Description The combustion of 135 mg of a hydrocarbon produces 440mg of co2 and 135 mg H20. The molar mass of the...? hydrocarbon is 270 g/mol. Determine the molecular formula of this compound.
Description As density is an intensive property, it is very useful for identification purposes. Density is also a valuable unit convrsion for converting volume to mass or mass to volume. the density of ethanol at 20 c is 0.789g/mL. a) calculate the mass of 25.mL of ethanl. b)Suggest a situation where weighing may be preferable to a volume measurement. c) Calculate the volume of 25.0g of ethanhol. d) Suggst a situation where a volume measurement may be preferable to weighing.
Description Data for the decomposition of hydrogen peroxide at some set temperature T is provided below. The rate law depends only on the concentration of H2O2. 2 H2O2 ---> 2 H2O + O2 t (seconds) 0 60 120 180 240 360 420 600 [H2O2] (M) 0.882 0.697 0.566 0.458 0.372 0.236 0.188 0.094 1) What is the value of the rate constant, k? 2) What is the half life of the reaction when the initial concentration of H2O2 is 0.882 M? 3) What is the average rate of reaction, R, from t = 60 to t = 120?
Description Question 10 A rise in temperature or pressure of a monomer, increasing the risk of the container vessel rupturing is ___________ Question 8 The substance produced by the condensation of a glycol and an organic di¬isocyanate is called __________ Question 7 The phenomenon associated with the spread of fire from a burning area to other areas physically isolated from the initial fire source is known as __________ Question 6 Hydrogen cyanide is formed from the combustion of polyurethane and may pose an inhalation hazard. One study of polyurethane combustion indicated that the maximum yield of hydrogen cyanide per gram of polyurethane foam ranged from 0.5 to 1.05 milligrams under flaming conditions. Using this study, what is the possible maximum milligrams of hydrogen cyanide that is formed when 5 kilograms of polyurethane foam is burned during a fire incident? __________ Question 5 When nitric acid is added to cellulose, a chemical reaction occurs, during which the cellulose is converted into: nitrocellulose. paper. polyester. acrylics.
Description the specific heat of copper is 0.093 cal/g degree celcius and the specific heat of silver is 0.057 cal/g degree celcius. If 200 cal of heat is added to one g of each metal at 25 degree celcius. which one of them will have higher temperature
Description Question 5 An old cooling tower is being demolished at a gas processing plant. Which of the following statements would be FALSE? Cr+6 can be found in the cooling tower debris. Workers could be exposed to Cr+6 during demolition if not wearing the appropriate PPE. Cr+6 will unlikely be found in subsurface soil. Exposure to Cr+6 can be by inhalation or ingestion. Question 6 Shipping bales of unprocessed cotton alongside a boxcar containing concentrated perchloric acid is potentially hazardous since 60 to 72.5% perchloric acid is an NFPA __________ oxidizer that causes a severe increase in the burning rate of the cotton. Question 7 The tarnishing of silver is an example of a __________ reaction. Question 8 The components of ordinary gunpowder are elemental sulfur, charcoal, and potassium nitrate. When gunpowder explodes, these components react as follows: 3S8(s) + 16C(s) + 32KNO3(s) Sulfur Carbon Potassium nitrate 16K2O(s) + 16CO2(g) + 16N2(g) + 24SO2(g) Potassium oxide Carbon dioxide Nitrogen Sulfur dioxide For this redox reaction, the reducing agents are __________ and __________.4 points Question 9 A dilute solution of __________ is effective in treating athlete’s foot because of its oxidizing capabilities. Question 10 Following Hurricane Katrina in 2005, what oxidizer did cleanup crews use to eradicate the mold that grew in homes __________?
Description quark - C atom - He atom - neutrino (e, muon, tau), e, tau, proton, neutron, nucleus, muon, H atom, O atom, CO2 molecule, H2O molecule, cellulose, buckyball, carbon nonotube, graphene sheet, piece of coal
Description QUESTION 1 Properties of a solution that depend only on the ratio of the number of particles of solute and solvent in the solution are known as __________. intensive properties physical properties colligative properties chemical properties 3 points QUESTION 2 How does adding a non-volatile solute to a pure solvent affect the vapor pressure of the pure solvent? The solution will have a lower vapor pressure than the pure solvent. The solution will have a higher vapor pressure than the pure solvent. The solvent’s vapor pressure will not be affected. The solvent’s vapor pressure will most likely change, but not in a predictable way. 3 points QUESTION 3 To melt the ice on your driveway, you can use 2 moles of rock salt (NaCl) or 2 moles of calcium chloride (CaCl2). Which solute will have the greatest effect and why? NaCl because it is completely soluble in water NaCl because it produces fewer moles of solute particles per mole of compound CaCl2 because it produces more moles of solute particles per mole of compound CaCl2 because it is less volatile than NaCl 3 points QUESTION 4 What is the molality of a solution that contains 1.50 moles of NaOH in 250 mL of water? (The density of water is equal to 1.0 .) 6.0 m 0.006 m 0.375 m 375 m 3 points QUESTION 5 A 300 gram sample of pure water exerts a vapor pressure of 750 millimeters of mercury on the walls of its container. If 0.27 moles of glucose (C6H12O6) is added to the water, what will be the vapor pressure of the resulting solution? 0.98 mm Hg 12 mm Hg 740 mm Hg 750 mm Hg 3 points QUESTION 6 What would be the freezing point of a 1.7 molal aqueous ethylene glycol (C2H6O2) solution? The freezing point depression constant for water = 1.86°C/m. 3.2°C –1.1°C 0.0°C –3.2°C 3 points QUESTION 7 What would be the boiling point of a 3.4 molal aqueous glucose (C6H12O6) solution? The boiling point elevation constant for water = 0.512°C/m. 1.7°C 6.64°C 98.3°C 101.7°C 3 points QUESTION 8 Which of the following properties of pure solvents decrease when a solute is added? boiling point vapor pressure freezing point volume
Description the exact quantities of the reactants and products information about how fast the reaction will proceed ratios of atoms, ions, molecules and/or formula units used in the equation an outline of how the substances change from reactants to products
