Chemistry concepts and calculations
117302 questions • Page 1993 / 2347
When NaHCO_3 is heated above 270 Degree C, it decomposes to Na2C03, H2O, and CO2
When NaHCO_3 is heated above 270 Degree C, it decomposes to Na2C03, H2O, and CO2. Write a balanced chemical equation for the decomposition reaction. Do not include phases. Calcula…
When NaHCO_3 is heated above 270 degree C, it decomposes to Na_2CO_3, H_2O, and
When NaHCO_3 is heated above 270 degree C, it decomposes to Na_2CO_3, H_2O, and CO_2. Write a balanced chemical equation for the decomposition reaction. Do not include phases. Cal…
When Nitrogen from a gaseous phase is to be diffused into pure iron, the Do and
When Nitrogen from a gaseous phase is to be diffused into pure iron, the Do and Qa are 5.0 x 10 77,000 , respectively. It is assumed that the initial concentration of Nis0wt% N. D…
When Synthesis and characterization of HA and CHA Why are the carbonate and phos
When Synthesis and characterization of HA and CHA Why are the carbonate and phosphate sources mixed together before adding to the calcium solution? What would happen if you were t…
When Thomas Edison first sold electricity, he used zinc coulometers to measure c
When Thomas Edison first sold electricity, he used zinc coulometers to measure charge consumption. (In a coulometer the cathode is weighed before a current is passed through it, a…
When User A decides he want to pay a visit to http://example.com/ it all begins
When User A decides he want to pay a visit to http://example.com/ it all begins with a Request. A short moment later he is given a Response. In this cycle Request-Response a lot i…
When What is the molecular formula of the precipitate? AgNO3 23.54 mL of 0.342 M
When What is the molecular formula of the precipitate? AgNO3 23.54 mL of 0.342 M silver nitrate is combined with 18.61 mL of 0.867 M potassium chloride, a precipitate forms. Submi…
When ^4He is cooled below 2.17 K it becomes a \"superfluid\" with unique propert
When ^4He is cooled below 2.17 K it becomes a "superfluid" with unique properties such as the viscosity approaching zero. One way to learn about the superfluid environment is to m…
When _____ of propane (C 3 H 8 ) gas isburned in excess oxygen, following the eq
When _____ of propane (C3H8) gas isburned in excess oxygen, following the equation below,____kJ ofheat is evolved. C3H8 (g) + 5O2 (g) --->3CO2 (g) + 4H2O ( l ) How much water (…
When _____ of propane (C 3 H 8 0 gas isburned in excess oxygen, following the eq
When _____ of propane (C3H80 gas isburned in excess oxygen, following the equation below,____kJ ofheat is evolved. C3H8 (g) + 5O2 (g) --->3CO2 (g) + 4H2O ( l ) How much water (…
When a 0.3167 gram sample of an unknown compound, (containing only carbon, hydro
When a 0.3167 gram sample of an unknown compound, (containing only carbon, hydrogen and nitrogen), is burned, 0.7733 gram of carbon dioxide and 0.2109 gram of water are produced. …
When a 0.6333-g sample of a compound of carbon, hydrogen and sulfur was burned i
When a 0.6333-g sample of a compound of carbon, hydrogen and sulfur was burned in excess oxygen, 0.9272 g CO2, 0.3795 g H2O and 0.6749 g SO2 were obtained. In a separate experimen…
When a 10.03 g sample of ethanol, C_2H_5OH_1 is burned in a calorimeter whose he
When a 10.03 g sample of ethanol, C_2H_5OH_1 is burned in a calorimeter whose heat capacity is 42.2 kJ/degree C, the calorimeter heated up from 15.0 degree C to 43.1 degree C. Use…
When a 13.62 mL volume of vinegar is used in a titration, it is found that 27.93
When a 13.62 mL volume of vinegar is used in a titration, it is found that 27.93 mL of 0.150 M NaOH is needed to reach the equivalence point. A. Calculate the moles of NaOH added …
When a 235 92U nucleus is bombarded by neutrons (10n) it undergoes a fission rea
When a 235 92U nucleus is bombarded by neutrons (10n) it undergoes a fission reaction, resulting in the formation of two new nuclei and neutrons. The following equation is an exam…
When a 235 92U nucleus is bombarded by neutrons (10n) it undergoes a fission rea
When a 235 92U nucleus is bombarded by neutrons (10n) it undergoes a fission reaction, resulting in the formation of two new nuclei and neutrons. The following equation is an exam…
When a 24.0 g of a metal sample is heated in water at 100.0degreeC, then transfo
When a 24.0 g of a metal sample is heated in water at 100.0degreeC, then transformed into 50.0 g sample of liquid water at 25.0 C in a coffee-cup calorimeter, the final temperatur…
When a 27.2 mL sample of a 0.371 M aqueous hydrocyanic acid solution is titrated
When a 27.2 mL sample of a 0.371 M aqueous hydrocyanic acid solution is titrated with a 0.316 M aqueous potassium hydroxide solution, what is the pH at the midpoint in the titrati…
When a 3.76-g sample of solid iron(III) chloride dissolves in 47.9 g of water in
When a 3.76-g sample of solid iron(III) chloride dissolves in 47.9 g of water in a coffee-cup calorimeter (see above figure) the temperature rises from 24.00 oC to 40.03 oC. Calcu…
When a 4.348 g sample of NaOH(s) is dissolved in 100 g of water in a calorimeter
When a 4.348 g sample of NaOH(s) is dissolved in 100 g of water in a calorimeter, the temperature rises from 23.6 oC to 47.4 oC. Calculate Hdiss in kJ/mol. Assume that Ccalorimete…
When a 4.348 g sample of NaOH(s) is dissolved in 100 g of water in a calorimeter
When a 4.348 g sample of NaOH(s) is dissolved in 100 g of water in a calorimeter, the temperature rises from 23.6 °C to 47.4 °C. Calculate AHdiss in kJ/mol. Assume that Ccalorimet…
When a 9.00 g sample of metal is heated to 100.0 C, anddropped into 20.0 mLs of
When a 9.00 g sample of metal is heated to 100.0 C, anddropped into 20.0 mLs of water at 25.00 C, the final temperature is28.9 C. a.) calculate the specific heat of the metal, ass…
When a K shell electron in a Tungsten atom is replaced by a M shell electron fro
When a K shell electron in a Tungsten atom is replaced by a M shell electron from the same atom, a radiation photon with energy is released. a. 69 B. 66 C. 8 D. 75 30. Lead (Pb) h…
When a beta particle penetrates a material, it wil keep corusing until its kinet
When a beta particle penetrates a material, it wil keep corusing until its kinetic energy is totally spent. The depth of penetration depends on the speed of the particle when it e…
When a beta-particle (an energetic electron emitted from the nucleus of a radioa
When a beta-particle (an energetic electron emitted from the nucleus of a radioactive material) penetrates a material, it will keep coursing until its kinetic energy is totally sp…
When a carbon is attached to four different atoms or groups of atoms, the shape
When a carbon is attached to four different atoms or groups of atoms, the shape of the carbon is tetrahedral. A tetrahedral structure is a three-dimensional structure and is not e…
When a catalyst is added to a reaction mixture a. The reaction rate decrease b.
When a catalyst is added to a reaction mixture a. The reaction rate decrease b. Activation energy of the reaction decrease c. Activation energy of the reaction increase d. The sig…
When a chemical is manufactured, chemists and chemical engineers choose conditio
When a chemical is manufactured, chemists and chemical engineers choose conditions that will favor the production of the desired product as much as possible. In the early 20^th ce…
When a chemical reaction is at equilibrium, Q (the reaction quotient) is equal t
When a chemical reaction is at equilibrium, Q (the reaction quotient) is equal to K (the equilibrium constant). If a stress is applied to the mixture that changes the value of Q, …
When a chemical reaction is at equilibrium, Q (the reaction quotient) is equal t
When a chemical reaction is at equilibrium, Q (the reaction quotient) is equal to K (the equilibrium constant). If a stress is applied to the mixture that changes the value of Q, …
When a chemical reaction is at equilibrium, Q (the reaction quotient) is equal t
When a chemical reaction is at equilibrium, Q (the reaction quotient) is equal to K (the equilibrium constant). If a stress is applied to the mixture that changes the value of Q, …
When a chemical reaction is at equilibrium, Q (the reaction quotient) is equal t
When a chemical reaction is at equilibrium, Q (the reaction quotient) is equal to K (the equilibrium constant). If a stress is applied to the mixture that changes the value of Q, …
When a chemical reaction is run in aqueous solution inside a calorimeter, the te
When a chemical reaction is run in aqueous solution inside a calorimeter, the temperature change of the water (and Ccal) can be used to calculate the enthalpy change for the react…
When a chemist mixed 3.33 g of LiOH and 255 mL of 0.62 M HCl in a constant-press
When a chemist mixed 3.33 g of LiOH and 255 mL of 0.62 M HCl in a constant-pressure calorimeter, the final temperature of the mixture was 23.4°C. Both the HCl and LiOH had the sam…
When a chemist mixed 3.60 g of LiOH and 180. mL of 0.65 M HCl in a constant-pres
When a chemist mixed 3.60 g of LiOH and 180. mL of 0.65 M HCl in a constant-pressure calorimeter, the final temperature of the mixture was 25.4°C. Both the HCl and LiOH had the sa…
When a chemist mixed 3.61 g of LiOH and 170. mL of 0.68 M HCl in a constant-pres
When a chemist mixed 3.61 g of LiOH and 170. mL of 0.68 M HCl in a constant-pressure calorimeter, the final temperature of the mixture was 25.3°C. Both the HCl and LiOH had the sa…
When a chemist speaks of an equilibrium, what does he or she mean? Specifically,
When a chemist speaks of an equilibrium, what does he or she mean? Specifically, what is equal in an equilibrium? A mountain river flows into a lake. The level of the lake varies …
When a clean iron nail is placed in an aqueous solution of copper(II) sulfate, t
When a clean iron nail is placed in an aqueous solution of copper(II) sulfate, the nail becomes coated with a brownish black material. What is the name of the material coating the…
When a commercial drain cleaner that contains sodium hydroxide and small pieces
When a commercial drain cleaner that contains sodium hydroxide and small pieces of aluminum is poured into a clogged drain, the following reaction occurs: Al + NaOH + H_2O rightar…
When a compound containing C and H is burned in oxygen, the reaction produces 0.
When a compound containing C and H is burned in oxygen, the reaction produces 0.90 mol of CO2 and 0.45 mol of H2O. Determine the number of moles of carbon in the compound. Express…
When a concentration of substrates increases continuously in a simple chemical r
When a concentration of substrates increases continuously in a simple chemical reaction, the rate of product formation continues increasing. Is t also the case for an enzymatic re…
When a corpse decomposes, much of the phosphorus in the body is converted to pho
When a corpse decomposes, much of the phosphorus in the body is converted to phosphine (PH3), a colourless gas with the odour of rotting fish. Phosphorus is a highly reactive mole…
When a credit card is scanned, a sequence of 8-bit codes appears on the scanner’
When a credit card is scanned, a sequence of 8-bit codes appears on the scanner’s data output lines (SCAN_DATA8-1). Each byte is held on these lines for about 1 microsecond; when …
When a current is passed through a sulfuric acid solution, water is electrolyzed
When a current is passed through a sulfuric acid solution, water is electrolyzed. The half reactions that occur are: Use the diagram below to: indicate which half-reaction occurs …
When a disulfide linkage is formed, the compound containing this new linkage has
When a disulfide linkage is formed, the compound containing this new linkage has been hydrolyzed. dehydrated. electrolyzed. oxidized. reduced In conventional peptide synthesis, th…
When a few drops of sodium fluoride solution are added to a solution containing
When a few drops of sodium fluoride solution are added to a solution containing iron (III) ions a colourless solution is obtained. Fe3+(aq) + 6 F-(aq) FeF63-(aq) Pale yellow colou…
When a firecracker explodes, giving off light and heat andbreaking the wrapper i
When a firecracker explodes, giving off light and heat andbreaking the wrapper into many pieces, A. a physical change takes place B. a chemical change takes place C. both A & …
When a flammable liquid such as gasoline ignites, the substance actually burning
When a flammable liquid such as gasoline ignites, the substance actually burning is vapor that is generated from the liquid. If the concentration of the vapor in the air about the…
When a folded protein in solution is heated to a high enough temperature, its po
When a folded protein in solution is heated to a high enough temperature, its polypeptide chain will unfold to become the "denatured protein"- a process known as denaturation. The…
When a fraudulent credit card CNP (Card Not Present) transaction is made, mercha
When a fraudulent credit card CNP (Card Not Present) transaction is made, merchant is liable for the chargeback. For that reason, our company implemented a policy where we ask a p…
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