Questions asked by Gabriel

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• How many mole of Bi atoms are needed to combine with 1.58 O atoms to make Bi2O3?
  
• How much heat, in joules and in calories, must be removed from 1.75 mol of water to lower its temperature from 25 degree celsius to 15 degree celsius?
  
• A 50.0 g piece of metal at 100.0 degree C was plunged into 100.0 g of water at 24.0 degree C. The temperature of the resulting mixture became 28.0 degree C. (a) How many joules did the water absorbs (b) How many joules did the metal lose?
  
• A sample of nitrogen has a volume of 880 mL and a pressure of 740 torr. What pressure will change the volume to 550 mL at the same temperature?
  
• A balloon has a volume of 2.50 L indoors at 22 degree C. If the balloon is taken outdoors on a cold day when the air temperature is -15 degree C (5 degree F), what will its volume be in liters? Assume constant air pressure within the balloon.
  
• A sample of gas has a pressure of 854 torr at 285 degree C. To what Celsius temperature must the gas be heated to double its pressure if there is no change in the volume of the gas?
  
• A sample of helium at a pressure of 745 torr and in a volume of 2.58 L was heated from 24.0 to 75.0 degree C. The volume of the container expended to 2.81 L. What was the final pressure (in torr) of the helium?
  
• A sample of argon with a volume of 6.18 L, a pressure of 761 torr, and a temperature of 20.0 degree C expended to a volume of 9.45 L and a pressure of 373 torr. What was its final temperature in degree C?
  
• How many milliters of oxygen are required to react completely with 175 mL of C4H10 if the volumes of both gases are measured at the same temperature and pressure? The reaction is 2C4H(g) + 13O2(g) --> 8CO2(g) +10H2O(g)
  
• What volume in liters does 1.67 g of N2 occupy at 22.0 degree C and 756 torr?
  
• What pressure (in torr) is exerted by 10.0 g of O2 in a 2.50 L container at a temperature of 27 degree C?
  
• A sample of carbon dioxide has a volume of 26.5 mL at 20 degree C and 624 torr. How many grams of CO2 are in the sample?
  
• Propylene, C3H6, reacts with hydrogen under pressure to give propane, C3H8: C3H6(g) + H2(g) -----> C3H8(g) How many liters of hydrogen ( at 740 torr and 24 degree C) react with 18.0 g of propylene?
  
• What are the mole fraction and the mole percent of oxygen in exhaled air if P (subscript of O2) is 116 torr and a P (subscript of total) is 788 torr? I not sure if the question makes sense.
  
• Identify the substance oxidized, the substance reduced, the oxidizing agent, and the reducing agent? 2HNO3 + 3H3AsO3 -----> 2NO + 3H3AsO4 + H2O
  
• What is the molarity of a solution made using 2.19 g of KI dissolved in enough water to make 266 mL of solution?
  
• How many grams of AgNO3 are needed to prepare 593.4 mL of 0.0260 M AgNO3 solution?
  
• A student found that the sulfate ion concentration in a solution of Al2(SO4)3 was 0.22 M. What was the concentration of Al2(SO4)3 in the solution?
  
• A student prepares a solution of hydrochloric acid that is approximately 0.1 M and wanted to determine its precise concentration. A 25.00 mL portion of the HCl solution is transferred to a flask, and after a few drops of indicator are added, the HCl ?
  
• Write a balanced chemical equation for the complete combustion (in the presence of excess oxygen) of: How do you start? (a) C12H26 (a component of kerosene) (b)
  
• Enter chemical equations for the reaction of oxygen with the following. All reactions form solid oxides. Include physical states in your answers. Use minimal integer numbers for coefficient inputs (a) zinc (b) aluminum How would I start a question like?
  
• A mixture of gases contains 319 torr N2, 273 torr O2, and 285 torr Ar. What is the total pressure of the mixture?
  
• At 35°C a sample of a fixed amount of ideal gas occupies 150. mL at a pressure of 3.50 atm. What would be its volume at the same pressure and 105°C?
  
• The pressure in a 5.75 L container of 48.0 g of bromine gas at 100.0°C is ....... What is the pressure in atm?
  
• What would be the volume of a 13.70 g sample of the noble gas krypton at STP?
  
• A mixture contains 10.0 g each of the three gases nitrogen, oxygen, and argon. What is the mole fraction of nitrogen in the mixture?
  
• What volume in liters does 0.136 g of O2 occupy at 20.0 degree C and 748 torr?
  
• A chemist isolated a gas in a glass bulb with a volume of 255 mL at a temperature of 25.0 degree C and a pressure ( in the bulb ) of 10.0 torr. The gas weighed 12.1 mg. What is the molar mass of this gas?
  
• What are the mole fraction and the mole percent of oxygen in exhaled air if P (subscript of O2) is 116 torr and P ( subscript total) is 788 torr?
  
• Under conditions in which the density of #CO_2# is 1.96gL and that of #N_2# is 1.25 gL , which gas will effuse more rapidly? What will the ratio of the rates of effusion of #N_2# to #CO_2#?
  
• Write a balance equation for the combustion of isoprene, C5H8, in an abundant supply of oxygen?
  
• How to write a balance chemical equation for the reaction of molecular oxygen with radium metal to form oxide?
  
• When nitrogen gas reacts with hydrogen gas to form ammonia, 92.38 KJ of heat are given off for each mole of nitrogen gas consumed, under constant pressure and standard conditions. What is the value of H degree for the reverse of the reaction shown.?
  
• A cup of tea containing 400.0 g of liquid at 20.0 degree C was heated. If 58.5 kJ of heat was added to the tea, what would be the final temperature? Assume that the specific heat is the same as that of water( 4.18 J g c)
  
• A sample of gas in a cylindrical chamber with a removable piston occupied a volume of 6.414 liters when the pressure was 850 torr and the temperature was 27.2 degree C. The Pressure was just readjusted to 4423 torr by moving the piston. ?
  
• Considered the reaction: N2(g) + 2NO2(g) for which (delta H) = +67.6KJ. What is the enthalpy change in KJ for the production of 23.0 g NO2?
  
• A 35 degree C sample of a fixed amount of ideal gas occupies 420 mL at a pressure of 1.25atm. What will the volume be at a pressure of 0.900 atm ? Note: The temperature remains constant
  
• Which property of light waves specifies the color of light? Which is related to the energy of light?
  
• Calculate the energy, in joules, of a photon of green light having a wavelength of 562nm?
  
• How many electrons are in the valence shells of (a) Be in BeCl2 (b) B in BCl3 (c) H in H2O ?
  
• How to figure out whether a bond is more ionic than covalent?
  
• How to find the indefinite integral of #sin(2x)cos(2x)dx#?
  
• An object falls a distance h from rest. If it travels .50h in the last 1.00s, find (a) the time and (b) the height of its fall?
  
• (9.38) x (53201) = 499025.4 What is the answer express to the correct number of significant figures?
  
• Cos(38.1) = 0.7869350 What is the answer expressed to the correct number of significant figures. How do you know what the significant figures here?
  
• Only two horizontal forces act on a 3.0 kg body that can move over a frictionless floor. One force is 9.0 N, acting due east, and the other is 8.0 N, acting 62 degree north of west. What is the magnitude of the body's acceleration?