1. chemistry

    Calculate the molar enthalpy change for this reaction: HCl(aq 1.00M) + NaOH -> NaCl(aq,.500M)+ H2O Initial temp: 22.15 degrees Celsius Extrapolated temp: 25.87 degrees Celsius DT: 3.72 degrees Celsius Notes: Calculate the enthalpy change for this reaction.
  2. Chemistry

    Identify the following chemical equations by type. 1. If an electric discharge produces 500 cm3 of ozone (O3), how many cm3 of oxygen (O2) are required? 3O2(g) ---> 2O3(g) 2. When 2.75 dm3 of O2 react with an excess of glucose (C6H12O2), according to the
  3. chemistry

    Consider the reaction shown: 452 kcal + 4 PCl5 (s) ¨ P4 (s) + 10 Cl2(g) This reaction is ________ because the sign of ƒ¢H is ________. A) exothermic; neither positive nor negative B) endothermic; positive C) endothermic; negative D) exothermic;
  4. Chem

    Consider the reaction shown: 452 kcal + 4 PCl5 (s) ¨ P4 (s) + 10 Cl2(g) This reaction is ________ because the sign of ƒ¢H is ________. A) exothermic; neither positive nor negative B) endothermic; positive C) endothermic; negative D) exothermic;
  5. Chemistry

    4. Use the information above to write net ionic equations for the two reactions that you have observed. 5. For each reaction, write the two half-reactions that make it up and calculate the overall reaction potential by adding the two half-reactions. Each
  6. Chemistry

    Marble is almost pure CaCO3. Acid rain has a devastating effect on marble statuary left outdoors. Assume that the reaction which occurs as: CaCO3(s)+ H+(aq)->Ca2+(aq) + HCO3(aq) Neglecting all other competing, equilibria, Calculate: 1. K for the reaction
  7. math

    2. What answer represents this number in scientific notation? 0.00000916 a. 916 x 10^-8 b. 9.16 x 10^-6 c. 916 x 10^8 d. 9.16 x 10^6 3. What is this number in standard form? 6.8 x 10^-4 a. 5,750,000,000 b. 575,000,000,000 c. 0.00000000575 d. 0.575000000000
  8. math

    2. What answer represents this number in scientific notation? 0.00000916 a. 916 x 10^-8 b. 9.16 x 10^-6 c. 916 x 10^8 d. 9.16 x 10^6 3. What is this number in standard form? 6.8 x 10^-4 a. 5,750,000,000 b. 575,000,000,000 c. 0.00000000575 d. 0.575000000000
  9. Language Arts

    The arrow and the song poem 1 i shot an arrow into the air, 2 it fell to earth, i know not where; 3 for, so swiftly it flew, the sight 4 could not follow in its flight Part A Which form best describes the poem this excerpt is from A. lyric poem B. concrete
  10. college chem

    You are instructed to create 400. mL of a 0.40 M phosphate buffer with a pH of 6.9. You have phosphoric acid and the sodium salts NaH2PO4, Na2HPO4, and Na3PO4 available. (Enter all numerical answers to three significant figures.) H3PO4(s) + H2O(l)
  11. Chemistry

    According to the following reaction, how many moles of hydrogen iodide will be formed upon the complete reaction of 30.0 grams of hydrogen gas with excess iodine? hydrogen (g) + iodine (s) hydrogen iodide (g) moles hydrogen iodide
  12. algebra

    Write the equation of the line that passes through point (5, 4) with a slope of 0. would this be x=5 then? no x=5 is the equation of the vertical line passing through (5,4) Any horizontal line, (slope=0), has an equation of the form y = b notice that this
  13. chemistry

    N2(g) + 3 F2(g) → 2 NF3(g) ΔH° = –264 kJ/mol ΔS° = –278 J/(mol∙K) a. Using the information provided above (only), calculate the maximum amount of non-PΔV work that can be accomplished through this reaction at a temperature of 500°C. b.
  14. Chemistry

    Acetic acid is a polar molecule and can form hydrogen bonds with water molecules. Therefore, it has high solubility in water. Yet acetic acid is also soluble in benzene (C6H6), a nonpolar solvent that lacks the ability to form hydrogen bonds. A solution of
  15. history

    Which best describes a democracy? form of government in which political power is held by a single ruler form of government in which political power is held by the people government based on appointing officials according to merit and academic
  16. Chem

    Consider the following reaction: 6A + 2B 5C + 4D Determine the following rates at a time when the rate of consumption of B is 2.5E-05 M/s. a) rate of consumption of A M/s b) rate of formation of C M/s c) rate of formation of D M/s d) rate of reaction M/s
  17. Spanish

    How would you conjugate the verb "decir" which means to say, to the "yo" form? Would it be digo? Or dico? Please help! Thank you for using the Jiskha Homework Help Forum. The verb "decir" is irregular in the "yo" form of the Present Indicative Tense: digo,
  18. Chemistry

    Silicon Carbide, SiC, is prepared by heating silicon dioxide in the presence of graphite. Carbon dioxide is the by-product of the reaction. How many grams of silicon carbide can be formed from the reaction of 50.0 grams fo graphite with 50.0 grams of
  19. Chemistry

    According to the following reaction, how many moles of water will be formed upon the complete reaction of 22.6 grams of hydrochloric acid with excess iron(III) oxide? hydrochloric acid (aq) + iron(III) oxide (s)--> water (l) + iron(III) chloride (aq)
  20. Chemistry

    Please check to see if I got these right and specifically for #2, I am not sure if I have this balanced correctly. Write the complete balanced equations for the following: 1) Potassium metal reacts with oxygen gas to form solid potassium oxide. My answer:
  21. Chemistry

    1) Write a balanced chemical equation for the reaction between Cu(NO3)2 * 3 H2O and NaOH. Underline the formula for the precipitate produced by this reaction. (The water of hydration in Cu(NO3)2 * 3 H2O appears as liquid water on the right side of the
  22. Chemistry

    Acid-Base Titrations These are fill in the blank and I really am not sure what the answers are 1. Indicators change color over a range that is called its ---? 2. The common indicator ---? is very useful in studying neutralizations that involve strong acids
  23. Calculus

    The police department must determine a safe speed limit on a bridge so that the flow rate of cars is at a maximum per unit time. The greater the speed limit, the farther apart the cars must be expected to be in order to allow for a safe stopping distance.
  24. Chemistry(Thank you for helping)

    1) Given this data in a study on how the rate of a reaction was affected by the concentration of the reactants Initial Rate, RUN # (A), M (B), M (C), M mol L-1 s-1 1 0.200 0.100 0.600 5.00 2 0.200 0.400 0.400 80.0 3 0.600 0.100 0.200 15.0 4 0.200 0.100
  25. science

    why does limestone form often in dry climates but rarely in wet climates? http://en.wikipedia.org/wiki/Limestone Why does limestone often form cliffs in dry climates rather than wet climates. i don't know
  26. Biomechanics

    A person with a body mass of 65 kg was running over level ground with a strong tailwind, while wearing a 10 kg weighted vest. The tailwind applied a force of 125 N to the runner’s body in the horizontal direction. Early in the stance phase, the runner
  27. Science

    (1)A geologist was studying rocks in a mountain range. She found a layer of sedimentary rock that had formed in the ocean. Hypothesize how this could happen. My (Answer) Sedimentary rocks forms when sediments have been pressed or cemented together , or
  28. CHEMISTRY

    Hello, I am having trouble balancing this redox reaction WITHOUT using the half-reaction method. I believe this is because not all of the elements are in (aq). BrO3-(aq) + N2H4(g) --> Br-(aq) + N2(g) Br is reduced by a factor of 6. N is oxidized by a
  29. chemistry

    My chem book gives me the following Hess' Law example: Mg + 2HCl --> H2 MgCl2 Delta H1 MgO +2HCl --> H2O +MgCl2 Delta H2 H2 + 1/2 O2 --> H2O Delta H3=-68.3kcal The desired reaction is the formation reaction of MgO as follows: MgS +1/2 O2 --> MgO Delta H
  30. O-Chem

    A student wished to prepare ethylene gas by dehydration of ethanol at 140 C using sulfuric acid as the dehydrating agent. A low-boiling liquid was obtained instead of ethylene. What was the liquid, and how might the reaction conditions be changed to give
  31. Physics

    To stop a car, you require first a certain reaction time to begin braking. Then the car slows under the constant braking deceleration. Suppose that the total distance moved by your car during these two phases is 56.7 m when its initial speed is 80.0 km/h,
  32. math,correction

    Can someone correct these for me please... Multiply. (x+2)(x-2) My answer..x^2-4 Write in descending-exponent form, and give the degree 4x^5+x^8-7 My answer: In descending-exponent form would be: x^8+4x^5-7, The degree is 8 Multiply. 3xy^2(5xy-4x+6y) My
  33. Chemistry

    In a particular redox reaction, BrO– is oxidized to BrO3– and Cu2 is reduced to Cu . Complete and balance the equation for this reaction in acidic solution. Two half reactions: 1.) Cu^2+ --> Cu^+ 2.) BrO^- --> BrO3^- Balanced: 1.) Cu^2+ +e^- --> Cu^+
  34. Chemistry

    A student mixes 5.0 mL of 0.00200 M Fe(NO3)3 with 5.0 mL 0.00200 KSCN. She finds that the concentration of FeSCN2+ in the equilibrium mixture is 0.000125 M. Follow these steps to determine the corresponding experimental value of Kc for the reaction of Fe3+
  35. Chemistry

    Given the reactant side of the total ionic equation for the neutralization reaction of ammonium hydroxide (NH4OH) with hydrochloric acid (HCl), write the total ionic equation (also known as the complete ionic equation) by entering both the reactant and the
  36. Physics

    For a L-C-R circuit Vin = v0*expjwt. Vout is taken across R a) Calculate the impedance of the circuit measured from the input side. Express the impedance in polar form. b) Calculate the gain=Vout/Vin and express the ratio in polar form. c) Sketch the
  37. chemistry

    A middle-aged man has been diagnosed as being at high-risk of developing Coronary Artery Disease. * State the chemical composition of the sterol that is present in high levels in most people who belong to the high-risk group. * Distinguish between the
  38. Chemistry

    A middle-aged man has been diagnosed as being at high-risk of developing Coronary Artery Disease. • State the chemical composition of the sterol that is present in high levels in most people who belong to the high-risk group. • Distinguish between the
  39. Chemistry

    A middle-aged man has been diagnosed as being at high-risk of developing Coronary Artery Disease. •State the chemical composition of the sterol that is present in high levels in most people who belong to the high-risk group. •Distinguish between the
  40. Chem

    middle-aged man has been diagnosed as being at high-risk of developing Coronary Artery Disease. •State the chemical composition of the sterol that is present in high levels in most people who belong to the high-risk group. •Distinguish between the
  41. SS

    How is unity and division a theme in Canadian history? How did distinct English and French populations form in Canada? What is the relationship between natural resources and European settlement? How is conflict and compromise a theme in Canadian history?
  42. chemistry

    According to the following reaction, how many grams of sulfur trioxide will be formed upon the complete reaction of 21.2 grams of oxygen gas with excess sulfur dioxide? sulfur dioxide (g) + oxygen (g) sulfur trioxide (g)
  43. Chemistry

    According to the following reaction, how many grams of nitrogen gas will be formed upon the complete reaction of 22.2 grams of hydrogen gas with excess nitrogen monoxide? nitrogen monoxide (g) + hydrogen (g) nitrogen (g) + water (l)
  44. Chemistry

    1.What hydrocarbons generally will undergo an immediate reaction with Br? 2.What hydrocarbons generally will undergo an immediate reaction with KMnO4 Choices for both are Alcohols,Alkanes, Alkenes, Aromatics I think for 1. is at least Alkenes and maybe
  45. Chemistry

    1.What hydrocarbons generally will undergo an immediate reaction with Br? 2.What hydrocarbons generally will undergo an immediate reaction with KMnO4 Choices for both are Alcohols,Alkanes, Alkenes, Aromatics I think for 1. is at least Alkenes and maybe
  46. Algebra, PLEASE HELP ME!!!

    I am so lost, can anyone help me? I don't even understand what the teacher wants out of me with this problem. Suppose that a market research company finds that at a price of p = $20, they would sell x = 42 tiles each month. If they lower the price to p =
  47. math

    a. Suppose a market research company finds that at a price of p = $30, they would sell x = 32 baskets each month. If they lower the price to p = $10, then more people would purchase the baskets, and they can expect to sell x = 52 baskets in a month’s
  48. chemistry

    N2 + O2 --> 2 NO change in heat (delta H)= 43.2 kcal based on the reaction, which statement is true? a) 43.2 kcal are consumed when 1.00g of O2 reacts b) 43.2 kcal are consumed when 1.00g of N2 reacts c) 43.2 kcal are consumed when 1.00g of NO is produced
  49. precalc

    1. Find (-1+i)^1/3 2. Express 2(cos5pi/3 + isin5pi/3) in regular form. would this be correct: 1-√3i? 3. Find (2+4i)^3 in regular form. 4. Express 5(cos5pi/6 + isin5pi/6) in regular form. would this be correct?: -5√3/2 +5/2i?
  50. CHEM-last part prob.

    Aluminum reacts with chlorine gas to form aluminum chloride via the following reaction: 2Al(s) + 3Cl2(g) -> 2AlCl3(s) You are given 19.0g of aluminum and 24.0g of chlorine gas. a)If you had excess chlorine, how many moles of of aluminum chloride could be
  51. FRENCH! HELP!

    so i have this french test tomorrow on imparitive, and subjonctif. i have had a lot of trouble remembering them, and telling them apart. can anyone help!? that would be fantastic! thank you so much! its urgent! Imperative (note spelling) means giving a
  52. Chemistry(please help)

    I have to calculate the concentration of I2 produced (# of moles of I2 produced / L) based on the stoichiometric ratio in the following equation. 2S2O3^2- + I2 -> 2I^- + S4O6^2- So I got 6.6e-3 L*min for the amount of I2 produced. Now I have to calculate
  53. English

    I urgently need you to check these sentences. Thank you. 1) As our students we'll probably have to learn science in English in their last year of high school, we would rather they used English as the lingua franca for their Comenius project. 2) I think
  54. history

    C/C between american slavery and encomienda system. The encomienda system was a form of land ownership set up after 1492 to divide both the lands and peoples of the New World into workable pieces that were run by Spanish settlers. This system was abused.
  55. Chem

    First off, thanks for the help on the other problems... For the reaction, A(g) + 2 B(g) 2 C(g), Kc = 1 x 10-10 at 25°C. Which of the following statements is true? 1. Delta n = +1 2. The concentration of the products is greater than the concentration of
  56. Chemistry

    Hi I have two questions and I was hoping someone could help me with them. 1. Classify the following compounds as ionic or covalent a. MgCl2 b. Na2S c. H2O d. H2S 2. Which compound in each pair exhibits the stronger intermolecular hydrogen bonding? a. H2S
  57. Spanish!!!!!! Can Anyone Help Please!!

    Which one would be correct: La semana pasada ellos me DIERON dinero. Or La semana pasada ellos me DI dinero. There's me so i don't know if it should be dar in the yo form or the they form for ellos.
  58. English

    1. He spent much money on clothes. 2. He spent too much money in buying books. 3. He spends lots of money traveling to many countries. 4. He spends plenty of time watching TV. 5. He spent a lot of time in buying items in the department store. Are all
  59. AP CHEMISTRY

    The following acid-base indicators are available to follow the titration. Which of them would be most appropriate for signaling the endpoint of the titration? EXPLAIN ------- COLOR CHANGE ------ INDICATOR Acid form Base Form pH Transition Interval
  60. math

    A model rocket is shot straight up into the air. The table shows its height, h(t), at time t. Graph the table below and determine a function, in standard form, that estimates the height of the rocket at any given time. Time(s) Height (m) 0 0.0 1 25.1 2
  61. AP CHEMISTRY

    The following acid-base indicators are available to follow the titration. Which of them would be most appropriate for signaling the endpoint of the titration? EXPLAIN ------- COLOR CHANGE ------ INDICATOR Acid form Base Form pH Transition Interval
  62. chemistry

    Which factors below affect the rate of a chemical reaction? -Collision frequency -Number of collisions having the least activation energy -Intermolecular orientation -Being Exothermic or Endothermic Also, what formula would I use for this problem: "What is
  63. Math(check)

    1)Find the range of the relation [(-1,4)},(2,5),(3,5)}.Then determine whether the relation is a funtion. 4,5,5 is the range 4,5 is a function 2)Find f(-1),if f(x)= x^2-6x/x+2 (-1)^2-6(-1)/-1+2 1+6/-1+2 7/1 =7 3)Find f(a),if f(t)= 2t^2-t-2. 2(a)^2-a-2
  64. physics

    Under what circumstances, if any, will a converging lens form an inverted image of a real object? Under what circumstances, by itself, will a diverging lens form an erect image of a real object?
  65. Chemistry

    Palladium-107 undergoes â decay (t1/2 = 6.5 x 105 yr) to form silver-107. How long will it take for 0.150 mol of silver-107 to form from 1.25 mol of palladium-107? help please...thank you :)
  66. chemsitry

    A sample consisting of 0.025 mol of a solid compound is placed inside a metal cylinder. The cylinder was immersed in a water bath consisting of 10.00 kg of water at an original temperature of 25.00 °C. When the compound decomposes, the temperature of the
  67. Chemistry

    Difference between hydration and hydrogenation reactions? I have searched everywhere in my book and all I can come up with is: Hydorgenation is when atoms of hydrogen H2 are added to the carbons in a double or triple bond of alkenes or alkynes to form what
  68. chemistry

    A 40-year old man, at a prominent legal firm experiences abdominal pain post lunch. He takes several trips to the restroom, but continues to experience pain and cramps. He decides to go to the doctor and admits he consumed 2 bottles of beer @ lunch. The
  69. Math

    1.Divide.Write your answer in simplest form. (1 point) 2/3 divided by 1/4 a.2 1/2 b.2 2/3 c.2 3/8 d.2 2.Find the product. (1 point) 1/2*3/7 a.4/14 b.3/14 c.7/6 d.2/7 3.Divide.Write the quotient in simplest form. (1 point) 3/5 divided by 2/10 a.6/10 b.3/5
  70. Pre-calculus HELP PLASE !

    1.Write the rectangular equation in polar form. (x – 4)2 + y2 = 16 2.Write the equation –2x + 6y = 7 in polar form. 3.Graph the polar equation 2 = r cos(theta – 20°). 4. Write the polar equation in rectangular form. r = –12 cos
  71. Math HELP PLEASE! QUICK!

    1.Write the rectangular equation in polar form. (x – 4)2 + y2 = 16 2.Write the equation –2x + 6y = 7 in polar form. 3.Graph the polar equation 2 = r cos(theta – 20°). 4. Write the polar equation in rectangular form. r = –12 cos
  72. Chemistry

    I have a few questions, if anyone can help me at all it would be amazing. i need this done by TOMORROW (03/03/2008) 1. Cyanogen has been observed in the atmopshere of Titan, Saturn's largest Moon, and in the gases of the interstellular nebulas. On Earth,
  73. Chem

    I have a few questions, if anyone can help me at all it would be amazing. i need this done by TOMORROW (03/03/2008) 1. Cyanogen has been observed in the atmopshere of Titan, Saturn's largest Moon, and in the gases of the interstellular nebulas. On Earth,
  74. Chemistry

    If 26.4 grams of nitrogen and 30.1 grams of oxygen combine to form nitrogen monoxide, how many grams of nitrogen monoxide must form? I am confused on how to do the math.
  75. math

    The graph of an equation in the form y=mx + b is a straight line. Can the equation of every straight line be written in the form y=mx + b (Hint: What is the equation of a vertical line?)
  76. Chemistry

    For the following reaction, 9.91 grams of sulfur are allowed to react with 20.8 grams of carbon monoxide . sulfur(s) + carbon monoxide(g) sulfur dioxide(g) + carbon(s) is the maximum amount of sulfur dioxide that can be formed? What is the FORMULA for the
  77. Chmistry

    For the following reaction, 4.35 grams of hydrogen gas are allowed to react with with 10.3 grams of ethylene (C2H4). hydrogen (g) + ethylene (C2H4) (g) ethane (C2H6) (g) What is the maximum amount of ethane (C2H6) that can be formed? grams What is the
  78. science

    which is an example of covalent bond? a.chlorine accepts an electron from calcium b. lons in a bar of pure iron are surrounded by a large number of valence electrons c.sodium gives an electron to chlorine to form a stable bond d.there are less than 16
  79. chemistry

    Acids that form ionic solutions will conduct electricity. Acids that form covalent solutions will not conduct electricity. but acids have HYDROGEN in them and hydrogen is a gas is that why the results of the conduction test need to be changed because
  80. General Chemistry (Chem101)

    A chemist mixes two liquids A and B to form a homogeneous mixture. The densities of the liquids are 2.0514 g/mL for A and 2.6678 g/mL for B. When she drops a small object into the mixture, she finds that the object becomes suspended in the liquid; that is,
  81. Chemistry

    A 40-year-old manager, at a prominent legal firm in L.A., experiences abdominal pain post lunch. He goes to the restroom a couple of times, but continues to experience pain and cramps. He eventually decides to get himself examined. While questioning him,
  82. chemistry 101

    Consider the following reaction. CaO (s) + CO2 (g) = CaCO3 (s) A chemist allows 14.4 g of CaO and 13.8 g of CO2 to react. When the reaction is finished, the chemist collects 19.4 g of CaCO3. Determine the limiting reactant, theoretical yield, and percent
  83. Math

    1: select all the pairs of ratios form a proportion. (2 points) A: 1/6, 4/20 B: 7/9, 28/36*** C: 14/19, 21/27 D: 30/80, 6/18 2: Which pair of ratios does NOT form a proportion? (1 point) A: 3/5, 24/40 B: 30/10, 15/5**** C: 9/14, 3/4 D: 7/12, 14/24 3: For
  84. physics

    A car is traveling at a constant velocity of 21 m/s (about 45 mph). The driver sees a fallen tree lying across the road and hits the brakes after a delay (reaction time) of 245 ms. (1 ms = 10-3 s.) Calculate the distance the car travels during this 245 ms
  85. Chemistry

    Does sodium metal react with potassium hydroxide solution? No. It would be a displacement reaction and this only works if the metal is higher in the activity series than the one it wants to displace. Given that potassium is the highest ranked metal (sodium
  86. 5th grade Math

    Can you check my answer? 4. Solve. 6 tenths = ___ thousandths Answer = 600 5. Write 347.392 in expanded form. Answer: (3*100)+(4*10)+(7*1)+(3* 1/10) + (9*1/100)+ (2*1/1000) 9. Write in standard form (number name) for: three thousand four hundred eight-two
  87. Chemistry: check answers

    Please check. Thank you. 2. What is the reduction half-reaction for the following unbalanced redox equation? Cr2O72– + NH4+ Cr2O3 + N2 A.) Cr2O3 -> Cr2O72– B.) Cr2O72– -> Cr2O3 C.) NH4+ -> N2 D.) N2 -> NH4+ 3. Which oxidation-reduction reactions are
  88. CHEM 1B

    Carboxylic acids are stronger acids than alcohols A. This is because the carboxy anion is delocalised. B. This is because the hydrogen atom is delocalised. C. The O-H bond in carboxylic acids is very strong. D. This statement is not true One characteristic
  89. chemistry

    Topic: Iodometry 1. The importance of precipitating the Cu2+ ions using NH3 and redissolving it with acetic acid 2. What are other means of detecting endpoint in iodometry aside from adding starch indicator 1. A pH that is too low leads to excessive
  90. Chemistry

    Propane gas (C3H8) burns completely in the presence of oxygen gas (O2) to yield carbon dioxide gas (CO2) and water vapor (H2O). Write a balanced equation for this reaction. Assuming that all volume measurements occur at the same temperature and pressure,
  91. Chemistry

    Propane gas (C3H8) burns completely in the presence of oxygen gas (O2) to yield carbon dioxide gas (CO2) and water vapor (H2O). Write a balanced equation for this reaction. Assuming that all volume measurements occur at the same temperature and pressure,
  92. health

    what is the importance of nutrition and an active lifestyle? HELP ME HERE! You can expand on this quicky summary. Proper nutrition is important in order to have the nutrients to form bone, muscle, and tissues for proper growth. An active lifestile is
  93. physics

    Part 1 A motorist traveling at 17 m/s encounters a deer in the road 48 m ahead. If the maximum acceleration the vehicle’s brakes are capable of is −5 m/s^2, what is the maximum reaction time of the motorist that will allow her or him to avoid hitting
  94. AP Chemistry

    The reaction of the molecules to produce ethane is C2H4(g) + H2(g) → C2H6(g). A mechanism for this reaction is shown below: (The figures show how the ethene molecule with two hydrogen molecules attached 'binds' to
  95. English

    1.Mom always (____) her glasses down somewhere and then can't find them. 2.No one could believe that Carol had been (___) near the dog the entire time. Use correct form of sit or set 1.sets 2.sitting 1.My grades have (----) a little each semester. 2.My
  96. Biology

    |Question| Living organisms are composed of millions of organic compounds, each having a unique structure. What element is responsible for this huge diversity of molecules? Describe the diversity of structures that can be formed and the properties of this
  97. Chemistry

    Thanks to Dr. Bob for answering all these questions! I always do poorly on conceptual problems. Consider the following equilibrium system at 25°C and select the true statement below: H2PO4−(aq) + SO42−(aq) ↔ HSO4−(aq) + HPO42−(aq) ΔG°rxn > 0
  98. Chemistry

    Hi, I have another question... I need to write a reaction for the preparation of americium by reducing AmF3 with barium vapor at 1100C I'v looked and can't find anything that will help me with this... (I'm preparing for finals, so this might not be my last
  99. Chemistry

    The following reaction has a standard enthalpy of reaction of -146.0 kJ/mol: Cu2O(s) + 1/2 O2(g) -> 2CuO(s) The standard enthalpy of formation of Cu2O(s) is -168.6 kJ/mol. What is the standard enthalpy of formation of CuO(s)?
  100. enviromental

    Completely mixed flow ractor CSTR and plug flow reactor (PFR) may have significantly different efficiencies depending on the reaction order. This problem asks you to compare the relative reactor sizes required to ensure 99.0 % removal of wastewatwer