1. chemistry

    A system performs 120J work with no heat supplied to it. Calculate the change in internal energy of the system.

    asked by jaycab on January 23, 2011
  2. science

    Explain how heat is transferred between a hot and a cold object by conduction — for example, a warm foot on a cold floor.

    asked by Boobear on April 22, 2013
  3. Chemistry

    A system releases 647 kJ of heat and does 150 kJ of work on the surroundings. What is the change in internal energy of the system?

    asked by just need help on April 19, 2019
  4. Physics

    Which of these types of motors or engines are heat engines? a. an automobile engine b. an electric motor c. a steam turbine

    asked by Anonymous on January 2, 2011
  5. chemistry

    The heat of vaporization of liquid water at 373 K is 40.7 kJ/mol. The value of the enthalpy change when 2.00 g of steam condenses at 373 K is?

    asked by Anonymous on November 28, 2010
  6. chemistry

    A total of 506 J of heat are added to 50.0 g of water initially at 15.0 degrees Celsius. What is the final temperature of the water?

    asked by rachel on September 27, 2012
  7. Chemistry

    Given the following thermochemical equation: 2 SO2 + O2 => 2 SO3 + 4300 kJ What is the heat change in kJ accompanying the production of 43.0 grams of SO3?

    asked by Anonymous on December 17, 2018
  8. chemistry

    how much heat, in kilojoules, must be added to 178 grams of water to increase the temperature of the water by 50 degrees celisus?

    asked by ch on April 21, 2010
  9. chemistry

    phsophorous trichloride and phosphorous pentachloride equilibrate in the presence of molecular chlorine according to PCl3 (g) +Cl2 (g)->PCl5 (g) Kc = 2.01 at 500k If a 1.000L reaction vessel is charged with .300 mol of PCl5(g) and allowed to equilibrate at

    asked by james on October 1, 2015
  10. world history

    Which of the following statements is true of the Ice Age that began 150,000 years ago? A. Many humans enjoyed high levels of nutrition and long days of leisure. B. Culture varied greatly throughout the inhabited world. C. Humans didn't use highly

    asked by firedup on November 14, 2011
  11. chemistry

    how much heat is needed to change 20 g of solid water at 0 c to liquid water at 15 c?

    asked by Shawnie on April 6, 2011
  12. Chemistry

    Explain why when you microwave a plate of steak and potatoes, the potatoes heat up first.

    asked by Kaj on May 24, 2010
  13. chemistry

    how much heat is absorbed as 12g of hydrogen warms from 25 degree C to 78 degree C?

    asked by Viviana on December 6, 2011
  14. Chemisty

    Determine how many calories are need to heat 30 grams of water from 10 degrees C to 30 degrees C

    asked by Ali on January 30, 2013
  15. Chemistry

    How much heat is given up when 20 g of steam at 100 deg C is condensed and cooled to 20 deg.C?

    asked by Mary on February 23, 2010
  16. Chemistry

    If 8.00 kJ of heat are added to 200. g of water at 20.0 ◦C, what is the final temperature of the water

    asked by Ponyboy on September 16, 2010
  17. muniz

    how much heat must be removed from 20g of water at 130 c to make 20 g water at -22 c

    asked by ali on January 14, 2013
  18. Science

    Is sulfur a good conductor or poor conductor of heat and electricity?

    asked by Day on May 11, 2015
  19. Chemistry

    What is the heat of combustion of ethane, C2H6, in kilojoules per mole of ethane?

    asked by Jessica on June 19, 2013
  20. Chemistry

    Why is the heat of neutralization between HCL and NaOH is higher than CH3COOH and NaOH

    asked by Christian Dadzie on August 27, 2016
  21. science

    a change in the state of matter caused by a change in heat or pressure

    asked by kathy on May 4, 2011
  22. chemistry

    How much heat would be produced by reacting 1.82 grams of HCl with 2.00 grams of NaOH?

    asked by Sarah on November 18, 2010
  23. Physical Science

    22. Why does a heat pump need an external source of energy (such as electrical energy)?

    asked by Alex on March 8, 2014
  24. k park

    how much heat must be removed froms 20 g of water at 130 c to make 20 g water at -22 c

    asked by ali on January 14, 2013
  25. Science at National University OF Samoa

    2-bromobutane heat with 2M NaOH. What is the observation and the chemical reaction for the reaction?

    asked by Terry Manu on April 13, 2016
  26. chemistry

    What is the heat of combustion of ethane, C2H6, in kilojoules per mole of ethane?

    asked by superman on January 27, 2013
  27. Heat and property matter

    What is the specific heat of a substance at its boiling point or melting point

    asked by Hammed on April 23, 2015
  28. chemistry

    If 8.00 kJ of heat are added to 200. g of water at 20.0 C, what is the final temperature of the water?

    asked by jane on January 17, 2011
  29. Energy Transfer and Heat flow

    1. What is entropy? 2.With every energy transfer, what form of energy is always released? I think 2 is Heat?

    asked by Stephanie on March 22, 2013
  30. Energy Transfer and Heat flow

    1. What is entropy? 2.With every energy transfer, what form of energy is always released? I think 2 is Heat? not sure about 1

    asked by Anonymous on March 24, 2013
  31. Chemistry

    How much water at 10°C can be heated to 40°C by the heat evolved from cooling 300g of water from 80°C to 40°C?

    asked by Kiven on November 29, 2016
  32. Science

    Air is a good conductor of heat. true false I think it is false...?

    asked by Cassie on April 8, 2013
  33. physics

    Is it easier to exchange heat between a thermometer and air or between a thermometer and water.

    asked by college on July 3, 2010
  34. organic chemistry

    what do we need to consider when choosing a solvent to heat under reflux? Would one be the boiling point of the solvent?

    asked by Anonymous on March 12, 2013
  35. Chemistry

    what is the standard heat formation of F3O4. i know for F2O3 is -824.2. is this the same for F3O4????

    asked by school girl on December 3, 2009
  36. chemistry

    How do you calculate Ke for 2 SO2 (g) + O2 (g) ↔ 2 SO3 (g) + heat [0.0500] [0.0500] [0.103]

    asked by Kalia on October 11, 2010
  37. Chemistry

    When 24.0 cal of heat is added to 18.5 g of aluminum at 19.0 ∘C, what is the final temperature of the aluminum?

    asked by Christina on September 14, 2015
  38. Thermodynamics

    Can I have any energy transfer as heat transfer that is 100% available? Explain with equation

    asked by shane on September 3, 2015
  39. science

    describe the relationship among energy absorption, heat energy, and temperature

    asked by teresa on September 5, 2017
  40. general chemistry

    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

    asked by Nora on October 23, 2010
  41. Science

    1.)Why is Earth’s temperature just right for life? (1 point) A.)Earth’s core is hot enough to heat Earth’s surface. B.)Earth’s magnetic field creates suitable temperatures on Earth’s surface. C.)Earth’s crust is warmed by heat from the sun.

    asked by YRN DJ on December 7, 2015
  42. french

    can someone read my story that knows french well? can you please check it for mistakes. Here is the english and french version of it. Jean Paul n'a pas aimé partager ses choses. Par exemple, un jour il est allé à la plage. Il a apporté trois pelles,

    asked by stacey on June 18, 2009
  43. chemistry

    1. if 15.0mL of 4.5 M NaOH are diluted with water to a volume of 500mL, what is the molarity of the resulting solution? 2. in a acid-base titration, 33.65mL of an 0.148 M HCL solution were required to neutralize 25.00mL of a NaOH solution. What is the

    asked by djella on October 25, 2011
  44. accounting

    Logan Products computes its predetermined overhead rate annually on the basis of direct labor-hours. At the beginning of the year, it estimated that 38,000 direct labor-hours would be required for the period’s estimated level of production. The company

    asked by sally on September 8, 2012
  45. physics

    You and your friend, both of mass 70 kg, are playing catch with a frisbee on frictionless ice. Initially, you are both at rest. You throw a 0.175 kg frisbee at 10 m/s horizontally at your friend, who catches it. After they catch the frisbee, what is the

    asked by HELP ME...uRGENT! on April 2, 2013
  46. physics

    You and your friend, both of mass 70 kg, are playing catch with a frisbee on frictionless ice. Initially, you are both at rest. You throw a 0.175 kg frisbee at 10 m/s horizontally at your friend, who catches it. After they catch the frisbee, what is the

    asked by rohit on April 1, 2013
  47. Physics

    a 60 kg person falls off a 15 kg sled moving at 2 m/s. The person doesn't move after falling. Assuming no friction with the ice, and not other net forces acting on the sled, what is the change in velocity of the sled after the person falls off.

    asked by Sophie on December 16, 2010
  48. physics

    Two skaters, one with mass 62 kg and the other with mass 45 kg, stand on an ice rink holding a pole of length 10 m and negligible mass. Starting from the ends of the pole, the skaters pull themselves along the pole until they meet. How far does the 45 kg

    asked by Jason on November 1, 2011
  49. 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

    asked by audrey12 on November 27, 2012
  50. 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

    asked by Audrey12 on November 27, 2012
  51. physics bobpursly help still having trouble

    A satellite in a circular orbit around earth with a radius 1.019 times the mean radius of the earth is hit by an incoming meteorite. A large fragment m=60 kg is ejected in the backwards direction so that it is stationary with respect to the earth and falls

    asked by Andy on December 2, 2009
  52. Math

    Emily wants to make a regtangular model with a height of one connecting cube. she wants to make the model in exactly 2 different ways. how many connecting cubes could Emily use to make the model in only 2 ways. A6, B12, C16, D18

    asked by Dan on January 12, 2016
  53. math

    a manufacturer's cost is given by C= 300 cube root of n + 1200, where c is the cost and n is the number of parts produced. find the cost when 8 parts are produced. help please!!!! We have C = 300n1/3 +1200 Substitute 8 for n to get C = 300*81/3 +1200 You

    asked by tay on October 13, 2006
  54. Geometry

    I realize I'll get a reply in the morning so... A squash ball must have a diameter either 0.5 mm either above or below 40 mm. a) What is the minimum and maximum surface area of a squash ball? Express answer to nearest square millimetre. Minimum: 4902

    asked by Lucina on January 12, 2015
  55. Science

    The amount of friction exerted when an object moves across a surface depends on how the object and the surface rub together. For which of these surfaces will friction be greatest when a block of wood slides across it? a)wet ice; b)glass mirror; c)thick

    asked by Micaela on January 11, 2012
  56. Physics. PLEASE HELP!!

    Two ice skaters hold hands and rotate, making one revolution in 7.6 s. Their masses are 15 kg and 50 kg, and they are separated by 4.6 m. Find the angular momentum of the system about their center of mass. Answer in units of J · s Find the total kinetic

    asked by Amber on April 25, 2012
  57. Physics. PLEASE HELP!!

    Two ice skaters hold hands and rotate, making one revolution in 7.6 s. Their masses are 15 kg and 50 kg, and they are separated by 4.6 m. Find the angular momentum of the system about their center of mass. Answer in units of J · s Find the total kinetic

    asked by Amber on April 23, 2012
  58. science

    A drinking glass at a crime scene contains a clear colorless liquid that may be water or alcohol. As the investigator, you know that the densities of alcohol, water, and ice are 0.79g/mL, and 0.92/mL. Design a simple method to determine the identity of the

    asked by Brianna on September 16, 2014
  59. Science

    which of the following is an example of a chemical change? A)Iron changes when heated B)Gas bubbles form in boiling water C) Balls of wax form when melted wax is poured into ice water. D)A gas forms when vinegar and baking soda are mixed My Choice D

    asked by Appreciated Help on September 30, 2015
  60. Scienc

    The dissolution of ammonium nitrate in water changes the temperature of water from 21C to - 1C(ice). If the molar enthalpy of ammonium nitrate is 25.7kj/mol. Determine the mass of ammonium nitrate that was dissolved

    asked by Marc on May 23, 2016
  61. Physics

    A straight horizontal rope is towing a 5.52 kg toboggan across frictionless ice. A 2.76 kg radio is on top of the toboggan with a coefficient of static friction of 1.50 between the toboggan and radio. In order to prevent the radio from slipping, what is

    asked by Jim on October 13, 2016
  62. physics

    the steam point and ice point of a mercury thermometer are wrongly marked as 92 degree Celsius and 2 degree Celsius respectively.the correct temperature read by this thermometer is?

    asked by ashu on April 23, 2012
  63. science

    Ice cubes of total mass 6.00 grams have temperature -4.0°C. Then they are placed in 50.0 grams of water at 20.0°C in an insulated foam cup. What is the equilibrium temperature of the water inside the cup?

    asked by jay on December 2, 2015
  64. Chemistry

    How many grams of ice are needed to cool 250 ml of water from 75 degrees Celsius to 5 degrees Celsius? (m_ice * 6.01kJ) + (m_ice * 4.18J/g°C * (5-75°C) = -[250mL * 4.18J/g°C * (5-75°C)] ???

    asked by Mikey on September 5, 2016
  65. Physics

    A person is making homemade ice cream. She exerts a force of magnitude 23 N on the free end of the crank handle, and this end moves in a circular path of radius 0.35 m. The force is always applied parallel to the motion of the handle. If the handle is

    asked by Eric on February 25, 2008
  66. physics

    An ideal gas (volume 1.1m3 , pressure 101500 Pa, temperature 290 K) undergoes an isothermal process during which it absorbs 2000 J of heat. How much did the entropy of the system increase?

    asked by Nadya on November 18, 2010
  67. chemistry

    Determine the amount of heat (in kJ) given off when 2.07 multiplied by 104 g of ammonia are produced according to the following equation. Assume that the reaction takes place under standard-state conditions at 25.0°C. N2(g) + 3 H2(g) 2 NH3(g) ΔH°rxn =

    asked by jamie on September 22, 2008
  68. Science

    If your house is heated by a furnace that blows hot air into the rooms, you are depending on the process of ______ to stay warm. Choices are: convection, radiation,conduction, heat

    asked by Grant on October 2, 2007
  69. chemistry

    Suppose that 0.450 of methane,CH4(g) , is reacted with 0.600 of fluorine, F2(g), forming CF(g) and HF(G) as sole products. Assuming that the reaction occurs at constant pressure, how much heat is released?

    asked by ricardo on October 24, 2012
  70. Science

    Which of the following is an example of heat transfer by radiation? A. Wind currents. B. A pot of water on a boiling stove. C. A bare foot on a hot sidewalk. D. A microwave oven heating food. Is it B?

    asked by Phebe on April 16, 2019
  71. science

    How much heat is gained (in Joules) by the water (qwater) when a chemical reaction takes place in 100.0 mL aqueous solution and has a temperature increase of 13.26 °C? (Remember cwater = 4.180 J/°Cg)

    asked by brittany sheats on November 17, 2013
  72. Chemistry

    How much heat is absorbed/released when 35.00 g of NH3(g) reacts in the presence of excess O2(g) to produce NO(g) and H2O(l) according to the following chemical equation? 4NH3(g)+5O2(g)--->4NO(g)+6H2O(l) DeltaH=1168kj

    asked by Daqa on March 18, 2010
  73. science

    The type of heat transfer called convection happens as a result of: a. electromagnetic waves b. the direct contact of particles in a substance c. the actual motion of a fluid in the form of currents d. All of the above I think it's C.

    asked by Red on April 3, 2014
  74. Science

    Which of the following is an example of heat transfer by radiation? A. Wind currents B. a pot of water boiling on the stove C. a bare foot on a hot sidewalk D. a microwave oven heating food I think B? Not sure?

    asked by Amber on December 28, 2015
  75. college physics

    An ideal gas (volume 1.1m3, pressure 103600 Pa, temperature 400 K) undergoes an isothermal process during which it absorbs 2000 J of heat. How much did the entropy of the system increase?

    asked by Nick on November 19, 2010
  76. Chemistery

    How much heat is contained in 4 liter of liquid methanol (CH2OH) when it is completely combusted (excess oxygen) to form carbon dioxide and water. the density of metanol is 0.7918 g/ml.

    asked by Lin on October 30, 2010
  77. Physics

    A windowpane is half a centimeter thick and has an area of 1.0 m2. The temperature difference between the inside and outside surfaces of the pane is 15° C. What is the rate of heat flow through this window? (Thermal conductivity for glass is 0.84

    asked by Jesse on December 19, 2010
  78. college physics

    An ideal gas (volume 1.1m3, pressure 103600 Pa, temperature 400 K) undergoes an isothermal process during which it absorbs 2000 J of heat. How much did the entropy of the system increase?

    asked by Nick on November 19, 2010
  79. Chemistry

    Suppose you wanted to heat a mug of water (250 mL) from room temperature 25 C to 100 C to make a cup of tea. How much energy (in units of calories and joules) would you need from your microwave?

    asked by David on January 22, 2012
  80. chemistry

    When you add 0.320 g of sodium metal to an excess of hydrochloric acid, you find that 3330 J of heat are produced. What is the enthalpy of the reaction as written below? 2Na(s) + 2HCl(aq) --> 2NaCl(aq) +H2(g

    asked by Catherine on March 9, 2015
  81. chemistry

    When you add 0.567 g of sodium metal to an excess of hydrochloric acid, you find that 5890 J of heat are produced. What is the enthalpy of the reaction as written below? 2Na(s)+2HCl(aq)=2NaCl(aq)+H2(g)

    asked by lex on April 13, 2016
  82. chemistry 106

    Determine the amount of heat (in kJ) given off when 2.23 multiplied by 104 g of ammonia are produced according to the following equation. Assume that the reaction takes place under standard-state conditions at 25.0°C. N2(g) + 3 H2(g) 2 NH3(g) ΔH°rxn =

    asked by Tanisha on March 3, 2010
  83. Physics

    A 0.300 kg iron horseshoe that is initially at 550°C is dropped into a bucket containing 19.4 kg of water at 21.1°C. What is the final equilibrium temperature (in °C)? Neglect any heat transfer to or from the surroundings. Do not enter units.

    asked by Anonymous on April 25, 2016
  84. college physics

    An ideal gas (volume 1.1m3, pressure 103600 Pa, temperature 400 K) undergoes an isothermal process during which it absorbs 2000 J of heat. How much did the entropy of the system increase?

    asked by Kristy on November 11, 2010
  85. PhysicsI

    A windowpane is half a centimeter thick and has an area of 1.0 m2. The temperature difference between the inside and outside surfaces of the pane is 15° C. What is the rate of heat flow through this window? (Thermal conductivity for glass is 0.84

    asked by Fred on July 24, 2014
  86. math

    The number has 6 digits. The nuber is less than 300000. 10 is a factor of the number. The hundred thousands and ten thousands digit are the same and are odd. The tens digit is a cube number and is one more than the thousands digit. The sum of the hundreds

    asked by sania on October 29, 2016
  87. Chemistry

    A 0.170-mole quantity of CoCl2 is added to a liter of 1.20 M NH3 solution. What is the concentration of Co2 ions at equilibrium? Assume the formation constant (Kf) of Co(NH3)62 is 5.0× 1031 M–6. I don't really know how to start. At first I thought about

    asked by Alexis on April 14, 2014
  88. MECHANICS

    CARS A 7B ARE 60 M APART TRAVELLING RESP AT THE CONST SPEED OF 32 AND 24 KPH ON AN ICE COVERED ROAD .KNOWING THAT 45 SEC AFTER DRIVER APPLIES HIS BRAKES TO AVOID OVERTAKING CARB ,THE 2 CARS COLLIDE DETERMINE UNIFORM DECELLERATION OF CAR A RELATIVE VEL OF

    asked by HARSHITH on November 9, 2010
  89. pre calc 12

    During intermission, at a hockey game, small foam hockey pucks are launched from a height. How long is a puck in the air if a student in the stands catches it on its way down 12m above ice lvl? The model for the vertical motion of the puck can be

    asked by AMANSANDHUWILLDIE!!! on March 29, 2016
  90. Writing

    My course program is Bachelor of Science in Information technology. Throughout this course, you will be asked to reflect on various topics in journal entries. Your Topic 2 entry will be about your program of study. The purpose of writing the journals is to

    asked by Alvis on May 29, 2018
  91. Finite Math

    If everyone had the same body proportions, your weight in pounds would vary directly with the cube of your height in feet. Assume the average height and weight of a female in your math class is 5'5" and 135 pounds. Use this information to write a variation

    asked by MacKayla on February 5, 2019
  92. math

    If everyone had the same body proportions, your weight in pounds would vary directly with the cube of your height in feet. Assume the average height and weight of a female in your math class is 5'5" and 150 pounds. Use this information to write a variation

    asked by montrey sanon on January 25, 2012
  93. Science(Stuff to do like with magnets!)

    1. A positively charged test object is moving toward the positive source charge in an electric field. What happens next??? A. its potential energy decreases. B. Its potential energy increases. C. Its potential energy stays the same. D. Its potential energy

    asked by Guest user on September 15, 2014
  94. Chemistry

    For an enthalpy lab, why would calculated value differ from the theoretical value (in percent error) for the heat reaction of Mg/HCl and MgO/HCl

    asked by Liz on July 21, 2014
  95. physics

    water has a specific heat of 4184 j(kg K). How much energy is needed to increase the temperature of a kilogram of water 5 degrees celcius?

    asked by jesse bess on March 3, 2011
  96. chem

    A lead fishing weight with a mass of 57 g absorbs 146 cal of heat.If its initial temperature is 48^C, what is its final temperature?

    asked by Anonymous on October 20, 2010
  97. chemistry

    a 2kg block of iron is given 10kj of energy and its temperature rises by 10c. what is the specific heat capacity of iron?

    asked by sue on September 22, 2011
  98. chemistry

    a 2kg block of iron is given 10kj of energy and its temperature rises by 10c. what is the specific heat capacity of iron?

    asked by sue on September 22, 2011
  99. Physics

    Pretend the hot brick extracts heat from the cold brick and becomes hotter. Would this violate the Law of Conservation of Energy?

    asked by Katie on December 9, 2012
  100. science

    a lead bullet at 100C strikes a steel plate and melts. what was its maximum speed? the specific heat of lead is 0.13 kJ/kg C

    asked by Anonymous on September 21, 2012