1. chem plz help!

    the rate of a nuclear reaction can be changed by?? i know adding a catalyst to a normal reaction can but to a nuclear im not sure. increasing temp decreasing pressure adding a catalyst none I suppose it all depends upon how you define a catalyst. Perhaps
  2. Chemistry (Stoichiometry)

    Magnesium powder reacts with steam to form magnesium hydroxide and hydrogen gas. a) Write a balanced chemical equation for this reaction. b) What is the percentage yield if 10.1g Mg reacts with an excess of water and 21.0g Mg(OH)2 is recovered? c) If 24g
  3. chemistry

    A reaction is 50% complete in 34.0 min. 1.) How long after its start will the reaction be 75% complete if it is first order? 2.)How long after its start will the reaction be 75% complete if it is zero order? steps would be helpful
  4. Chemistry 2

    For the gaseous reaction of carbon monoxide and chlorine to form phosgene, (COCl2), calculate each of the following. (a) Calculate S° at 298 K I got -136.76 J/K using delta S = sum of delta S of products minus sum of delta S of reactants which is the
  5. AP Chemistry

    Q - Aluminum metal reacts with zinc(II) ion in an aqueous solution by the following half-cell reactions: Al(s) → Al3+(aq) + 3e− Zn2+(aq) + 2e− → Zn(s) Predict the potential of the cell under standard conditions. Predict whether the
  6. computers

    Dear Sir, thanks very much for your the very detail instruction which I am still working on it. I need some help in using Microsoft Excel to format rational number in the form a/b( not in reduced form :eg. 3/6 but Excel will return value either in reduced
  7. Physical Science

    1. What is molarity of products? I can't decide if it's a. The concentration of the reactants measured in mol/L of solution or b. The concentration of the products measured in mol/L of solution 4. How does pressure relate to reaction rates? I'm stuck
  8. Chemistry

    The molar heat of reaction, H rxn , for the reaction of Ca(s) + 2H+(aq)-> Ca2+(aq) + H2(g) was found to be -550kJ/mol The change Hrxn , for the reaction of CaO(s) + 2H+(aq)-> Ca2+(aq) + H2O(l) was found to be -189kJ/mol Based on these results if the
  9. Physical Science

    1. What is molarity of products? I can't decide if it's a. The concentration of the reactants measured in mol/L of solution or b. The concentration of the products measured in mol/L of solution 4. How does pressure relate to reaction rates? I'm stuck
  10. Pre-Calc

    A wire 100 centimeters in length is cut into two separate pieces (not necessarily equal). ON epiece is bent to form a square and the other to form a circle. Let x equal the length of the wire used to form the square. a. Write the function that represents
  11. Chemistry

    2Mg + O2--->2MgO If more magnesium is added a.the reaction will shift to the right. b.the reaction will shift to the left. c.there will be no shift. and why im confused on why it would happen.
  12. Chemistry

    NH4Cl(s) → NH3(g) + HCl(g) ΔH°=176 kJ/mol At 25 °C, this reaction has a ΔG° of 91.1 kJ/mol. What is the ΔS° of this reaction? I came up with the solution of 0.896 kJ/mol. Is this correct?
  13. chem

    Endothermic reaction equilibrium: BiCl3(aq) + H2O(g) = BiOCl(s) +2HCL(aq) + 2 HCl at a point at which the sollution is colorless and a small minute amoount of BiOCl(s) is observed. for the folowing questions 1to 5: a. state which way the reaction shift in
  14. chem101

    Endothermic reaction equilibrium: BiCl3(aq) + H2O(g) = BiOCl(s) +2HCL(aq) + 2 HCl at a point at which the sollution is colorless and a small minute amoount of BiOCl(s) is observed. for the folowing questions 1to 5: a. state which way the reaction shift in
  15. Science

    1. What is molarity of products? I can't decide if it's a. The concentration of the reactants measured in mol/L of solution or b. The concentration of the products measured in mol/L of solution 4. How does pressure relate to reaction rates? I'm stuck
  16. Science

    1. What is molarity of products? I can't decide if it's a. The concentration of the reactants measured in mol/L of solution or b. The concentration of the products measured in mol/L of solution 4. How does pressure relate to reaction rates? I'm stuck
  17. chem

    when hydrocarbons are burned in a limited amount of air CO as well as CO2 form. When 0.450 grams of a particular hydrocarbon was burned in air, 0.467 grams of CO, 0.733 grams of CO2, and 0.450 grams of H20 were formed. a. What is the empirical formula? I
  18. Chemistry

    If you need to produce 355 grams of oxygen gas (O2) in the electrolysis reaction of water by an electric current. If the reaction is run at 125 degrees Celsius in a reactor volume 22500ml. What is the pressure of the produced oxygen in mm Hg?
  19. biology

    Initially, how do skeletal muscles (the type of muscle attached to bones) make ATP? write the reaction for this procss (Crp +ADP => Cr + ATP) as a 'coupled' reaction, identifying the exergonic and endergonic reactions.
  20. chemistry

    In an experiment, 95.0 mL of 0.225 M silver nitrate was mixed rapidly with 47.5 mL of 0.225 M calcium chloride in a coffee cup calorimeter. If a reaction occurred, was it exothermic or endothermic? If the reaction started at 23.7 °C, what is the final
  21. Chemistry

    Magnesium oxide can be made by heating magnesium metal in the presence of the oxygen. The balanced equation for the reaction is 2Mg(s)+O2(g)¨2MgO(s) When 10.2 g Mg is allowed to react with 10.6 g O2, 11.8 g MgO is collected. Determine the theoretical
  22. Chemistry

    Suppose you tired to carry out a double-replacement reaction by mixing together equal volumes if a solution that contained dissolved NaF and a solution NaCl. Would you expect a reaction, if Si write the balanced chemical equation
  23. chemistry

    having trouble posting but will try again. translate the following verbal description into scientific notation. magnesium ribbon is burned in pure oxygen gas. thanks The reaction forms magnesium oxide (MgO). Se if you can write the balanced reaction.
  24. Chemistry

    Consider the titration of 50mL of 2.0M HNO3 with 1.0M KOH. At eah step, add the following: 0ml, 25ml, 50ml. a) Write a reaction to show the initial reaction b)ICE table c) determine the spectators present after d)Calculate the pH
  25. Chemistry

    In the SN2 mechanism, considering that the nucleophile attacks at the same time as the leaving group leaves, what would the effect of having a hindered (crowded) reaction center be on the rate of the reaction? Would you expect it to react slower or faster
  26. Burnhamthrop Chemistry

    initially 0.25 mol of water vapour and 0.20 mor of carbon monoxide are place in a 1.00 L reaction vessel. at equilibrium spectroscopic evidence shows that 0.10 mol of corbon dioxide is present calculate K for the reaction
  27. Chemistry

    In an experiment, 95.0 mL of 0.225 M silver nitrate was mixed rapidly with 47.5 mL of 0.225 M calcium chloride in a coffee cup calorimeter. If a reaction occurred, was it exothermic or endothermic? If the reaction started at 23.7 °C, what is the final
  28. Chemistry105

    When 50.0 Ml of 1.00 m chi was mixed with 50.0 ml of 1.00 m NaOH in a calorimeter the temperature rose from 25.0 c to 32.0 c calculate the heat change for the reaction assuming that the total volume of the solution is 100.0 ml and the specific heat is 1.00
  29. Chemistry105

    When 50.0 Ml of 1.00 m chi was mixed with 50.0 ml of 1.00 m NaOH in a calorimeter the temperature rose from 25.0 c to 32.0 c calculate the heat change for the reaction assuming that the total volume of the solution is 100.0 ml and the specific heat is 1.00
  30. Chemistry

    Nickel carbonyl has a formula: Ni(CO)4. Nickel carbonyl is produced by the reaction of solid nickel metal with carbon monoxide gas. 1. how do you write a balanced equation for this reaction? 2. How many liters of carbon monoxide gas must be provided to
  31. CHEMISTRY

    Consider the following reaction: 2H2S+SO2=2H20+S(s) A reaction mixture initially containing 0.500M H2S and 0.500M SO2 was found to contain 1.0×10−3M at a certain temperature. A second reaction mixture at the same temperature initially contains H2S
  32. history

    Check my answers please? The Second Great Awakening was a conservative reaction to deism, the expanding frontier, & the industrial revolution. True, it was definitely a reaction to the IR & deism The romantic reaction to rationalism & the industrial
  33. The Nature of Chemical Reactions

    1. Molarity is to moles of solute over liters of solution as molality is to A. molar concentration over molal concentration. B. moles of solute over kilograms of solvent. C. molal concentration over molar concentration. D. moles of solute over moles of
  34. chemistry

    the rate of the following reaction is 0.72 M/s. what is the relative rate of change of each species in the reaction? A+4B -> 2C
  35. chemistry

    Cu2+ + 2e- -> Cu Oxidation reaction Cu -> Cu2+ + 2e Reduction Reaction Do I have these right, or are they backwards?
  36. chem

    what effect does concentration have the reaction time and what effect does it have on the reaction rate?
  37. Chemistry

    Given 1.01 g of H2 in the reaction H2 + 1/2 O2 = H2O. The Delta H for solution is 143 kJ. What is the delta H for the reaction?
  38. Chemistry

    If 60% of a first order reaction was completed in 60 minutes, 50% of the same reaction would be completed in approximately
  39. Chemistry

    A certain reaction has an equilibrium constant of 0.65. Calculate the constant for the reverse reaction.
  40. Rate Laws

    If the initial concentration of AB is 0.210 M, and the reaction mixture initially contains no products, what are the concentrations of A and B after 75 s? The reaction is in the second order: rate=k[AB]^2 The rate constant is k=5.4*10^2 M*s I don't
  41. Science

    The following reaction: 2SO3 (g) ! 2SO2 (g) + O2 (g) has an equilibrium constant equal to 0.23 M. If the following concentrations are present: [SO2] =0.480 M, [O2] = 0.561 M, [SO3] = 0.220 M, is the reaction at equilibrium? If not, which way must it shift
  42. ap chemistry

    a 0.76 mol sample of pcl5 is placed in a 500 ml reaction vessel. what is the concentration of pcl5 when the reaction pcl5(g) ⇀↽ pcl3(g) + cl2(g) has reached equilibrium at 250◦c (when kc = 1.8)
  43. Chemistry

    A mixture of nitrogen gas and hydrogen gas reacts in a closed container to form ammonia gas. The reaction ceases before either reactant is completely consumed. At this stage the container has 3.0 mol each of all three gases; nitrogen, hydrogen and ammonia.
  44. Chemistry

    A mixture of salt way in 13.78g contains CACO3 with gaseous impurity it was heated to a constant mass and the resolve was reacted with H2SO4 to form 6.78g of CASO4. Calculate the percentage purity of the calcium trizoncarbonate four I'm the mixture
  45. English

    Write the verbs in the following sentences. Then identify each verb as bse form (b), present participle with auxiliary verb (pp), simple past form (past), or past participle with auxiliary very (past p), Some of the sentences have two verbs. First
  46. Maths

    How many silver coins, 2cm in diameter and of thickness 2 mm, must be melted to form a showpiece in the form of a frustum of a cone having height 9 cm and radii of the outer circular ends as 5cm and 3cm?
  47. math/ confused!

    What degenerate form or forms of the parabola CANNOT be obtained from the intersection of a plane and a double napped cone? I have to use a diagram and give complete description how to obtain this ( or these) form(s) how would I do this question
  48. math

    on the illinois state tax form, numbers are to be rounded to the nearest dollar. if heather earned $8265.53 at her part-time job, what number would she enter on the form for earmings?
  49. Language arts

    Why are the elements of an autobiographical similar to those of a short story? because the form is about from events in a writer's life*** because most writing forms include narratives because it includes causes and effects because the form is nonfiction
  50. Chemistry

    Which of the following is the best definition of Hess' Law? A. Heat is always released by the decomposition of 1 mole of a compound into its constitute elements. B. The enthalpy of a process is the difference between the enthalpy of the products and the
  51. Chemisty

    For the reaction: 2NO(g) + H2(g) <=> N2O(g) + H2O(g) + energy Write the equilibrium constant expression for the reaction. This reaction takes place at 25°C. At this temperature the concentration of NO is found to be 1.75 mol/L, the concentration of
  52. Chemisty

    For the reaction: 2NO(g) + H2(g) <=> N2O(g) + H2O(g) + energy Write the equilibrium constant expression for the reaction. This reaction takes place at 25°C. At this temperature the concentration of NO is found to be 1.75 mol/L, the concentration of
  53. Science

    For the reaction: 2NO(g) + H2(g) <=> N2O(g) + H2O(g) + energy Write the equilibrium constant expression for the reaction. This reaction takes place at 25°C. At this temperature the concentration of NO is found to be 1.75 mol/L, the concentration of
  54. Chemistry

    The reform reaction between steam and gaseous methane () produces "synthesis gas," a mixture of carbon monoxide gas and dihydrogen gas. Synthesis gas is one of the most widely used industrial chemicals, and is the major industrial source of hydrogen.
  55. chemistry

    Sulfur dioxide and oxygen react to form sulfur trioxide as follows 2SO_2(g) + O_2(g) ⇌ 2SO_3(g) 1 mole of sulfur dioxide is mixed with 0.5 moles of oxygen gas in a 1 L container. There is 0.9 mol of SO_3 at equilibrium. Calculate the following. a)
  56. Chemistry

    Solid copper oxide reacts with ammonia gas according to the following equation: 3CuO + 2NH3 -> 3Cu + N2 + 3H20 50 grams of CuO is placed in an 80L reaction vessel, and the vessel was evacuated. Ammonia gas was then gradually introduced into the vessel,
  57. Spanish (Please Help)

    1. Write the verb form for: yo/hacer. 2. Write the verb form for: ellos/hacer. 3. Write the verb form for: nosotros/hacer. I'm not sure, but I think these are the answers: 1.) Hago 2.) Hagan 3.) Hagamos Thnk You.
  58. Engineering

    Here we consider instead dissolving guns (which we will assume are pure iron) with sulfuric acid. Fe+H2SO4->FeSO4+H2 The characters realize that their hideout has been discovered by the police and they still have a last handgun that weighs 0.25 kg to
  59. Chem

    The entropy of combustion of benzoic acid is zero. This means that... a)combustion is not spontaneous here. b)combustion is spontaneous, however, since the reaction is exothermic. c)combustion is spontaneous, however, since the reaction is endothermic.
  60. CHEMISTRY

    1. Give reasons for your choice. 2. Give reasons for rejecting other options 6. In a chemical reaction at constant temperature, the addition of a catalyst A increases the value of the equilibrium constant. B increases the fraction of molecules with more
  61. Chemistry

    In the gas-phase reaction given below, the [I2] changes from 0.400 M at 0.00 min to 0.200 M at 3.00 min. I2 + Cl2 --> 2 ICl Calculate the average reaction rate in moles I2 consumed per liter per minute. mol/(L·min)
  62. Chemistry

    A first order reaction has a rate constant of 0.0733 s−1. What is the half life for this reaction in seconds? when I plug in the numbers in the formula, my answer was 9.45. But on the computer it says the answer is wrong. How do I find the right
  63. AP Chemistry

    Analysis of a reaction mixture showed that it had the composition 0.43 mol/L N2, 0.541 mol/L H2, and 0.124 mol/L NH3 at 800 K, at which temperature Kc=0.278 for N2(g) + 3H2(g)<->2NH3(g). Calculate the reaction quotient Qc
  64. Chemistry

    Okay, this is a question in several parts that really stumps me: Given the following reaction determine the rate of expression (CH3)3CBr + OH -----> (CH3)3COH + r [(CH3)3CBr] OH Initial reaction rate (mol L-1 sec-1) .10 .10 1.0 x 10 ^ -3 .20 .10 2.0 x
  65. in response to Tabby

    so in order to find out how many moles of O2 are produced from 12 moles of KClO3: 2 mols KClO3 form 3 mols O2 4 mols KClO3 form ? mols O2 Do you double the mols of O2 4 mols KClO3 form 6 mols O2? 6 mols KClO3 form 9 mols O2
  66. Chemistry

    please help! I don't understand any of this. Using the Solubility Rules, write the balanced molecular, total ionic, and net ionic equations (including physical states) for the following: Hints: There is no such thing as an Na3+. Na is in group 1A, so you
  67. chemistry

    When two solutions are mixed and a new color is observed, is this color change an indication that a chemical reaction has occurred? Explain. It is not possible to directly observe chemical bonds breaking and forming during a reaction, molecules and atoms
  68. algebra

    Could you please help me?? point-slope form linear equation y-3 = 3(x+1) what is the equation in standard form of a perpendicular line that passes through (5,1). i think you take 1/3 as slope, reciprocal, I am confused about how to proceed. I know you put
  69. chemistry

    2. What is the percent yield of Mg3N2 if 73.9 g of Mg reacts with 31.6 g of N2 to produce 79 g of Mg3N2 according to the following chemical reaction? (Reaction may or may not be balanced.) mg+n2=Mg3N2
  70. Chemistry

    Carbon monoxide and molecular oxygen react to form carbon dioxide. A 49.0 L reactor at 200°C is charged with 1.14 atm of CO. The gas is then pressurized with O2 to give a total pressure of 3.54 atm. The reactor is sealed, heated to 350°C to drive the
  71. chemistry lab (college level)

    So, this is going to be more like 2 or 3 questions. Here goes. First, what is the net-ionic reaction for Fe (III) + K4Fe(CN)6 be? I've been agonizing over this for HOURS with no answer in sight. (I don't even know what to put down as a product!) Second,
  72. Chemistry

    A mixture of nitrogen gas and hydrogen gas reacts in a closed container to form ammonia gas. The reaction ceases before either reactant is completely consumed. At this stage the container has 3.0 mol each of all three gases; nitrogen, hydrogen and ammonia.
  73. chemistry

    Chemical reaction between solid ammonium chloride and solid barium hydroxide octahydrate 2NH4Cl(s)+Ba(OH)*8H2O(s)->2NH3(aq)+BaCl2(aq)+10H2O(l) the change in heat for this reaction is 54.8kJ how much energy would be absorbed if 24.9g of NH4Cl reacts
  74. chemistry

    20.0 mL of a 0.125 M solution of potassium iodide is added to 15.0 mL of a 0.235 M solution of lead (II) nitrate. A reaction occurs via the balanced equation below: 2KI(aq)+ Pb(NO3)2(aq) --> 2KNO3(aq) +PBI2(ppt) How much product can theoretically be
  75. Organic Chemistry

    Does anyone know where I might find a step-by-step reaction mechanism for a polymer condensation reaction involving Hexamethylenediamine with Adipoyl Chloride (thus synthesizing Nylon 66)? If not, can anyone help list the steps that take place and why? Any
  76. Chemistry

    One mole of N2 and three moles of H2 are placed in a flask at 375 C. Calculate the total pressure of the system at equilibrium if the mole fraction of NH3 is 0.21. The Kp for the reaction is 4.31*10^4. I assume this to be the reaction N2 + 3H2 --> 2NH3
  77. organic chemistry

    Instead of using 1-propanol or 2-pentanol, a student decided to conduct the same reaction (using Sodium Bromide and Sulfuric Acid) you did starting with 2,4-dimethyl-3-pentanol instead. What product(s) would you predict for this reaction? Show a mechanism
  78. science

    The reaction 2SO + O2 ¨ 2SO3 is exothermic. (a) How will a rise in temperature affect the yield of SO3 in an equilibrium mixture of the three gases? (b) Will an increase in pressure raise or lower the yield? (c) In what possible way can the speed of the
  79. Chemistry

    One mole of N2 and three moles of H2 are placed in a flask at 375 C. Calculate the total pressure of the system at equilibrium if the mole fraction of NH3 is 0.21. The Kp for the reaction is 4.31*10^4. I assume this to be the reaction N2 + 3H2 --> 2NH3
  80. chemistry

    Which of the following experimental conditions describe a reaction which is kinetically controlled? These conditions do not describe kinetic control. ΔG = -100 kJ/molrxn; there is no observable reaction when reactants are mixed. ΔG = +100
  81. Science help

    Will someone please check my work for me? Molecules involved in a chemical reaction must meet to react. What is this concept called? entropy enthalpy collision theory<---- reaction rate 2. Which of the following equations is used to describe reaction
  82. chemistry

    Calculate enthalpy change of reaction for the combustion of gaseous ethanol. C2H5OH + 3O2 >> CO2 + 3H2O. Using standard molar enthalpies of formation. C2H5OH -235.3 ( it's negative sign) CO2 -393.5 H2O -241.8 (1) Calculate the enthalpy change of
  83. Chemistry

    How would you exactly start the first problem? My thermodynamic skills is a bit rusty. I am assuming I have to use ΔH°f under the given reaction..? But then..we barely covered ΔG° in class. Am I to use this equation, ΔG° = ΔH° - T
  84. chemistry DR BOB

    is this the answer to B ) C2H5OH(liq)+ 3O2(g) --> 2CO2(g) +3H2O(liq) In winemaking, the sugars in grapes undergo fermentation by yeast to yield CH3CH2OH and CO2. During cellular respiration, sugar and ethanol are "burned" to water vapor andCO2. Write a
  85. chemistry DR BOB!

    is this the answer to B ) C2H5OH(liq)+ 3O2(g) --> 2CO2(g) +3H2O(liq) In winemaking, the sugars in grapes undergo fermentation by yeast to yield CH3CH2OH and CO2. During cellular respiration, sugar and ethanol are "burned" to water vapor andCO2. Write a
  86. Chemistry

    Draw structural formula for each reaction and state the type of reaction that is occuring: a. 4-nonene and fluorine gas b. hexane and oxygen gas c. pentanol and butanoic acid d. propene and hydrogen gas
  87. Chemistry

    Air bags in cars are inflated by the sudden decomposition of sodium azide (NaN3) by the following reaction. 2 NaN3(s) −→ 3 N2(g) + 2 Na(s) What volume of N2 gas, measured at 1.30 atm and 88.0◦C, would be produced by the reaction of 65.0 g of NaN3?
  88. Chemistry

    H2O is the same thing as HOH correct? Does it matter which one you use in a Double Replacement Reaction? To me personally, HOH is easier to balance. Would I get marked down if I left HOH in my balanced reaction, if technically speaking, both are
  89. AP Chemistry

    THe following reaction is carried out in a bomb calorimeter: 4NH3(g )+ 5O2(g) ---> 4NO(g) + 6H20 The calorimeter constant is 45.0kJ/K. WHen 34.0g of NH3 are reacted in the calorimeter, the temperature rises by 10.0C. What is the change in energy, dE
  90. ap chem

    Analysis of a reaction mixture showed that it had the composition 0.417 mol/L N2, 0.539 mol/L H2, and 0.127 mol/L NH3 at 800 K, at which temperature Kc = 0.278 for N2(g) + 3H2(g) *) 2NH3(g) . Calculate the reaction quotient Qc .
  91. Chemistry

    Draw structural formula for each reaction and state the type of reaction that is occuring: a. 4-nonene and fluorine gas b. hexane and oxygen gas c. pentanol and butanoic acid d. propene and hydrogen gas
  92. Chem

    This is the problem: In a 1-L beaker, 203 ml of 0.307 M ammonium chromate was mixed with 137 ml of 0.269 M chromium (III) nitrite to produce ammonium nitrite and chromium (III) chromate. Write the balanced chemical reaction occuring here. If the percent
  93. Chemistry

    Nitrogen and hydrogen react to form ammonia. Consider the mixture of N2 and H2 in a closed container. In this container there are 6 diatomic molecules of hydrogen and 6 diatomic molecules of nitrogen. assuming the reaction goes to completion draw a
  94. college chemistry

    Predict two new ionic compounds that may form after you mix these sodium phosphate and calcium nitrate solutions. Write a balanced equation to show which ions would collide and what compound will form.
  95. Chemistry Equation(again!)

    Posted by chrissy on Saturday, January 6, 2007 at 1:23pm. In a lab expirement you add copper(II)nitrate to pure zinc. Write a balanced equation for this expirement and predict if a reaction will occur. For Further Reading Chemistry Equation - DrBob222,
  96. Chemistry - Liquid Methane?

    "The planets Uranus and Neptune are so far from the Sun that temperatures are low enough for atmospheric methane, CH4, to condense and form clouds. How is it possible for methane, a nonpolar substance, to exist in this liquid state?" I want to say it's
  97. chemistry

    True or False: 1. A rate law can be written from the molecularity of the slowest elementary step. 2.The final rate law can include intermediates. 3.The rate of a reaction is dependent of the fastest step in the mechanism. 4.A mechanism can never be proven
  98. maths/probability

    q/ in a soccer match where team a has form figures of W/2 D/1 L/7 and team b has form figures of W/3 D/4 L/3 whatis the likely outcome of the match percentage wise for team a W/ L/ D/ ? if team a has form figures of W/2 D/1 L/7 and team b W/3 D4 L/3 you
  99. Chemistry

    Iron pyrite (FeS2) is the form in which much of the sulfur exists in coal. In the combustion of coal, oxygen reacts with iron pyrite to produce iron(III) oxide and sulfur dioxide, which is a major source of air pollution and a substantial contributor to
  100. ELA (My last question of the day)

    I think it is b or d. What is the BEST description and explanation for the underlined word in this sentence? The barking dog woke the entire neighborhood with his incessant noise. A) Barking is an adjective form being used to modify the dog. B) Barking is