1. Chemistry

    I've a solution 0.002M of Pb(NO3)2: What is the minimum concentration of iodide ions (I-) necessary to observe the precipitation of PbI2? What mass of KI should be added to observe the precipitation of PbI2 from the 25 mL volume lead nitrate solution?

    asked by sauro on January 19, 2019
  2. Math

    Please observe the solution for the following two problems : (a) 2x + 18 = x + 25 (b) 3x + 5 = 7x - 15 (a) 2x + 18 = x + 25 2x - x = 25 - 18. -------- (1) x = 7 (b) 3x + 5 = 7x - 15 7x - 3x = 15 + 5 ---------- (2) 4x = 20 x = 5 Explain the rules involved

    asked by Learn on March 12, 2019
  3. Chemistry

    If you add Na2CO3 and AgNO3 together in a test tube what exactly would you observe and what would be the equation for the equilibrium system? If you then add HNO3 to the solution what exactly would you observe and what would be the equation for that

    asked by Sylvia on June 20, 2009
  4. Chemistry

    Given one of the following solution: 50.00mL of 0.10M of K2CrO4 answer the following. 1. How do you prepare the solution? 2. What volume (mL) of your solution contains 5.00X10(-4) moles of the solute? 3. What volume of your solution contains 1.00g of the

    asked by Sue on October 17, 2010
  5. chemistry

    I am doing a home lab experiment about acid-base neutralization. I just need a little help to see if I am doing it correctly. I completed the experiment and recorded the data. We were to add 25 ml of vinegar and the 1 ml of cabbage indicator, the add i ml

    asked by Lynn on March 6, 2010
  6. proofread

    Hi, can someone proofread this for me. I'll appreciate it. Thanks in advance. The practicum site I selected is an elementary school. I will be assisting a first grade teacher during the semester. I will be helping her with her students and with other

    asked by Bizzy on February 3, 2008
  7. Chemistry

    A solution is made by dissolving 32g KCIO3 in 100g H20 at 80C. The solution is cooled to 10C. Describe what you would observe as it cooled and state what temperature this first occurs at. What mass of crystals would settle out of the solution?

    asked by Naomi on June 18, 2016
  8. Chemistry

    1.) Explain the similarity between Mg(OH)2 and Zn(OH)2 in particular why would any insoluble hydroxide tend to dissolve in an acidic solution? Are they both bases? 2.) Explain the difference in particular how does Mg^+2 appear to form complex ions with

    asked by Gina on March 20, 2015
  9. analaytical chemistry

    a student mixes equal volume of 1 molar tin chloride and coper sulfate and observe tha no preciptate forms .then the students mxis equal volume of 1molar solution of zinc sulfate and tin floride and observe the formation of precipitate .which compound is

    asked by Gebru on June 13, 2016
  10. Chemistry Acid/bases

    The concentration of H2SO4 in a solution is 3.20 10-6 M. Assume the acid dissociates completely in solution. What is the [H3O+] in the solution? What is the [OH-] in the solution? What is the pH of the solution? What is the pOH of the solution? OK SO I

    asked by Spencer on February 10, 2009
  11. Grammar

    Circle the nouns that can be used with the verbs on the right . Engine-consumption-dependence (reduce) Answer : consumption and dependence Solution-dependence-alternative (find) Answer:solution and dependence Resources-technology-stocks(deplete)

    asked by Maryam on June 6, 2013
  12. Grammar

    Circle the nouns that can be used with the verbs on the right . Engine-consumption-dependence (reduce) Solution-dependence-alternative (find) Resources-technology-stocks(deplete) Quantity-problems-question(solve) Energy-crisis-shortage (face)

    asked by Maryam on June 3, 2013
  13. Math

    For problems 1 and 2, determine how many solutions there are for each triangle. You do not have to solve the triangle. 1. A = 29°, a = 13, c = 27 2. A = 100.1°, a = 20, b = 11 For problems 3-6, solve each triangle using the Law of Sines. If there is no

    asked by Tabitha on January 13, 2011
  14. algebra homework help

    student missed 11 problems on a Chemistry test and received a grade of 65%. If all the problems were of equal value, how many problems were on the test? Round off your answer to the nearest integer. X= # of problems 11= # of missed problems 65% of correct

    asked by jennifer on October 12, 2016
  15. Algebra

    I'm not quite sure about these problems. I know how to do them, but it seems that I get the wrong answer. Maybe I'm supposed to get 'no solution' but I'm not sure. Could someone please help me with them? 5|6-5x|=15x-35 2|3x-7|=10x-8 1/4|4x+7|=8x+16 Ok for

    asked by Maria on September 14, 2006
  16. Chemistry instruments

    what is that tool called the one you put drops of solution in to observe if a ppt is formed?? dish...something??

    asked by Giznelbell on October 19, 2008
  17. Math, Calculus

    help Please... Differential Equations Problems... please give the complete solution, so that i can understand how it is derived... tnx in advance, god Bless... Here are the problems : 1.) y dx + (2x+3y)dy = 0 2.) (2xy + y^(2) ) dx - 2x^(2) dy = 0 ;y = e, x

    asked by Huck on October 19, 2009
  18. algebra

    A student missed 11 problems on a Chemistry test and received a grade of 65%. If all the problems were of equal value, how many problems were on the test? Round off your answer to the nearest integer. X= # of problems 11= 3 of missed problems 65% of

    asked by jennifer on October 12, 2016
  19. Biology

    1aOrder the following steps of microscope use. A. Observe the specimen under low power; resolve with the fine adjustment. B. Raise the stage; observe under scanning power; focus with coarse adjustment; resolve with fine adjustment. C. Observe the specimen

    asked by Anonymous on May 11, 2016
  20. Chemistry

    You are investigating the effect of strong base on the solubility of zinc hydroxide, Zn(OH)2 (s). (Ksp= 3 x 10- 15 for Zn(OH)2 (s)) You prepare 1.0 L solution of 0.10M NaOH and add excess zinc hydroxide, Zn(OH)2 (s). Instead of suppresing the solubility,

    asked by Lily on April 27, 2016
  21. Ions & Atoms-Lab Part 1

    We did a lab on Ions and Atoms. The purpose was basically to identify the properties of an ion and compare them to atoms. These were the Materials -safety goggles -apron -copper(II) chloride (CuCl2) -3 250-ml beakers -water aluminum foil -scissors

    asked by Sara on April 19, 2010
  22. chemistry!

    [blank] mL of 6.0 M H2SO4 are needed to prepare 300 mL of 1.0 M H2SO4 solution. 50 mL x M = mL x M (works for dilution problems but not for all stoichiometry problems.)

    asked by Emi on April 29, 2007
  23. Chemistry please help!

    Please help. I have no idea how to do these 4 homework problems. 1- How many milliliters of 0.140 M HCl are needed to completely neutralize 42.0mL of 0.106 M Ba(OH)2 solution? 2-How many milliliters of 0.123 M H2SO4 are needed to neutralize 0.250 g of NaOH

    asked by Robert on February 22, 2010
  24. 9th Grade Math

    For my hw i have to graph the following equations 1) x - 3y -5 = 0 and 2x = 1 - 3y 2) y - 3x =5 and 3x = 7 + y 3) x = 3y and x +2 = 11 4) y = 2/5x + 1 and x + 2y +11 After done graphing the equations i have to state if there are zero, one, or many

    asked by HELP on March 16, 2009
  25. Math

    help Please... Differential Equations Problems... please give the complete solution, so that i can understand how it is derived... tnx in advance, god Bless... Here are the problems : 1.) y dx + (2x+3y)dy = 0 2.) (2xy + y^(2) ) dx - 2x^(2) dy = 0 ;y = e, x

    asked by Huck on October 18, 2009
  26. Match, Calculus

    help Please... Differential Equations Problems... please give the complete solution, so that i can understand how it is derived... tnx in advance, god Bless... Here are the problems : 1.) y dx + (2x+3y)dy = 0 2.) (2xy + y^(2) ) dx - 2x^(2) dy = 0 ;y = e, x

    asked by Hermione on October 18, 2009
  27. Algebra

    what is two ways to simplify the two problems? problem 1: (-4m^2 n^2)^3 * (2m^3 n)^-1 solution 1: -(32n^5/m^9) Solution 2: ? problem 2: (x^-(1/2) y^3)^-2/ xy^(1/3) * x^2 y^-4 solution 1: 1/x^2y^(7/2) solution 2: ?

    asked by anonymous on August 30, 2018
  28. General Chemistry

    When a solution of nickel (II) chloride is mixed with a stoichiometric amount of colorless sodium hydroxide solution, a green, gelatinous precipitate forms. (a) Write the balanced molecular equation and the net-ionic equation for this reaction. molecular:

    asked by <3 on July 16, 2013
  29. Chemistry

    How do I solve these problems You have 2000. g of aqueous NaOH solution. The percent by mass of the solute is 4.25%. How many grams of NaOH are in the solution? If you have 100.0 mL of a 25.0% aqueous solution of ethanol, what volumes of ethanol and water

    asked by Lucy on October 4, 2014
  30. Algebra 2

    What is the solution for the determinant? |1 7 | |0 -3| How do you find the solution? I'm probably going to feel really stupid because it's probably simple but I'm just having some problems. Okay, a lot.

    asked by Nikki on July 17, 2017
  31. chemistry

    Hey, I am having a real hard time getting the answers to the problems. Any help would be greatly aprreciated! 1. When 11 mL of a solution containing 2.9 M AlBr3 is diluted to 33 mL, a dilute solution is formed. What is the Br- concentration in 25 mL of the

    asked by chelsea on November 7, 2007
  32. math

    Solve the equation for x. For each of the following problems is it possible for x to be equal to: 1? (x+m)/(x−1)=1 If m ≠ -1, there are no solutions\ if m=1, the solution is ? Ii do not now how to find the solution for if m=1 but i got all real

    asked by allie on December 18, 2016
  33. algebra

    I have a few math questions I made them just like my actual problems so that I can go through the steps you have went through to answer my own problems...Again THESE ARE NOT THE REAL PROBLEMS JUST EXAMPLES LIKE MINE WITH DIFFERENT NUMBERS. I don't know how

    asked by Anonymous on June 12, 2013
  34. alg.

    solve and graph 2x-y=4 2x-y=6 would this be x=2+0.5y x=3+0.5y and then graph as that??????? not really sure what i am doing here Put both equations in the form of y=mx +b Then observe that the slope is the same, the lines are parallel, and have no common

    asked by clueless on May 20, 2007
  35. Chemistry

    1.How many grams of KCl is in 225 mL of a 0.452 M solution? 2.What volume in mL of 0.555 M solution contains 85.0g Na2SO4? 3.How many grams of CaCl2 would be dissolved in 2.0L of a 0.10 M solution of CaCl2? Can you please show me how to do these problems?

    asked by Jamie on April 14, 2015
  36. English Language

    I asked this question earlier. I need to write 2 letters of complaint about problems I face at school and problems I face as a student in general but I can't find any problems, could you help me list some problems? Its really really urgent.

    asked by PLEASE HELP ME!!! on February 9, 2009
  37. meaning of a word

    The constitution was an attemt to addrss the problems that existed under the Articles of Confederation. A) list and explain three problems of decentralized power under the articles of confederation. for each problem identify and explain one solution that

    asked by apoorva on August 8, 2006
  38. confirm math answers

    I have 3 problems I need my answers confirmed for. The solution for log subscript 3 1/9 = x is the solution -1/2? Secondl, what is the solution for 9^2x = 3^x+6 does x=2? Lastley is the answer to 3 ^5x+2 = 81 does x= 2/5? Help sincerely appreciated! The

    asked by trish on January 13, 2007
  39. Math

    1. Is the equation true, false, or open? 5x+2=6x+11 a. Open; there is a variable b. True; the expressions are the same for all values of the variables c. False; the expressions are never the same 2. Which equation is an identity? a. 8-(5x+2)=-5x-6 b.

    asked by Shaghayegh on October 12, 2015
  40. ENGLISH

    I HAVE BEEN ASKED TO WRITE AN ARTICLE ABOUT FEMALE MOSQUITO, PROBLEMS CAUSED BY FEMALE MOSQUITO, SOLUTION TO THE PROBLEMS AND CONCLUSION.

    asked by priya on June 21, 2009
  41. Probability

    A fair coin is tossed repeatedly and independently. We want to determine the expected number of tosses until we first observe Tails immediately preceded by Heads. To do so, we define a Markov chain with four states, {S,H,T,HT}, where S is a starting state,

    asked by qwerty on May 19, 2015
  42. Physics

    As an astronaut, you observe a small planet to be spherical. After landing on the planet, you set off, walking always straight ahead, and find yourself returning to your spacecraft from the opposite side after completing a lap of 24.0 km (assume this to be

    asked by Anonymous on February 11, 2014
  43. statistics

    in a classic study of problem solving, katona demonstrated that people whoa re required to figure out a problem on their own will learn more than people who are given the solution. One group of participants is presented with a series of problems that hey

    asked by Lezlie on June 11, 2008
  44. Probalility

    A fair coin is tossed repeatedly and independently. We want to determine the expected number of tosses until we first observe Tails immediately preceded by Heads. To do so, we define a Markov chain with four states, {S,H,T,HT}, where S is a starting state,

    asked by Volcom on May 15, 2015
  45. sat essay

    Is it necessary for us to find new solutions to problems? Many people may argue that we don¡¯t need to since we are already able to solve the problems. As far as I am concerned, we should always try to find new solutions to problems. New solutions enable

    asked by Mercedes on December 2, 2009
  46. ap chemistry

    please explain titration problems. I'm a total noob at this and am trying to answer some prelab questions. Examples: 1. How many mL of a 0.800 M NaOH solution is needed to just neutralize 40 mL of a 0.600 M HCl solution? 2. You wish to determine the

    asked by chris on October 2, 2008
  47. Chemistry

    I have a test on monday and I NEED to ace it in order to raise my grade > . < ldsfkjaslkf right now, acids and bases are killing me can somebody help me with these problems? A buffer solution is prepared by mixing the weak base ammonia (Kb=1.77x10^-5) with

    asked by Kimberlee on May 15, 2010
  48. physics

    As an astronaut, you observe a small planet to be spherical. After landing on thte planet you set off, walking always straight ahead, and find yourself returning to your spacecraft from the opposite side after completing a lap of 26.5 km. You hold a hammer

    asked by sydwell on May 8, 2014
  49. Chemistry

    What is the concentration of HCl when 25.0 mL of HCl completely reacts with 10.0 mL of 0.1M solution of NH4OH (subscript 4)? Solution steps would be helpful so I can solve other similar problems.

    asked by Cody on November 22, 2010
  50. math

    Here are a few problems I need solving Make sure to show a check for the solution and write the solution in set notation like {x|x>5}: Solve for y -7y-14>42 Solve for x -2(4x+5) < 2x-20

    asked by Anonymous on September 22, 2010
  51. SCIENCE AGAIN

    My book does not have this question in it either. I tried various web sites. Maybe someone could help. Thank you "__________ is the solution to pollution" is an old axiom responsible for much of our problems in estuarine contamination. I am guessing that

    asked by Meg on May 17, 2007
  52. math

    there's a question that I don't understand and the direction says that 'solve problems as combination integer problems.remember to rewrite all double sign problems as combination problems before solving' and here's a question 50- -61+ - 170 =

    asked by allie on January 22, 2008
  53. Chemistry 1

    We are working on molarity of a solution in my class, and I am a little stumped on how to set the problems up. Here is one question from my homework. How many grams of NaCl are needed to make 575mL of 1.5 M NaCl solution? Thank you in advance :)

    asked by Emily on January 3, 2013
  54. math

    A 25% vinegar solution is combined with triple the amount of a 45% vinegar solution and a 5% vinegar solution resulting in 20 milliliters of a 30% vinegar solution. Write an equation that models this situation and explain what each part represents in the

    asked by Bob on November 26, 2018
  55. chemistry

    need help with these problems: The concentration of glucose in blood is usually about 0.10% (w/v). If 7.0 L of blood are in an average man, how many grams of glucose are in his blood? To obtain the solute for 118 g of a 19.2% (w/w) solution of sugar we

    asked by ellen on July 20, 2010
  56. math

    Can someone check over these problems for me? 1. The width of a rectangle is fixed at 28 cm. What lengths will make the perimeter greater than 70 cm? A: the length must be greater than 7 cm. 2. 7x=-63 A: x=-9 3. Is (-8.-9)a solution of 2x+4y=12 A: No 4.

    asked by deedra on January 8, 2009
  57. Chemistry (urgent)

    Hi, I have a few chemistry problems that I'm having trouble solving. I put my attempted solutions after the problems in *'s. There was one problem I had no idea how to solve. What concentration of silver chromate (Ksp = 9.0 x 10-12) will dissolve to make a

    asked by Maggie on April 12, 2010
  58. math

    kenneth has 22 math problems to do for homeworks he has 12 problems done. How many more problems does he have left? If he completes 1 problem every minute, how many more minutes does he have to work?

    asked by wonderer on October 5, 2011
  59. Math

    Kenneth has 22 math problems to do for homework. He has 12 problems done.How many more problems does he left?if he completes 1 problem every minute,how many more minutes does he have to work?

    asked by Tanny on August 27, 2013
  60. Language Arts

    I need help thinking of 4 small problems in our world. I have to have 4 problems, solutions attempted to those problems and a problem solving invention. I really need help please and thank you.

    asked by Please help on February 7, 2019
  61. Chemistry

    I have two substances potassium sulfate and potassium carbonate. They are unlabelled and I need to know which one is which. If I add HCl to each substance ie K2SO4(s) + 2HCl(aq)-->2KCl(aq) + H2SO4(aq) K2CO3(s) + 2HCl(aq)--> 2KCl(aq) + H2O(l) + CO2(g) What

    asked by Fiona on April 24, 2007
  62. Chemistry - Solubility Product

    What did you observe after the addition of dilute HCl to the saturated lead chloride solution? Explain observations using relevant chemical reaction. I observed that a white precipitate was formed. Not sure how to explain why it formed

    asked by PleaseHelp on March 29, 2014
  63. Chemistry

    What did you observe after the addition of dilute HCl to the saturated lead chloride solution? Explain observations using relevant chemical reaction. I observed that a white precipitate was formed. Not sure how to explain why it formed

    asked by PleaseHelp on March 29, 2014
  64. math

    So I've been having trouble solving some problems. Mainly problems that look like this 5-(t+3)=-1+2(t-3) what causes problems is the 5- part. I asked my teacher for help, and he gave me a hint, which is to distribute a -1 like 5+(-1)(t)+(-1)(3) But I still

    asked by katherine on October 7, 2010
  65. science

    1. Which of the following is TRUE regarding this situation: Solution A has a pH of 7.38, and Solution B has a pH of 7.42? a.Solution B is more acidic than Solution A b.The pH of Solution A falls within the homeostatic pH range for extracellular body

    asked by a on January 28, 2013
  66. Chemistry I - University

    Suppose 5.87 g of barium acetate is dissolved in 300. mL of a 71.0 m M aqueous solution of sodium chromate. calculate the final molarity of barium cation in the solution. You can assume the volume of the solution doesn't change when the barium acetate is

    asked by Jessica on September 27, 2015
  67. psychology

    A production executive,using deductive reasoning as an approach to solving problems,concludes that there is only one correct solution to every problem.The flaw in his reasoning is that: a)it allows his managers to find their own answers b) clear solutions

    asked by vedrana on October 16, 2009
  68. Chemistry

    Hi,can I have your help? I'm just trying to solve a few Dilution Solution problems. I'm stuck on these two,and I wish you could help. Here's one: A 500 mL bottle of concentrated acetic acid is diluted to make a 5.0% solution. Find the volume of diluted

    asked by Cliff on December 8, 2010
  69. MATH

    cos(x)=2 and sin(x)=5 Thanks for your previous answers mathmate. No. It's not a typo. I was wondering if someone could explain to me when in real life would I need to solve such problems, or similar, besides answering problems from a textbook. When ever I

    asked by George on July 15, 2011
  70. Science

    Why do scientists study images made with parts of the electromagnetic spectrum other than visible light? A)These images are the only way to observe galaxies beyond our own. B)These images reveal information that visible light does not show. C)These images

    asked by Cam on April 4, 2016
  71. world history

    Re: Industrial Revolution Apart from external problems including urban crowding, insanitation, pollution, and social and order problems, what may have also been (2) problems created by industrialization/urbanization during this time?

    asked by hellga on February 9, 2008
  72. Biology

    The problems of survival of animals on land are very different from those of survivial of animals in an aquatic environment. Describe four problems associated with animal survival in terrestrial environments but not in aquatic environments. For each

    asked by Neil on March 18, 2012
  73. HCS/335

    Are laws and regulations the problem or the solution in addressing ethical problems? Explain. What would be an alternative? I got this from ms.sue and i need to strech it into 300 words? can anyone help me? Laws and regulations help in guiding human

    asked by Tina.....HELP PLZ on February 2, 2011
  74. comparing fractions

    A third grade class was given a multiplication quiz. The quiz had 10 problems. Any correctly answered 6 problems, Bobby answered 7 problems correctly, Tom answered 9 problems correctly, and Sue only answered 2 problems correctly. A. What fraction of the

    asked by Emma on December 4, 2016
  75. ap chem

    A certain volume of a .50 M solution contains 4.5g of a certain salt. What mass of the salt is present in the same volume of a 2.5 M solution? Indicate the concentration of each ion/molecule: A mixture of 50.0 mL of .2M KClO3 and 25.0 mL of a .20M Na2SO4.

    asked by lily on September 13, 2007
  76. Chemisty

    Consider a 1.50 L aqueous solution of 3.75 M NH3, where 17.5 g of NH4Cl are dissolved. To this solution, 5.00 g of MgCl2 are added. a. What is [OH-] before MgCl2 is added? b. Will a precipitate form? c. What is [Mg2+] after equilibrium is established? I

    asked by Olivia on November 14, 2013
  77. math

    Solution for: A man 1.7m tall observe that the angle of elevation of a top of a tower to be 28°.He moves 50m away from the angle of elevation to be 35°.How far above the ground is the tip of the tower to three significant figures.

    asked by Gyamfi on February 10, 2016
  78. chemistry

    Observe the diagram of the electrolytic cell (A aqueous solution of molten salt with a power supply). The molten salt is lithium flouride. Write the half reaction occuring at the cathode, following the usual style guide and making sure to balance

    asked by johnathan on September 30, 2015
  79. chemistry

    Several reactions are carried out using AgBr, a cream-colored silver salt for which the value of the solubility product constant, Ksp, is 5.0 x 10-13 at 298 K. a) Calculate the value of [Ag+] in 50.0 mL of a saturated solution of AgBr at 298 K. b) A 50.0

    asked by jack on March 13, 2015
  80. Math

    I am having problems understanding how to solve problems like the following: a2 + b2 = c2 Please help me where I can understand solving problems such as the one above.

    asked by Jasmine on March 30, 2009
  81. math

    matthew got 36 problems right out of a total of 40 problems on a test. What percent of the problems did he get right?

    asked by Michelle on November 14, 2010
  82. English

    1. Do first things first. 2. Do the first things first. (Which one is right?) 3. What kinds of health problems does the people in the pictures have? Look at the person in Picture One. He is holding a measuring tape. Doesn't he look heavy? He needs to be on

    asked by John on September 1, 2009
  83. Chemistry

    Hi, I have a few chemistry problems that I'm having trouble solving. I put my attempted solutions after the problems in *'s. There was one problem I had no idea how to solve. What concentration of silver chromate (Ksp = 9.0 x 10-12) will dissolve to make a

    asked by Maggie on April 12, 2010
  84. Chemistry

    My final exam is coming up so I am doing study guides to help me practice. I would really appreciate any help that is given. 1. The hydronium ion concentration for a solution is determined to be 4.5 x 10^-7 M. What is the concentration of the hydroxide

    asked by Studying on November 25, 2012
  85. science

    Astronomers know that the best time to observe stars is when there is a New Moon. The New Moon allows the astronomers to observe the stars when the Moon is 0% lit. How many days will the astronomers have to wait if the Moon phase is currently the one

    asked by huhuuh on October 11, 2018
  86. Literature

    'When you finish with this section, you will write an observational essay. This essay will be a description of a person, place, or thing you can observe. You'll write using sensory details and perhaps a bit of narrative. Some key elements will be sharp,

    asked by mysterychicken on December 18, 2009
  87. Chemistry help

    1. Find the pH when there are 0.034 moles of h+ in a liter of solution 2. Find the pH when there are 1.6x10^-7 moles of h+ in 500 ml of solution Please help me on these only problems im struggling with, thank you!

    asked by Heather on May 4, 2015
  88. Math/ Algebra

    Ms. Sue please I need help with these two problems! Tell whether the given number is a solution of each question 5b+1=16; -3 14=1/3x+5;27

    asked by Algebra Please Help Ms. Sue! on October 10, 2016
  89. Science

    Hello, hope u guys are having a good day! I need some help on this science! Thank you! Water cycle. Which of these stages of the water cycle were you able to observe in your model? What is the energy source in your model and what does it represent? Did you

    asked by Skylar on May 13, 2019
  90. Science-Physics

    The metre was originally defined as a fraction of the distance from the North Pole to the equator. What problems would this definition of the metre create for people? Would some problems be the long calculation? I can't really think of other problems.

    asked by Anonymous on November 6, 2010
  91. Statistics-Probability

    An instructor will choose 3 problems from a set of 7 containing 3 hard and 4 easy problems. If the selection is made at random, what is the probability that only the hard problems are chosen?

    asked by Steven on February 5, 2013
  92. Chemistry

    Could someone help me with these problems; A)If 5.97mL of a solution of NaCl contains 2.54g of sodium ion, what is the molarity of the sodium chloride solution? -I know M=#moles solute/L but when I do this I get 7.28*10^-3 which is wrong, the answer should

    asked by Adam on January 28, 2011
  93. algebra

    janice noticed that the number of problems she did for homework (x) formed a linear relationship with her quiz score (y). When she did 3 problems she earned a 25% and when she did 8 problems she earned a 60%. Write an equation to represent this situation.

    asked by andrew on January 20, 2010
  94. Math

    1. what is the solution o 204 - (-36)? A 240** B - 240 C 168 D -168 2. what is the solution of 87 + (-396)? A 183 B -183 ** C 9 D -9 3. Evaluate: -12 x 3 =? A 36 B -36** C 4 D -4 4. Evaluate: -20 ÷ -10 =? A 200 B -200 C 2 **8 D -2 5. Select all the

    asked by Caroline on September 12, 2016
  95. college chemistry - molarity question

    My textbook doesn't show me how to do problems like the following, and I'm having a hard time finding similar problems online. Most of the molarity problems I'm finding involve mixing a substance with water, but these involve mixing moles of substances

    asked by lholmq on April 29, 2009
  96. math

    in the addition problems below each leter represents the same digit in both problems. Replace each letter with a different digi, 1-9, so that both addition problems are true.(there are two possible answers.) A B C A D G +D E F +B E H ------ ------ G H I C

    asked by kenzie on August 23, 2007
  97. chemistry

    I have many questions. I have a test tuesday and need to get these problems done and understand them today because i am currently studying. I am in college and my professor has not emailed me back regarding solutions for the review problems she posted. Is

    asked by Sarah (C) on April 23, 2011
  98. Algebra

    Here is the problem: A two-digit number is eight times the sum of its digits.When the number is added to the number obtained by reversing the digits,the sum is 99. Find the original number. Please explain hot to solve it and it would help a lot to if you

    asked by Anonymous on May 31, 2010
  99. Algebra

    Here is the problem: A two-digit number is eight times the sum of its digits.When the number is added to the number obtained by reversing the digits,the sum is 99. Find the original number. Please explain hot to solve it and it would help a lot to if you

    asked by Please help on May 31, 2010
  100. Chemistry

    A 1N solution of NaOH is diluted 4/20 then rediluted 1:50. What is the final normality? How many grams of NaOH are present in 100ml of the final solution? I sort of understand the basic concept, but I don't really know how to do normality problems.

    asked by Jennie on May 20, 2014