59,039 results, page 3

  1. Chemistry A.P.

    Hi there, I need some help with my homework problem for chemistry, What is the balanced thermochemical equation for glucose (C6H12O6) and O2 gas form CO2 gas and liquid water?
  2. Chemistry

    What is the chemistry behind caffeine extraction with Na2SO4, CH2CL2 and NaCO3. I know that Na2SO4 some how aborbs the water from a solution leaving the undissolved soilds or something...
  3. Chemistry

    In studying the chemistry and qualitative analysis of anions, why wouldn't HCl be a good acid to use to determine the solubility of a silver precipitate in acid solution?
  4. Chemistry Help Please!!

    What effect would a sweaty person have on the pool chemistry? Would the reaction tend to be forced to the right or to the left? Any help is greatly appreciated!
  5. Chemistry

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

    Do you think that there is a high correlation between proficiency in mathematics and proficiency in chemistry? Explain why or why not. Use details about the components of each field to support your answer.
  7. Chemistry

    List three advantages and three disadvantages of improvised apparatus in teaching chemistry?

    1.Chemistry Question: A 0.1 M solution of acetic acid is titrated with 0.05M solution of NaOH. What is the pH when 60% of the acid has been neutralized? The equilibrium constant (Ka) for acetic acid is 1.8x10^-5 2. Chemistry question: On average, how far is a molecule of air ...
  9. Chemistry

    Calculate the standard free-energy change for the following reaction at 25 C degrees. 2Au^3+(aq)+3Ni(s) <-- --> 2Au(s)+3Ni^2+(aq) Ni2+(aq) + 2e- -> Ni(s) E=-0.26 Au3+(aq) + 3e- -> Au(s) E=+1.498 G= ? KJ Would it be G=1.758? •Chemistry - DrBob222, Sunday, March 31...
  10. Chemistry

    1. Chemistry is the study of the composition, structure and properties of substances.- F? 21. Which is found in the nucleus-- Protons or neutrons? 27. Copper metal is: a. poor conductors b. brittle c. malleable C? 44. What is the charge on most polyatomic ions? - Negative ...
  11. Chemistry

    what number should be placed in the blank to balance the equation C 3 H 8 + 50 2 --> 3 CO 2 ___ H 2 O I have been working on this Q for four hours and it is driving me CRAZY please HELP i hate chemistry or anything with numbers in it as a matter of fact.
  12. chemistry

    can someone explain the leveling effect in chemistry or provide a good link please? in my chem book it says something like HNO3<H2SO4<HCl<HBr<HI<HClO4 but i don't get why they are greater/smaller
  13. Chemistry

    This is for grade 11 chemistry, balancing equations. Help asap? I'd like to get it done by tonight, if possible. Type of reaction: Predict product in words: Write Balance equation: Heres the question. Aluminum+ Zinc Sulfide =
  14. General Chemistry Project Ideas?

    Hi I'm a high school science teacher and I teach General Chemistry when we learn how chemistry relates to our everyday lives. Right now were learning about some common compounds. I need projects ideas regarding some common compounds relating to their everyday lives.
  15. Chemistry

    Chemistry - Danielle , Wednesday, February 11, 2009 at 7:24pm The density of a 22.0% by mass ethylene glycol (C2H6O2) solution in water is 1.03 g/mL. Find the molarity of the solution. Answer in M
  16. Dr.Bob - Question

    I'm know I'm interested in the chemistry field. The problem is that I have to further narrow down my field of interest. I was curious to know what type of chemistry did you specialize in in the past. -christina
  17. Chemistry-Dr. Bob

    Please help me in any way to relate the concepts of how heat, solutions,equillibrium, nuclear and organic chemistry are interrelated. I appreciate any direction or info you could provide, Dr. Bob Thank you
  18. chemistry ............chemistry

    if you had to design a firework show for a Christmas celebration , what elements would you include in the fireworks ? why ? I knew u post answer for me , but i can't find it . May you answer for me? Thank you so much !!
  19. physical chemistry

    This question is about a lab called Heats of Ionic Reaction in my Physical Chemistry class. I need to know why there should be a large percentage error in deltaH4
  20. Chemistry

    Can someone please tell me what to expect from Beginner High School chemistry? Is it mostly applying mathematics like physics? Or basically memorizing like biology? Thank you!
  21. Chemistry

    Where can i find the quanity measured by each of of the seven SI base units and the SI symbol of the unit. Here: thanks
  22. chemistry

    What is the hydrogen ion concentration, in mol dm−3, when 2.00 g of sulfuric acid is dissolved in water to give 0.400 dm3 of solution? could you explain in a simple and clear way please because im not very good at chemistry. thanks in advance
  23. AP Chemistry

    What is meant by minimum and maximum energy problems. Are there different equations to find them. What does this conceptually mean? * This is dealing with quantum chemistry such as plancks equation, and debroglie equation.
  24. chemistry

    There is a ball with a mass of 1000 lbs. It's turned into wire with a diameter of 3.12 x 10^-1 How long is the wire? This is my crazy chemistry teacher's idea of a test...and I don't even think there's a solution. HELP ME
  25. Chemistry

    What volume would be occupied at 0°C and 1 atm by 3 mol CO₂(g)? I just might need someone to help me work this out, I would greatly appreciate it! I don't understand this chemistry problem.
  26. chemistry

    Moles chemistry? Calculate the mass of solute required to prepare ib the solution 200cm^3 of solution containig 0.50 mol dm ^-3 cl-iond prepared by dissolving cacl2.6h2o in water.
  27. Chemistry

    Name 3 careers where you are required to know PHYSICAL Chemistry, and why those careers require it.
  28. chemistry ----------- chemistry

    on the atomic level , how are physical changes and chemical changes different ?

    how can different steps in the analytical process help in solving probs in Analytical Chemistry

    In the following sentence, which words should be in quotation marks? Did you read the chapter Chemical Reactions in our science textbook, Understanding Chemistry? A. chapter Chemical Reactions B. Chemical Reactions C. Understanding Chemistry I think the answer is B, as it is a...
  31. Choosing High School Courses

    I want to major in something English or History related, probably Secondary Education, International Studies, or Journalism. I am currently enrolled in chemistry and I am doing horribly. Would colleges rather see me take chemistry and get a bad grade, or would they prefer me ...
  32. To Chemistry students

    Our primary chemistry tutor has gone on a trip for about a week and a half. In the meantime, you should make good use of the tutorials here: Once there, you can make an account for yourself if you wish. You don't have to, but you can. This is an ...
  33. chemistry

    what is suspension in chemistry? will you please give me a very long explanation about it now.....? I really need it for my project.plz?????? Write your own long explaination, and I will be happy to critique it.
  34. Chemistry

    A 334-mL cylinder for use in chemistry lectures contains 5.225 g of helium at 23 C. How many grams of helium must be releasedto reduce the pressure to 75 atm assuming ideal gas behavior?
  35. As Chemistry

    A SAMPLE OF ANTIMONY, Ar=121.8, WAS ANALYSED AND WAS FOUND TO CONSIST OF 60% OF 121Sb AND ONE OTHER ISOTOPE. DETERMINE THE MASS NUMBER OF THE OTHER ISOTOPE IN THE SAMPLE OF ANTIMONY. please help I'm really stuck, Chemistry - bobpursley Saturday, September 30, 2017 at 10:41am ...
  36. Chemistry

    Calculate the pH of a potassium phosphate buffer if the pKa of KH2PO4 is 7.2 and the acid-base ratio is 2:1 I took Chemistry 7 years ago and am in a review for a Biochem course I am takin. I do not remember the basics so any help with how to get started or what equations to ...
  37. chemistry class

    i have a Chemistry lab (level 2) final exam soon. our teacher told us that we would have % transmittance problems, can someone show me an examples (maybe from an online test) or a made up one, of what i might expect to find on my chemistry lab final? like an examples of a % ...
  38. chemistry

    Products are often marketed as "organic" or "natural". What do these terms mean when applied to consumer goods? Discuss how these terms may be used to mislead a public that is not knowledgeable in chemistry. Support your opinion with references.
  39. organic Chemistry

    In my Organic chemistry lab, the calculated enantiomeric excess was over 100% . Is this possible? and If not, what sort of error could have been made? *the observed optical rotation was read correctly
  40. College Chemistry

    This is my first time taking chemistry and I am VERY confused on the steps foe this problem! Kilocalories to condense 82g of steam at 100 degress C, cool the liquid and freeze it at 0 degress C.
  41. chemistry ......chemistry

    what does Planck mean when he states that energy in quantized? Ans: plank's theory proposes that the energies absorbed or emitted by atoms are quantized ,which means that their values are restricted to certain quantities. is this O.K?
  42. chemistry to MathMate

    Chemistry - CJ, Tuesday, March 31, 2015 at 10:53pm I am experiencing a major block.... I can't say.... 1micrometer= 1000nm 5micrometer= x..... because I'll get back the same thing So please help me, tell me the answer please.
  43. math sets

    out of 320 students at a university,190 taking math,235 taking chemistry and 120 taking physics.125 are taking both chemistry and math,95 taking both chemistry AND PHYSIC,55 TAKING BOTH MATH AND PHYSICS.HOW MANY ARE TAKING ALL THE THREE SUBJECTS
  44. SAT Math

    All of the students who took chemistry at Groveton High School last year were juniors or seniors, as shown in the table below. If 80% of the students who took chemistry passed, then what fraction of the students in the combined junior and senior classes took chemistry? Class ...
  45. Chemistry

    I need to be able to tie in acetic acid and boric acid. To decipher properties of acid-base chemistry and how they adhere to Le Chatelier’s principle. I appreciate any input....
  46. chemistry

    Maxine is studying about electrolytes in her chemistry class. The teacher asks her to test 4 different solutions to determine how well each one conducts electricity. which solution will best conduct electric current? a) HC2H3O2 b) C2H5OH c) KOH d) H2O2
  47. Chemistry

    Maxine is studying about electrolytes in her chemistry class. The teacher asks her to test 4 different solutions to determine how well each one conducts electricity. which solution will best conduct electric current? a) HC2H3O2 b) C2H5OH c) KOH d) H2O2
  48. chemistry+reply

    can someone reply to my previous chemistry thread please?
  49. Chemistry- volumn

    chemistry: 50mL HNO3 + 50.5mL HaOH = volumn?
  50. PLZ look at Chemistry Questions!!!

    No chemistry questions are getting answered =(
  51. Chemistry

    Chemistry - MathMate, Tuesday, March 31, 2015 at 2:56pm 1m = 1000 mm (millimeter) 1 mm = 1000 μm (micrometer) 1 μ = 1000 nm (nanometer) If the tube is 1 nm in diameter, then veryify that 5 μm = 5*1000 nm = 5000 nm = how many diameters? Chemistry - MathMate, ...
  52. Maths

    In a survey of 200 students of a school, it was found that 60% study mathematics, 45% study physics, 35% study chemistry, 20% study mathematics and physics, 15% study physics and chemistry, 25% study chemistry and mathematics and 10% none of these subjects. Find the number of ...
  53. Chemistry

    Please help me with this chemistry question? I am working on a lab report and I am stuck on this question: Use the concept of stoichiometry to explain why balanaced equations are necessary when performing calculations in chemistry. Propose a situation where precise amounts of ...
  54. Chemistry(Please respond)

    Calculate the pH of an aqueous solution of 0.15 M potassium carbonate. I know that pH = -log(H30+) but I am not sure how to start this problem. Chemistry(Please help) - DrBob222, Saturday, April 14, 2012 at 11:09pm Hydrolyze the CO3^2-. CO3^- + HOH ==> HCO3^- + OH^- Do an ...
  55. Chemistry 130

    Can someone please help me with this question? Could freezing point depression be used for substances that are not soluble in water? Please help me....can you explain why? Is there anywhere I can find this information because my chemistry book doesn't have any info. about this...
  56. math

    In a class of 50 student, 25 offer mathematics, 22 offer physcis, 30 offer chemistry and all the student take at least one of these subjects , 10 offer physics and mathematics, 8 offer chemistry and mathematics , 16 offer physics and chemistry. (a) draw a venn diagram to ...
  57. Chemistry

    Look up the solubility of NaCl in both water and ethanol (in the CRC handbook of chemistry which i don't have access to, and any help would be appreciated) Consider the dissolution process, and competing intermolecular forces to account for the observed differences in solubility.
  58. Chemistry

    Look up the solubility of NaCl in both water and ethanol (in the CRC handbook of chemistry which i don't have access to, and any help would be appreciated) Consider the dissolution process, and competing intermolecular forces to account for the observed differences in solubility.
  59. Chemistry

    what volume of ammonia gas will be produced when 1.26L of nitrogen react completely in the following equation? N2 + 3H2 > 2NH3 Please if someone can just give me the order of operation it will be much appreciated because chemistry is just not my forte.
  60. chemistry

    A 1.00L sample of a gas has a mass of 1.92g at STP. What is the molar mass of the gas? (This is a question on my chemistry worksheet, and I can't find the answer in my book.)
  61. chemistry

    The actual chemistry question was, given that there are 4.19 g of C6H6 how many moles do you have and this is how I solved it and it was wrong. 4.19g/78g/mole = .054 moles of C6H6
  62. maths

    in a class of 35 students twice as many study chemistry and study physics half a many study chemistry as study both subjects illustrate it on a venn diagram
  63. Chemistry

    The chemistry problem is "How would you make 500.0 mL of a 3.00 M HCl solution form a stock solution that is 6.00 M?" I have no clue how to even approach this problem.
  64. Chemistry

    From the Standard Potential Table in your general chemistry textbook: Which reaction has been chosen as the 'standard' against which every other reaction is measured? A. 2H+ + 2e– ==> H2 B. O2 + 4H+ + 4e– ==> 2H2O C. F2 + 2e– ==> 2F– D. Li+ + e– ==> Li E...
  65. chemistry

    hi Dr Bob..can you please help me with this chemistry problem? I got problem dealing with the chemical formula.How i want to find the number of moles of 2g of Fe(NH4)2(SO4)2.6H2O???please help me.Thank you
  66. chemistry

    A student is asked to prepare 250.0 mL of 3.5 M copper (II) sulfate from solid copper (II) sulfate pentahydrate. Describe how this solution should be made in the chemistry laboratory.
  67. chemistry

    A chemistry experiment needed 12.45 grams of chemical to produce one liter of a gas. If Zoe wanted 24 liters of gas, how many kilograms of the chemical will she need?
  68. Chemistry

    I have a gr 10 chemistry unit test coming up can someone please refresh my mind on this unit? and tell me what things i should practice for the test? Tyy
  69. Chemistry

    List the total number of each type of atoms in the following reactants. A) 2HCL + Ca(OH)2 = 6 hydrogen, 2 carbon, 2 lithium, 2 calsium, 4 oxygen B) 2Na3PO3 + 3Ca(NO3)2 This one is a bit more complicated. May any chemistry teacher show me how to do this. Thank you very much in ...
  70. honors chemistry- isotopes...

    can scientists actually measure the mass and relative abundance of isotopes of an element by counting each particle and measuring their masses? [ i think no because it would be too small ] if not, how could a scientist measure the mass and relative abundance of isotopes of an ...
  71. Chemistry

    Why are numbers used in chemistry often expressed in scientific notation? They otten are very large or very small. Printing those types of numbers is onerous.
  72. Chemistry

    In chemistry, how is a monomer related to a polymer? Think of a chain: Each link is a monometer, as the links are joined, you have a chain which represents the polymer.
  73. Chemistry/pH- Weak Acid

    in response to Chemistry/pH- Weak Acid. but the rule of 5%? 0,0100/(1.00x10^-4) =100% The aproximation you do is not valid...or? Ka= (1,0*10^(-4))^2/(x-1*10^(-4) )=1,00*10^(-6)....I got c=0,0101M :-(
  74. chemistry, organic chemistry

    How do we calculate the temperature of a mixture of hexane and heptane at which the mixture solution equals 1atm?This will be the boiling point of the solution
  75. Math

    Lee has two tests to study for: Chemistry and French. She plans to study for up to 13h in total. She will spend at least 4 hours studying Chemistry and up to 6 hours studying French. Let x represent the number of hours she will spend studying Chemistry, and y the number of ...
  76. chemistry(check my answer)

    From the Standard Potential Table in your general chemistry textbook: Which reaction has been chosen as the 'standard' against which every other reaction is measured? A. 2H+ + 2e–H2 B. Li+ + e–Li C. O2 + 4H+ + 4e–2H2O D. F2 + 2e–2F– E. H2 + 2e–2H– is it A
  77. Chemistry

    A chemistry lab experiment requires 34.0 g of silver nitrate. How many grams of a 23.1% by mass solution of silver nitrate should be used?
  78. chemistry project please help really need it

    help me out in choosing a topic for my project it should be anyhow related to chemistry help me please
  79. Chemistry

    I was given extra credit to find who Le Châtelier's High School Principal was. Not his PrincipLE, but his PrincipAL. My chemistry teacher told us only one student of his out of all these years came with the answer. Think outside of the box. Thanks.
  80. Chemistry

    I was given extra credit to find who Le Châtelier's High School Principal was. Not his PrincipLE, but his PrincipAL. My chemistry teacher told us only one student of his out of all these years came with the answer. Think outside of the box. Thanks.
  81. Chemistry

    I have a question in chemistry about combining compounds. I didn't really understand from my teacher. I have to combine Pb(NO3)2 with Na4OH. Also combine CaCl2 with Na2SO4. Can someone explain.
  82. Experimental Chemistry

    (Experiments in synthetic chemistry) For heating under reflux, must the solvent level in the round bottomed flask be above the oil level (in the hot oil bath)? Why? Thanks.
  83. Chemistry

    Can someone please help me solve this homework problem for my chemistry class.It's my last problem and I'm stuck!:/ Thanks :) A 4.0*10^1kg sample of water absorbs 308KJ of heat. If the water was initially at 25.5 C, what is its final temperature?

    Does anyone have a "Chemistry in Context 6th edition" by mcgraw and hill book? I don't have one and my homework is in there. Page 30, questions 5,6 & 7. If you could, type out the questions for me that would be a HUGE help.
  85. Chemistry

    I keep reading that lead is a poor electrical conductor, but I would like to know the chemistry of why exactly it is a poor conductor.
  86. Chemistry

    Is there a chemistry teacher for jiskha? Or someone that knows what my teacher is talking about? :’( He wants me to: Calculate the number of moles of CO2 in 63.0g of CO2
  87. Chemistry

    I did a lab in chemistry about weighing table salt and sand and mixing it with water and pouring it through a funnel. One of my lab quetions was, What are some possible sources of error in this activity? First of all, I don't know what this question means. Can anyone please ...
  88. Chemistry

    Although I do very well in chemistry I never really understood converting units. Perform each of the following conversions. A. 8.43cm to millimeters B. 2.41x10^2cm to meters C. 294.5nm to cm D. 1.445x10^4m to kilometers E. 235.3m to millimeters F. 903.3nm to micrometers
  89. Chemistry(Please check)

    1) The Ka for acetic acid is 1.8e-5. What is the pH of a 3.18M solution of this acid? I did 1.8e-5 = x^2/3.18 x=sqrt 1.8e-5 X 3.18 = 7.56e-3 pH=-log(7.56e-3) = 2.12 The pH is 2.12 2) At 25 degrees celsius, the pH of a 1.75M NaCN solution (the Ka for HCN is 4.0e-10) is ? 4.0e-...
  90. To Ron: Chemistry 12

    I've deleted your 14 chemistry questions because you've made no attempt at answering them. This is not a site to dump homework questions like so much garbage to be disposed of. If you'd like to repost any of them with your answers, someone may be able to check them.
  91. General Chemistry

    The four quantum numbers for the last electron placed in the orbitals of a certain element are: n=3 l=2 m of l=0 and m of s=-1/2. What is the element? I need help with this part of chemistry I have NEVER understood this ever. I know how to do the configurations but not this. I...
  92. chemistry

    A chemistry student weighs out 0.0294g of sulfurous acid H2SO3 , a diprotic acid, into a 250.mL volumetric flask and dilutes to the mark with distilled water. He plans to titrate the acid with 0.2000M NaOH solution.
  93. Chemistry

    Fluorine reacts with oxygen to yield oxygen difluoride. 2 F2(g) + O2(g)<--> 2 OF2(g) What is the value of K if the following concentrations are found at equilibrium: [O2]= 0.200 mol/L, [F2]=0.0100 mol/L, and [OF2]=0.0633 mol/L Chemistry - DrBob222, Thursday, March 1, ...
  94. chemistry

    A certain monoprotic weak acid with Ka = 6.7 × 10-8 can be used in various industrial processes, but is no longer used in chemistry teaching labs because it tends to explode when it gets old. (a) What is the [H+] for a 0.558 M aqueous solution of this acid and (b) what is its...
  95. strayer

    You and three (3) of your friends were in the same advance placement high school chemistry class in high school. All four (4) of you decided to take the same chemistry class together at the local university along with 21 other students. On the first day of class, the professor...
  96. Chemistry

    chemistry question. How many grams of silver sulfide can be produced by heating 45 grams of silver excess sulfer?
  97. chemistry

    Carbon and silicon are both in Group 14 of the periodic table. (i) Identify compounds which illustrate similarities in the chemistry of carbon and silicon. (ii)Identify compounds which illustrate significant differences in the chemistry of carbon and silicon. Hence explain why...
  98. chemistry(oxidation)

    ok,I really don't understand the whole oxidation numbers thing my question is state the oxidation number for nitrogen in the following NH3= -3 NO2-1= -1 N2= 0 NO2Cl= 5 N2H4 -2 am I correct? NH3= -3 NO2-1= -1 No, oxygen is -2, so N is +3 N2= 0 NO2Cl= 5 N2H4 -2 http://www....
  99. math

    Mrs. Gomes found that 40% of students at her high school take chemistry. She randomly surveys 12 students. What is the probability that at most 4 students have taken chemistry? Round the answer to the nearest thousandth. A)0.008 B)0.438 C)0.562 D)0.665
  100. chemistry

    calculate the volume of 2.27 M Nal that would be needed to precipitate all the of the Hg +2ion from 166mL of a 2.08 M Hg(NO3)2 The equation for the reaction is 2 Nal(aq) + Hg(NO3)2(aq) > HgI2(s) + 2 NaNO3(aq) Please Help I'm really having trouble understanding organic ...
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