 mol of O2, what are the limiting reactant and the theoretical yield in moles of Fe2O3 for the reaction, respectively?

asked by Lisa on March 26, 2012
8. ## college chemistry

From your mass of MgNH4PO4.6H2O collected, calculate your value a) for the mass of "P2O5" in the initial mass of fertilizer analyzed b) the % "P2O5" in the fertilizer. Compare this with the manufacturer's specification. Just want to know how i would go

asked by ali on September 23, 2015
9. ## College Chemistry

Calculate the ratio of NaF to HF required to create a buffer with pH=3.95. Also, can you please explain in a nutshell the whole concept of buffers? Thanks!

asked by Katie on March 23, 2010
10. ## College Chemistry

How many milliliters of 0.100 M HNO3 are needed to neutralize the following solutions? A. 45.0 mL of 0.667 M KOH B. 58.5 mL of 0.0100 M Al(OH)3

asked by Bekah on October 6, 2011
11. ## College Chemistry

Suppose there are two known compounds containing the generic elements X and Y. You have a 1.00-g sample of each compound. One sample contains 0.29 g of X and the other contains 0.38 g of X. Identify plausible sets of formulas for these two compounds. Check

asked by Christina on September 3, 2014
12. ## college chemistry

Carbon monoxide is toxic because it bonds much more strongly to the iron in hemoglobin (Hgb) than does O2. Consider the following reactions and approximate free energy changes: Hgb + O2 ---> HgbO2 ∆G⁰ = -70 kJ Hgb + CO ---> HgbCO ∆G⁰ = -80 kJ Using

asked by Stephanie on April 28, 2010
13. ## College Chemistry

H2C=C=CH2 molecule is linear, what are they hybridization states of the carbon atoms? draw diagrams to show sigma and pi bonds.

asked by George on May 8, 2011
14. ## college chemistry

When a 5.00-g sample of KCN is dissolved in water in a calorimeter that has a total heat capacity of 2.642 kJ·K–1, the temperature decreases by 0.340 K. Calculate the molar heat of solution of KCN.

asked by wisa bedalie on October 18, 2014
15. ## College Chemistry

Please tell me what I did wrong on this problem: Given the equation Fe2O3(s)+3CO(g)→2Fe(s)+3CO2(g), Calculate the number of grams of CO that can react with 0.370kg of Fe2O3 Here's what I did: .370kg x 1000 = 370g of Fe2O3 370g/[(55.85 x 2) + (13 x 3)] =

asked by Theresa on November 1, 2014
16. ## college chemistry

solid diarsenic trioxide reacts with Flourine gas to produce liquid arsenic pentaflouride and oxygen gas. Write the Qc for this reaction

asked by Mia on March 24, 2015
17. ## College Chemistry

Determine the concentrations of MgCl2, Mg2+, and Cl- in a solution prepared by dissolving 2.39 x 10^-4g MgCl2 in 2.50L of water. Express all three concentrations in molarity. Also display the concentrations of ionic species in part per million (ppm).

asked by Bailey on September 20, 2016
18. ## College Chemistry

Balance this equations for redox reactions in basic solution. Fe(OH)3(s) + OCl- ¨ FeO42- + Cl-

asked by Marissa on September 23, 2010
19. ## College Chemistry

A Galvanic cell consists of Mg electrode in a 1.0 mol L -1 Mg(NO3)2 solution and a Ag electrode in a 1.0 mol L-1 AgNO3 solution. Calculate standard emf for the spontaneous reaction of this electrochemical cell at 25 C, given that the standard reduction

asked by Elleni on October 27, 2010
20. ## college chemistry

When ammonium carbonate decomposes, what would happen to a glowing splint in the presence of the gases that are evolved. Explain

asked by jennifer on April 3, 2011
21. ## college chemistry

From your mass of MgNH4PO4.6H2O collected, calculate your value a) for the mass of "P2O5" in the initial mass of fertilizer analyzed b) the % "P2O5" in the fertilizer. Compare this with the manufacturer's specification. Just want to know how i would go

asked by ali on September 23, 2015
22. ## College Chemistry

A student placed 14.0g of glucose (C6H1206) in a volumetric flask, added enough water to dissolve the glucose by swirling, then carefully added additional water until the 100.-mL mark on the neck of the flask was reached. The flask was then shaken until

asked by Christian Gillard on February 21, 2010
23. ## College Chemistry

Calculate the heat of formation reaction for SiO2(s)+4HF(g) --> SiF4(g)+2H2O(l) I got -129.6 and it says I'm wrong

asked by Kaylene on February 28, 2010
24. ## College Chemistry

In this lab: we demonstrated the method of evaporation of a saturated sodium chloride solution. The following question ask: 1) why is sodium chloride chosen for the solute? 2)Suggest reasons why the following were not chosen for the solute? a)Calcium

asked by Tim on September 4, 2010
25. ## college chemistry

To dilute a solution from 0.600 M to 0.100 M, the final volume must be A. 1/6 the original volume. B. 0.7 L. C. More information is needed to answer this question. D. 6 times the original volume. E. 60 L.

asked by Jake on November 18, 2010
26. ## College Chemistry

When one mole of C6H6 is burned, 3.27 MJ of heat is produced. When the heat from burning 5.43 g of C6H6 is added to 5.69 kg of water at 21.0°C, what is the final temperature of the water?

asked by Shannon on September 15, 2015
27. ## College Chemistry

Assuming that Ka is 1.85 *10-5 for acetic acid, calculate the pH at one-half the equivalence point and at the equivalence point for titration of 50mL of 0.100M acetic acid with 0.100M NaOH.

asked by Kenetria on October 14, 2012
28. ## College Chemistry

The following data are obtained for the decomposition of N2O5 at a certain temperature: 2N2O5(g)↔4NO2(g) + O2(g) Time(s) 0 200 400 600 800 N2O5 (atm) 2.10 1.85 1.63 1.43 1.26 Find the rate constant kobs for this first-order decomposition reaction in

asked by cara on February 6, 2011
29. ## College Chemistry

Which of the following ions possess a dipole moment: ClF2+, ClF2-, IF2+, or IF4-?

asked by Anita on May 8, 2011
30. ## college chemistry

Dry ice is solid carbon dioxide. Instead of melting, solid carbon dioxide sublimes according to the following equation: CO2(s)--> CO2(g). When dry ice is added to warm water, heat from the water causes the dry ice to sublime more quickly. The evaporating

asked by Eddie on November 9, 2009
31. ## college chemistry

The base dissociation equilibrium constant (Kb) for C5H5N is 1.40×10-9 (eq. 1). (eq. 1): C5H5N(aq) + H2O(l) = OH-(aq) + C5H5NH+(aq) Calculate the value of the equilibrium constant (Ka) for the hydrolysis of C5H5NH+ as shown in the reaction (eq. 2). (eq.

asked by sparkle on November 4, 2010
32. ## college chemistry

Given that the heat of fusion of water is -6.02 kJ/mol, that the heat capacity of H2O(l) is 75.2 kJ/mol*K and that the heat capacity of H2O(s) is 37.7 kJ/mol*K, calculate the heat of fusion of water at -11 K.

asked by i'm stuck on January 24, 2010
33. ## College Chemistry

a 1.00-L solution saturated at 25°C with calcium oxalate (CaC2O4) contains 0.0061 g of CaC2O4. The solubility constant (Ksp) for this salt is [CaC2o4= 128.09 g/mol] a) 6x10^ -3 b) 4.6x10^ -8 c) 2.3x10^ -9 d) 1.5x10^-4 if you could please work it out for

asked by Shanice on December 2, 2010
34. ## College chemistry

Butane (C4H10) has a heat of vaporization of 22.44 kJ/mol and a normal boiling point of -0.4 C. A 250 mL sealed flask contains 0.5 g of butane at -22 C. How much butane is present as a liquid? If the butane is warmed to 25 C, how much is present as a

asked by I NEED HELP! on January 23, 2010
35. ## College Chemistry

A buffer solution contains 0.120M acetic acid and 0.150M sodium acetate. a. How many moles of acetic acid and sodium acetate are present in 50.0 ml of solution? b. if we add 5.55 mL of 0.092M NaOH to the solution in part (a) how many moles of acetic acid ,

asked by Elizabeth on November 10, 2010
36. ## college chemistry

The equilibrium constant for the reaction Sr(s) + Mg2+(aq) Sr2+(aq) +Mg(s) is 3.69 x 10^17 at 25 C. Calculate Ecell for a cell made up of Sr/Sr2+ and Mg/Mg2+ half cells.

asked by danielle on April 12, 2017
37. ## College Chemistry

For each trial, enter the amount of heat lost by the calorimeter, qcalorimeter. Be careful of the algebraic sign here and remember that the change in temperature is equal to the final temperature minus the initial temperature. Report your answer using 4

asked by Jose on April 12, 2013
38. ## college chemistry

CH4 + 2 Cl2--> CH2Cl2 + 2HCl Cl-Cl bond energy: 242 kj/mole 1. Calculate the amount of energy (Joules) needed to break a single Cl-Cl bond. 2. Calculate the longest wavelength of light (meters)that can supply the energy per photon necessary to break the

asked by Anonymous on March 31, 2010
39. ## college chemistry

. One possible use for the cooking fat left over after making french fries is to burn it as fuel. Formula (for cooking fat) = C51H88O6 Density = 0.94 g/ml ΔH°f = - 1310 kJ/mol. Write a balanced equation of the combustion of cooking fat (the products are

asked by George on April 17, 2010
40. ## college chemistry

calculate the average kinetic energies of CH4 and N2 molecules at 273k and 546k

asked by Ellie on January 20, 2015
41. ## college chemistry

The solvay process in an industrial method for preparing baking soda. In the process, CO2, NH3, H2O, and NaCl react to produce NaHCO3. If 25.0 L of carbon dioxide gas at STP and 20.0 L of ammonia gas at STP react in excess water and salt, what is the mass

asked by Ana g on April 15, 2012
42. ## college chemistry

When a solution containing 8.00 g NaOH in 50.0 g of water at 25 °C is added to a solution of 8.00 g of HCl in 250.0 g of water at 25 °C in a calorimeter, the temperature of the solution increases to 33.5 °C. Assuming that the specific heat heat of the

asked by Karla on June 23, 2015
43. ## college chemistry

Balance the equation in aqueous acidic solution: C2O42-(aq) + MnO4-(aq) → Mn2+(aq) + CO2(g) please teach me how to do it!

asked by sparkle on November 4, 2010
44. ## college chemistry

Please identify the net ionic equation for Na3PO4 +ZnSO4=Zn3(PO4)2+ Na2SO4

asked by Jessica on September 27, 2010
45. ## College Chemistry

Based on a Kc value of 0.140 and the data table given, what are the equilibrium concentrations of XY, X, and Y, respectively?

asked by Anonymous on July 12, 2013
46. ## college Chemistry

An adult takes about 15 breaths per minute, with each breath having a volume of 500mL. if the air that is inhaled is "dry", but he exhaled air is 1 atm pressure is saturated with water vapor at 37 degree C(body temp), what mass of water is lost from the

asked by CM on October 19, 2008
47. ## College Chemistry

Given: 2Al2O3 (s) 4Al (s) + 3O2 (g) °H = 3351.4 kJ, what is °H for the formation of 12.50 g of aluminum oxide? Help please.

asked by Taylor Marie on March 20, 2010
48. ## College Chemistry

Consider the following reaction that occurs when natural gas is burned. CH4(g) + 2O2(g) ¨ CO2(g) + 2H2O(g) How many moles of water are produced when 6.2 mol of methane are burned? Assume that there is more than enough oxygen present.

asked by Lisa on March 26, 2012
49. ## college chemistry

If KHP sample #1 requires 27.30 mL of NaOH solution to reach an endpoint, what volume should be required for samples #2 and #3?

asked by Kristen on October 25, 2012
50. ## College Chemistry

here is the question: A sapphire gemstone contains 52.7% aluminum, 47.% oxygen, and traces of titanium. If the saoohire was found to contain 0.155g of oxygen, what is the mass of the gemstone? i think this is a precent unit factor but i don't know how to

asked by Jena on March 1, 2010
51. ## College Chemistry

a solution contains .25M Ni(NO3)2 and .25 M Cu(NO3)2. Can the metal ions be separated by slowly adding Na2CO3?Assume that for successful separation 99% of the metal ion must be precipitated before the other metal ion begins to precipitate, and assume no

asked by Jim on March 12, 2010
52. ## College Chemistry

how many liters of ethanol contain 1.5 kg of ethonal?

asked by Val on September 14, 2014
53. ## College Chemistry

Calculate the unknown of Ag+ if the potential of the following concentration cell is 300 mV at 25.0 C. Ag|Ag+(unknown)||Ag+(0.100M)|Ag I think I have to use Nernst Equation of Ecell=E0-.0592/nlogQ And at 25C is at 298K so i don't have to change anything. I

asked by Samantha on May 6, 2015
54. ## College Chemistry

Arrange the following compounds in the order of increasing Ksp: AgCl, AgBr, AgI. Explain your reasoning. I got AgI

asked by Anissa on May 6, 2015
55. ## College Chemistry

If a 375 mL sample of water was cooled from 37.5°C to 0°C, how much heat was lost (in joules)

asked by Esther on February 19, 2014
56. ## college chemistry

What is the entropy change for the vaporization of 2.6 mol H2O(§¤) at 100◦C and 1 atm? dH= 40700 J/mol Answer in units of J/K

asked by Samantha on November 19, 2010
57. ## College chemistry

How much heat (in kJ) is evolved in converting 1.00 mol of steam at 130.0 C to ice at -50.0 C? The heat capacity of steam is 2.01 J/g*C and of ice is 2.09 J/g*C.

asked by eddie on January 18, 2010
58. ## College chemistry

The pH of blood is 7.4 and that of saliva is 6.4. what is the difference in pH between these two solutions? How much more Hydronium ion (H3O+) is in the saliva than in the blood. I need a detailed answer with the formulas if you can. I have a hard time

asked by Liz on April 30, 2013
59. ## college chemistry

which of the following combinations is not suitable for making a buffer? h3po4 and nah2po4 na2co3 and nahco3 nh4cl and nh3 nah2po4 and na2hpo4 hclo4 and naclo4

asked by Cayla on April 30, 2012
60. ## College Chemistry

What are the concentrations of Pb2+ and Cu2+ when the cell potential falls to 0.370 V? Given: A voltaic cell consists of a Pb/Pb2+ half-cell and a Cu/Cu2+ half-cell at 25degrees C . The initial concentrations of Pb2+ and Cu2+ are 5.30×10−2 M and 1.60 M,

asked by Maria on June 23, 2012
61. ## College Chemistry

Calculate the pH of a 0.5 M Formic Acid (HCOOH) soln. ka= 0.00018

asked by Anonymous on November 4, 2010
62. ## College Chemistry

The Question Is: "A student weighs 0.347 g of KHP on a laboratory balance. The KHP was titrated with NaOH and the concentration of the NaOH determined to be 0.110 M. For the second titration, the student correctly diluted 6 M HCl from the reagent shelf

asked by James on October 19, 2010
63. ## college chemistry

Mg and O lab how will the relative number of moles of mg and o be affected if the following procedural errors are made? a)crucible is not brought to constant mass before the Mg is added. b)water is not added after the first heating of Mg, and the entire

asked by Anonymous on October 8, 2012
64. ## college chemistry

a 42 piece of ice at 0.0 C is added to a sample of water at 8.0 C. all of the ice melts and the temperature of the water decreases to 0.0 C. how many grams of water were in the sample.

asked by Linda on January 30, 2014
65. ## College Chemistry

A sample of an iron alloy contains 92.1g Fe, 2.59g C, and 1.59g Cr. Calculate the percent by mass of each component present in the alloy sample.

asked by Michelle on April 16, 2012
66. ## college chemistry

Consider only the species (at standard conditions) Na+, Cl-, Ag+, Ag, Zn++, Zn, Pb in ...? answering the following questions. Give reasons for your answers. a. Which is the strongest oxidizing agent? b. Which is the strongest reducing agent? c. Which

asked by Anonymous on May 20, 2015
67. ## College Chemistry

please help! You are given an unknown, colorless, solution that may contain only one salt from the following set: NaA, NaB, NaC. In solution each salt dissociates completely into the Na+ ion and the anion A-, B-, or C-, whose properties are A is green, B

asked by Marcus on November 10, 2010
68. ## College Chemistry

How much Ca(OH)2 is required to remove 90.0% of PO4^-3 from 7.5 times 10^6 L of drinking water containing 25 mg/l of PO4^-3?

asked by Emily on February 17, 2012
69. ## College Chemistry

The Cu2+ ions in this experiment are produced by the reaction of 1.0 g copper turnings with excess nitric acid. How many moles of Cu2+ are produced?

asked by Maggie on October 7, 2010
70. ## COLLEGE CHEMISTRY

write the net ionic equation (including phases) that corresponds to zn(no3)2 + Na2CO3--->ZnCO3+2NaNO3.

asked by Alex on February 17, 2017
71. ## College Chemistry

what is the approximate pH of a solution labeled 0.050 M HClO? I realized my mistake on my last post but this isnt a strong acid nor a strong base so how do i solve this?

asked by jahil on May 2, 2010
72. ## college Chemistry

Conductivity test, what controls the brightness of the light? (hint: think about your tapwater abd NaCl results and why they were different)

asked by judy on May 5, 2013
73. ## College Chemistry

The density of a 0.0122 M KMnO4 is 1.037 g/mL. Suppose 26.35 g of 0.0122 M KMnO4 are required to titrate 1.072 g of a household H2O2 solution. a)Calculate the mL of MnO4^- added to reach the endpoint. b)Calculate the moles of MnO4^- added to reach the

asked by Kelsey on February 25, 2014
74. ## college Chemistry

It requires 945.0 kJ/mol to break N2 molecules into atoms. Calculate the maximum wavelength of light that will still break these molecules apart. I tried converting the energy to kj and using E=hc/wavelength but that didn't give me the right answer...

asked by alexis on November 4, 2010
75. ## college chemistry

Comparing the boiling points of: A) C3H8 B) C5H12 C) C2H5OH and identify the folowing statements as either True or False: Dispersion forces only for (A) Boiling point (C) > Boiling point (A) (B) exhibits hydrogen bonding Boiling point (C) < Boiling point

asked by Stefanie on November 11, 2010
76. ## college Chemistry

Write a balanced equation for the dissolution of sodium carbonate (Na2CO3) in water. Find the number of moles of Na+ produced when 0.318 mol of sodium carbonate dissolves. Answer in units of mol.

asked by guy on January 24, 2009
77. ## College Chemistry

the acid dissociation constant for acetic acid is 1.85x10^-5. Calculate the pH at the equivalent point and the pH at one-half the equivalence point for the titration of 25.00 mL of 0.100 M acetic acid with 0.100 M NaOH?

asked by Courtney on October 18, 2015
78. ## college chemistry

Followed by the total volume. Calculate the molarity of this solution: 0.521 mol NaCl;125 mL

asked by michelle on April 16, 2012
79. ## college Chemistry

Why was there condensation of the beaker of cold water when a blue flame was passes underneath? This experiment is from the Gas Burner experiment. A) the product of carbon dioxide from combustion (B) the product of hydrogen dioxide from combustion (C) left

asked by Ivy on December 5, 2010
80. ## college chemistry

a 1.0kg sample of metal with a specific heat of 0.50KJ/Kg C is heated to 100.0C and then placed in a 50.0g sample of water at 20.0C . What is the final temperature of the metal and the water?

asked by Kylie on September 30, 2014
81. ## college chemistry

kilocalories released when 20.0 g of steam condenses at 100 degrees C. and the liquid cools to 0 degrees C.

asked by Linda on February 7, 2014
82. ## College Chemistry

calculate the moles of sulfuric acid that remained in the solution after reaction with the carbonate. the tared mass of carbonate is 1.5179g

asked by Anonymous on September 28, 2012
83. ## college chemistry

Rank from highest to lowest vapor pressure.CH3CH2CH2CH2OH,CH4,CH3CHCH2CH3CH3,CH3CH2CH2CH2CH3

asked by deb on August 31, 2012
84. ## college chemistry

If you start with 1.200 g of BaCl2 X(multiplied) 2H20 and heat if for 4-8 min, what will be the mass of the water removed?

asked by shirley on September 15, 2009
85. ## college chemistry

How do you calculate delta[S2O8 2-] in iodine clock reaction?

asked by vickie on March 31, 2010
86. ## College Chemistry

How many grams of steam and iron must react to produce 375g of magnetic iron oxide, Fe3So4

asked by Miguel on July 13, 2012
87. ## College Chemistry

If your heating generates soot on the bottom of the crucible, what is the origin of the soot? How will this soot collection affect x? x is the mols of waters of hydration

asked by Maggie on February 23, 2014
88. ## College Chemistry

Of KCl and NaCl, which has a higher lattice energy? What is lattice energy? Lost. Please help.

asked by Sally on October 24, 2010
89. ## College Chemistry

Complete the following table for aqueous solutions of caffeine, C8H10O2N4. Find: Molality Mass Percent Solvent Ppm Solute Given: Mole Fraction Solvent = 0.900 Molar Mass is 194.2g i believe.

asked by James on August 30, 2010
90. ## College Chemistry

Write a complete set of quantum numbers for the 5th electron added to H ion..(5th electron in any electron configuration). n= l= m(l)= m(s)=

asked by Anonymous on November 19, 2010
91. ## College Chemistry

A solution is saturated in both nitrogen gas and sodium iodide at 50 degrees C . When the solution is cooled to 25 degrees C what is most likely to occur?

asked by Brandy on March 23, 2014
92. ## college chemistry

Pentane, C5H12, and hexane, C6H14, combine to form an ideal solution. At 25⁰C the vapor pressure of pentane is 511 torr and that of hexane is 150 torr. In the vapor over a pentane-hexane solution at 25⁰C, the mole fraction of pentane is 0.15. What is

asked by Stephanie on April 28, 2010
93. ## college chemistry

When solutions of AgNO3 and NaOH react, the balanced molecular equation is 2AgNO3(aq) + 2NaOH(aq) Ag2O(s) + 2NaNO3(aq) + H2O(l) How much Ag2O is produced when 0.200 g of AgNO3 and 0.200 g of NaOH react?

asked by michelle on August 7, 2010
94. ## college chemistry

a)What is the mass of heavy water D2O produced when 5.20g of O2 reacts with excess D2? b)What is the mass of water H2O,produced when 5.20g of O2 reacts with excess H2 Consider the reaction 2D2+O2->2D2O Can someone step me through this?

asked by Amy on September 22, 2010
95. ## College Chemistry

Calculate the vapor pressure of a solution of 0.39 mol of cholesterol in 5.4 mol of toluene at 32oC. Pure toluene has a vapor pressure of 41 torr at 32oC.

asked by Molly on November 19, 2010
96. ## College Chemistry

A student weighs out 0.568 g of KHP (molar mass=204g/mol) and titrates to the equivalence point with (36.78 cm cubed which is 3) of a stock NaOH solution. What is concentration of stock NaOH solution? KHP is an acid with one acidic proton. The word cubed

asked by Elleni on October 22, 2010
97. ## college chemistry

How many megajoules are released when 9.0 gal of gasoline burns. how do I start to do this problem, and what are the steps to get there. thank you

asked by Linda on February 1, 2014
98. ## college chemistry

Please be specific! Briefly explain whether each if the following procedural errors would result in a high, low, or an unchanged calculated mass of Ca2+ in the analyzed tablet. a)a student had difficulty decanting the supernatant solution from the test

asked by anne on October 15, 2012
99. ## College Chemistry

A heat lamp produces 22.5 watts of power at a wavelength of 6.0 Mu.How many photons are emitted per second? (1watt= 1J/s )

asked by Kristen on February 4, 2012
100. ## college chemistry

exactly 11.2 ml of water at 23°c are added to a hot iron skillet. all of the water is converted into steam at 100°c. the mass of the pan is 1.5 kg and the molar heat capacity of iron is 25.19 j/(m·°c). what is the temperature change of the skillet

asked by eboni on October 22, 2013