chemistry! URGENT

61,442 results, page 22

  1. To all chemistry students

    Please understand that one of our chemistry tutors is on vacation this week. Please be patient.
  2. Chemistry

    The speed of sound is 3.40 times 10^4 cm/sec. What distance in meters can sound travel during a 48-minute chemistry lecture?
  3. chemistry

    If 35.0 g H2O at 22.7 °C is combined with 65.0 g H2O at 87.5 °C, what is the final temperature of the mixture? The specific heat capacity of water is 4.184 J/g×K. Chemistry
  4. Clinical Chemistry

    Anyone here good with clinical chemistry, particularly separation assays and high performance liquid chromatography?
  5. chemistry

    You have a solution of 12.0 M HCl. You need 36.5 g of hydrochloric acid for a reaction in your chemistry lab. How many mL of solution must you use?
  6. English

    Can you please check these sentences for me. It's really urgent. 1) Our science teachers are enthusiastic about your proposal of holding our first meeting in Italy. 2)However, prior to our meeting, the head of our science department would like to discuss the theme of our ...
  7. maths (variation)

    different questions pls! Very urgent! 1) the force E needed to make a machine pull,a load is partly constant and partly varies as the load to be pulled itself.when the load is 20g,the force needed is 1.4n,where as the force needed for 30g load is 2N. Find the: A)law connecting...
  8. Physics(URGENT!!!!)

    A ruler stands vertically against a wall. It is given a tiny impulse at θ=0∘ such that it starts falling down under the influence of gravity. You can consider that the initial angular velocity is very small so that ω(θ=0∘)=0. The ruler has mass m= 100 g and...
  9. Last chemistry post

    Can someone please reply to my previous post about chemistry preferable DrBob since he was helping me on it, but anyone is fine.
  10. chemistry

    i am doing a graph for my chemistry class, and i need help with excel. How do i plot 3.50X10^-3 into excel? it comes out as a negative number! help!
  11. Chemistry(Mastering Chemistry HELP )

    Convert 2.868*10^10g to kg, Mg, and mg For kg, I put .002868 and 2.868*10^-3 but the computer said neither are correct. HELP PLEASE! (:
  12. chemistry

    If 13.5 ml of concentrated (17.0 M) of sulfuric acid was spilled on the chemistry counter, calculate the mass of sodium bicarbonate needed to neutralize the acid
  13. Chemistry AP

    This isn't quite an HW question, I'm needing any site that gives practice Free Response problems for equilibrium for AP Chemistry if there are any for study and practice.
  14. chemistry

    If the gas could took a hemispherical shape, what circular surface area would the gas cover? chemistry
  15. Urgent! PLZZ HHEELLPP!!

    12.) Which of the following sentences uses a pronoun in the objective case? A. He just did an amazing magic trick. B. His sister said the solution is a secret. C. Please tell me how Mike did the trick! D. I wish I were as good a magician as Mike!**** 13.) Which sentence has ...
  16. Clarify (URGENT)

    In pairs (make sure you put both names on the answer sheet), create strategies and possible dialogue (min. 1 per topic) for communicating in the following situations: Saying no to sexual involvement Discussing whether or not to become sexually active Talking with a partner ...
  17. physics help needed very urgent !!!

    The block in the figure below lies on a horizontal frictionless surface and is attached to the free end of the spring, with a spring constant of 55 N/m. Initially, the spring is at its relaxed length and the block is stationary at position x = 0. Then an applied force with a ...
  18. Chemistry quistion help!

    I need help answer this question for a chemistry homework. What are the products in a reaction between an acid and a base? How can you tell that a reaction has occurred?
  19. Chemistry

    I just took my Chemistry midterm, and would like to know how to calculate my grade on the midterm with the curve. MEAN = 8.9 STANDARD DEVIATION = 2.9 MY SCORE = 7 Thank You!
  20. Chemistry

    How to do significant values in Chemistry? I am totally stuck; I have no idea what to do? My teacher gave me C due to the significant value error. Please help
  21. Chemistry

    I'm working on chemistry homework, and I just came across a few issues I don't understand. For one, why isn't Sodium Bromide NaBr2 (Online sources show it as NaBr)? Isn't Bromine a diatomic element?
  22. Chemistry Help - Check Please

    1) Describe 4 processes/forces that can explain all mechanism in Organic Chemistry? My answers: a) Electron Delocalization b) Hydrogen Bonding c) Aromacity d) Nucleophilic Substitution (SN1 & SN2) Thank you!

    Velocities of the 2 cars during the race are given in the tables below where velocities, v are in miles per hour and times t are in seconds. Sappho's car: time: 0 1 2 3 4 5 6 7 8 9 10 velocity:0 20 35 48 62 75 85 93 99 106 111 Homer's car: time: 0 1 2 3 4 5 6 7 8 9 10 velocity...
  24. Chemistry

    In chemistry, for a given substance what information links mass to moles? number of particles to moles?
  25. Chemistry - Forensics

    Discuss the chemistry of chemical reagents in forensics. Please be as specific and clear as possible. Thank you!
  26. Chemistry

    How is Surface catalyst(heterogeneous) and homogeneous catalyst different? I'm in 10th grade chemistry and I don't understand it.
  27. chemistry

    Chemistry Suspension Examples...]
  28. chemistry

    Chemistry Suspension Examples...
  29. Chemistry

    What is weighted average in chemistry?
  30. chemistry

    i need help with chemistry homework
  31. chemistry

    Abstract 4 chemistry of starch
  32. Chemistry

    What is another name for mole in Chemistry
  33. chemistry

    What does a slash (/) mean in chemistry?
  34. Chemistry

    Road map in chemistry ?
  35. English

    Could you please check this paragraph? It is really urgent. Thank you!! 1)My name is Michele and I was born in Torino on 23 march 1997. When I was three years I went to Rome with my family. 2) Now I have got 14 years old and I go to secondary school . 3)I have got a lot of ...
  36. math URGENT!!!!

    i have a list of 5 different numbers. the sum of 2 of the numbers is 0. the sum of 2 of the numbers is 1. the sum of 2 of the numbers is 2. the sum of 2 of the numbers is 3. the sum of 2 of the numbers is 4.the sum of 2 of the numbers is 5.the sum of 2 of the numbers is 6. the...
  37. Chemistry

    I'm doing a Chemistry project on the element Potassium. I need some sort of color theme to apply to my project because creativity counts. Does anyone have suggestions?
  38. Chemistry

    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!
  39. Chemistry

    Need help with Chemistry, thanks in advance! For the system: 2H2O(g) ↔ 2H2(g) + O2(g) ; at equilibrium 27.0g of H2O, 0.25g of H2 and 16.0g of O2 was found in a 5.0L flask. Calculate the equilibrium constant, Keq.
  40. Chemistry

    My question is I need to change to symbol on sodium ion, \rm Na^+, followed by the formula of a sulfate ion, \rm SO_4{}^{2-} Its my first time in chemistry class.
  41. Biology URGENT!!!!

    I need to know if flagella are on plant or animal cells. I need to know the same for cilia. THIS IS DO TOMMOROW!! Thank you go to google and type in flagella and cilia
  42. 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?
  43. 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...
  44. 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?
  45. 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!
  46. 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!
  47. 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.
  48. Chemistry

    List three advantages and three disadvantages of improvised apparatus in teaching chemistry?
  49. Math Help 2 Questions Urgent!

    1. The Pythagorean Theorem can be used to find distances between two points on a grid. But what about finding distances in three-dimensional space? Consider a rectangular box, which has length l, width w, and height h. What is the distance from one corner to the opposite ...
  50. URGENT! Last calculus question!

    Hey! So, I was wondering if someone could answer this. I am mad studying for my exam and I still have a few questions left that I just don't have time to answer, and the assignment is due tomorrow. Thanks and here is the question: Use calculus and algebraic methods to do a ...

    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 ...
  52. 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...
  53. 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 ...
  54. 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.
  55. 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
  56. 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 =
  57. Physics (URGENT!)

    -vehicle 1: 2,060lbs -vehicle 2: 5,800lbs -both roads are 45mph -The cars were impacted at right angles -roadway was dry, 69 degrees -friction between tire & road: .60=mu -skid marks (PRIOR to impact): v1=20ft, v2=7ft. *you can find the entire problem w/ more info online if ...
  58. science (URGENT!! CORRECT PLEASE))

    (1) The inputs for cellular respiration are: A) Nutrients and carbon dioxide B) Energy and carbon dioxide C) Nutrients and oxygen D) Energy and oxygen ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ My Answer: B ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ (2) The outputs for cellular respiration are A) ...
  59. English

    Could you please check these few sentences? Thank you. It's urgent! 1) Though you are not a qualified Spanish teacher, I'll be happy to have conversation classes with you during my stay in Madrid. 2) I hope we can meet around 5 p.m. every day starting from 5 August. 3) I would...

    The Houston Rockets and San Antonio Spurs will play a "best two out of three" series. Assume that Houston has a probability of 1/3 of winning any game. a. Draw a probability tree showing possible outcomes of the series. Label the branches with appropriate probabilities. b. ...

    The Houston Rockets and San Antonio Spurs will play a "best two out of three" series. Assume that Houston has a probability of 1/3 of winning any game. a. Draw a probability tree showing possible outcomes of the series. Label the branches with appropriate probabilities. b. ...
  62. Physics URGENT!!!

    Gayle runs at a speed of 9.00 m/s and dives on a sled, initially at rest on the top of a frictionless, snow-covered hill, that has a vertical drop of 20.0 m. After she has descended a vertical distance of 4.00 m, her brother, who is initially at rest, hops on her back, and ...
  63. music

    IS THERE ANY MUSIC TEACHERS THAT CAN HELP ME PLEAS??? ITS REALLY URGENT yes do you know what singing points are please? Ok, try this. A point can be defined as the subject of a fugue. In the piece you're analyzing, is there a part that more than one voice sings? For instance, ...
  64. 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.
  65. 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
  66. 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
  67. 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
  68. 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 !!
  69. 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
  70. 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!
  71. Science, very urgent please help

    An experiment is set up to test whether a particular insect prefer a dark or a bright environment. A chamber with a gradient in light intensity from one end (dark) to the other (bright) has been made. The experimental hypothesis is: “There will be a large difference between ...
  72. science very urgent need help

    An experiment is set up to test whether a particular insect prefer a dark or a bright environment. A chamber with a gradient in light intensity from one end (dark) to the other (bright) has been made. The experimental hypothesis is: “There will be a large difference between ...
  73. maths(statistics)

    it is about the system R or R programme. Can anyone help me about the question? Urgent! Let X denote the concentration of calcium carbonate (CaCO3) in milligrams per liter. Following are 20 observations of X: 130.8 129.9 131.5 131.2 129.5 132.7 131.5 127.8 133.7 132.2 134.8 ...
  74. 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
  75. Math [urgent]

    1. The sum of three numbers is 301. The second number is 3 less than twelve times the first number. The third number is 4 more than seven times the number. Find the three numbers. ~~~~~~ 2. Two friends live 15 miles apart. One day they decide to jog and meet each other. Tanya ...
  76. 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
  77. In-class presentation URGENT history

    Hi Look, I'm stuck. I've been trying to get an idea all week. The last thing that I want to do is use a powerpoint as my visual aid. In fact i've removed it from even being considered. At one point I thought about doing a video confrence or asking people-on-the-street what ...
  78. 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.
  79. 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
  80. 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.
  81. 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.

    Please check my answers if it is correct.thanks a lot.GOD BLESS U ALWAYS. •Being independent – not dependent Independent can stay and live alone without anybody’s help. Can be able to survive for whatever things occurred whether bad or good. •Being decisive – not ...
  83. Microeconomics help please (urgent)

    I just want an idea on how to do this, so will only post one example: For each of the following situations, decide whether the bundle Lakshani is thinking about consuming is optimal or not. If it is not optimal, how could Lakshani improve her overall level of utility? That is...
  84. Chemistry

    Name 3 careers where you are required to know PHYSICAL Chemistry, and why those careers require it.
  85. 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...
  88. physics- vry urgent

    A human wave. During sporting events within large, densely packed stadiums, spectators will send a wave (or pulse) around the stadium (Fig. below). As the wave reaches a group of spectators, they stand with a cheer and then sit. At any instant, the width w of the wave is the ...
  89. Science! URGENT

    How might sexual reproduction decrease an organisms chance of survival? A. If the offspring inherits a genetic combination that includes a harmful trait, it could decrease the organisms chance of survival. B. If the offspring inherits the exact sane genetic information as its ...
  90. 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 ...
  91. math urgent

    The state lottery (which has a 6% lottery tax) offers to pay winnings in 25 annual payments or one lump sum, sometimes called a cash-out option. This week’s lottery has a jackpot of $30 million and a cash-out value of $18.2 million. Granted that the odds are highly unlikely ...
  92. Physics Urgent!

    1.You are driving at the speed of 28.7 m/s (64.2138 mph) when suddenly the car in front of you (previously traveling at the same speed) brakes. Considering an average human reaction, you press the brakes 0.427 s later. Assume that the brakes on both cars are fully engaged and ...
  93. Chem Urgent Help ?

    I have a lab dis monday .. plz someone help .. Lab Title is (( Recrystallization of a Solid )) Pre-Lab Questions.... Explain the purpose of the following in this experiment. a) using hot filtration b) not cooling (chilling) the hot filtered solution immediately c) washing the ...
  94. 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 ...
  95. 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.
  96. 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?
  97. 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 ...
  98. Science, HELP!!! URGENT!

    a) If the silty clay loam soil profile is 1 meter deep, how much plant available water (cm) can potentially be held in the upper meter of soil? b) If the silty clay loam profile is 40 inches deep, how many inches of plant available water can potentially be held in the upper 40...
  99. 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 ...
  100. CALCULUS-URGENT- no one will respond!!!

    we know the series from n=0 to infinity of c(sub n)*3^n converges 1. TRUE OR FALSE the series from n=0 to infinity of c(sub n)*2^n must converge 2. TRUE OR FALSE The series from n=0 to infinity of c(sub n)*4^n must converge 3. TRUE OR FALSE the series from n=0 to infinity of c...
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