Chemistry concepts and calculations
117302 questions • Page 248 / 2347
20. Consider the following half-reactions at 298 K: + 2e- Fe Eored=-0.441 V Cd2+
20. Consider the following half-reactions at 298 K: + 2e- Fe Eored=-0.441 V Cd2++ Cd Eed-0.403 v A galvanic cell based on these haif-reactions is set up under standard conditions …
20. Consider the reaction: C + o, -co, AH-393 kJ How many grams of carbon must b
20. Consider the reaction: C + o, -co, AH-393 kJ How many grams of carbon must be burned to release 275 kJ of heat? a. 22.3 g b. 8.4g c. 12.0g d. 17.1g 21. Given the following: Fi…
20. Determine the oxidation number of the underlined element in H 2 P 2 O 7 . a.
20. Determine the oxidation number of the underlined element in H2P2O7. a. +6 b. +7 c. +3 d. +4 e. +5 21. Which statement is false? a. Ordinary chemical …
20. Determine the oxidation number of the underlined element in H 2 P 2 O 7 . a.
20. Determine the oxidation number of the underlined element in H2P2O7. a. +6 b. +7 c. +3 d. +4 e. +5 21. Which statement is false? a. Ordinary chemical …
20. If the equilibrium shown below is heated at a constant pressure. H2(g) +12(g
20. If the equilibrium shown below is heated at a constant pressure. H2(g) +12(g)2HI(g) +65 kJ What is most likely to happen? a. Keq gets larger b. Keq gets smaller. c. [Hal gets …
20. If the equilibrium shown below is heated at a constant pressure. H2(g) +12(g
20. If the equilibrium shown below is heated at a constant pressure. H2(g) +12(g)2HI(g) +65 kJ What is most likely to happen? a. Keq gets larger b. Keq gets smaller. c. [Hal gets …
20. In a chemical reaction, dynamic equilibrium occurs when the rate of the forw
20. In a chemical reaction, dynamic equilibrium occurs when the rate of the forward reaction becomes precisely equal to the rate of the reverse reaction. All of the following stat…
20. In most proteins this amino acid\'s side chain is found clustered away from
20. In most proteins this amino acid's side chain is found clustered away from the aqueous exterior of the protein as a result of which interaction? a) Hydrophobic effect b) Charg…
20. In the circuit at the right the switch S is switched to position a for 2 hou
20. In the circuit at the right the switch S is switched to position a for 2 hours, then switched to position b. a. 12 seconds after being switched to position T 2M2 b, what is th…
20. Methane and hydrogen sulfide react to produce carbon disulfide and hydrogen
20. Methane and hydrogen sulfide react to produce carbon disulfide and hydrogen according to the following equation: If 8.00 mol of CS2(g) and 20.0 moI of H2(g) are placed in a 4.…
20. Methanol (CH3OH) is produced commercially by the catalyzed reaction of carbo
20. Methanol (CH3OH) is produced commercially by the catalyzed reaction of carbon monoxide and hydrogen: CO(g)+2H2(g)CH3OH(g). An equilibrium mixture in a 2.50L vessel is found to…
20. Predict the sign of S of the system for each of the following reactions. (1)
20. Predict the sign of S of the system for each of the following reactions. (1) 2A(s) + B2(g) 2AB(g) (2) X4Y10(g) X4Y10(l) A. S is zero for both reactions. B. S is negative for b…
20. Sodium cyclamate, CaH NHS0,Na, was usedat one time as an artificial sweetner
20. Sodium cyclamate, CaH NHS0,Na, was usedat one time as an artificial sweetner. If CH,NHSOMa has a molecular mass of 201.2 g/mol. how many moles of sodium cyclamate are containe…
20. The ?Hfº of MgO is –602 kJ•mol?1. When 20.15 g MgO is decomposed at constant
20. The ?Hfº of MgO is –602 kJ•mol?1. When 20.15 g MgO is decomposed at constant pressure according to the equation below, how much heat will be transferred? 2 MgO(s) -> 2 Mg(s…
20. The Km is a. The time for half of the substrate to be converted to product b
20. The Km is a. The time for half of the substrate to be converted to product b. The time for all of the substrate to be converted to product C. The [S] that gives half of the ma…
20. The decomposition of dinitrogen pentoxide has the rate law: If the initial c
20. The decomposition of dinitrogen pentoxide has the rate law: If the initial concentration rate- 0.080 min [N20s] of N2Os is 0.30 M, what is the concentration after 2.6 minutes?…
20. The electron in a hydrogen atom, originally in level n-9, undergoes a transi
20. The electron in a hydrogen atom, originally in level n-9, undergoes a transition to a lower level by cmiting a photon of wavelength 384 nm. What is the final level ofthe elect…
20. The esterification of the carbon three position of diacylglycerol requires a
20. The esterification of the carbon three position of diacylglycerol requires acyl transferase which forms triacylglycerol (triglyceride). True or False 21. Which of the followin…
20. The following reaction: 4 Al + 3 O2 ? 2 A120, is an example of A. combinatio
20. The following reaction: 4 Al + 3 O2 ? 2 A120, is an example of A. combination. B. decomposition. C. single-displacement D. double-displacement. . The reaction: CH4+202 A. endo…
20. The following thermodynamic data at 25°C have been tabu- lated for the gas-p
20. The following thermodynamic data at 25°C have been tabu- lated for the gas-phase reaction shown as follows (dotted lines represent hydrogen bonds): O...H-O 2 H-C C-H O-H HCOOH…
20. The following thermodynamic data at 25°C have been tabu- lated for the gas-p
20. The following thermodynamic data at 25°C have been tabu- lated for the gas-phase reaction shown as follows (dotted lines represent hydrogen bonds): O...H-O 2 H-C C-H O-H HCOOH…
20. The mass of a vessel filled with dry air is 97.432 g. Then, an unknown gas s
20. The mass of a vessel filled with dry air is 97.432 g. Then, an unknown gas sample was injected into this vessel. The resulting mass of the vessel is 99.420 g. When this same v…
20. The value of A f or an atom containing 12 protons, 12 electrons a. 24 b. 4 c
20. The value of A f or an atom containing 12 protons, 12 electrons a. 24 b. 4 c. 28 d. 12 e. 16 21. Which group of elements contains only non-metals? a. C, Si,F b. O, Br, Xe c. A…
20. These minerals are found as ions in food sources 21. Adding salt solution in
20. These minerals are found as ions in food sources 21. Adding salt solution in the milk to obtain calcium phosphate, Precipitation, A suction filtration process Give a possible …
20. What is the change in entropy at 298 K of the surroundings if a reaction is
20. What is the change in entropy at 298 K of the surroundings if a reaction is 150 kJ exothermie? a)+839 J/K b)+4.47 X 107 J/K c) +1.98 J/K d)+503 J/K e)+1,170 J/K 21. How many e…
20. What is the hydroxide ion concentration of an aqueous0.00353 M caffeine solu
20. What is the hydroxide ion concentration of an aqueous0.00353 M caffeine solution? The most basic nitrogen atom incaffeine has a Kb of 4.1 x10-4. 21. Amonoprotic acid has a ka …
20. What is the mole fraction of hydrogen in a gaseous mixture that consists of
20. What is the mole fraction of hydrogen in a gaseous mixture that consists of 8.00 g of hydrogen and 12.00 g of neon in a 3.50 liter container maintained at 35.20 "C? a. 0.150 b…
20. What is the output of the following code? int s = 1, n = 1; while (s < 10) {
20. What is the output of the following code? int s = 1, n = 1; while (s < 10) { } ++n; s += n; cout << s << ' '; a.2 4 7 11 d. 3 6 9 b.3 6 10 e. 1 2 3 4 5 6 7 8 9 …
20. When atoms of an element are emitting a certain wavelength (or color) of lig
20. When atoms of an element are emitting a certain wavelength (or color) of lig a) the atoms have gained energy and electrons have jumped to an b) the atoms have gained energy an…
20. Which choice best indicates the degree of correctness of this statement? \"A
20. Which choice best indicates the degree of correctness of this statement? "At standard pressure the boiling point of normal propanol is higher than the boiling point of water."…
20. Which choice best indicates the degree of correctness of this statement? \"I
20. Which choice best indicates the degree of correctness of this statement? "If two open vessels, one containing normal propanol and the other containing water, both at the same …
20. Which is not the atomic number of an alkali metal: a. 87 b. 37 c. 55 d. 73 2
20. Which is not the atomic number of an alkali metal: a. 87 b. 37 c. 55 d. 73 21. Which group(s) combines with an halogen to form a salt a. b. I d. IV 22. The element in Period 3…
20. Which is not the atomic number of an alkali metal: a. 87 b. 37 c. 55 d. 73 2
20. Which is not the atomic number of an alkali metal: a. 87 b. 37 c. 55 d. 73 21. Which group(s) combines with an halogen to form a salt a. b. I d. IV 22. The element in Period 3…
20. Which of the following increases the affinity of hemoglobin for oxygen? A. a
20. Which of the following increases the affinity of hemoglobin for oxygen? A. an increase in BPG concentration. B. the formation of N-terminal carbamates. C. raising pH. D. Oxyge…
20. Which of the following is NOT correct concerning 2,3-bisphosphoglycerate (BP
20. Which of the following is NOT correct concerning 2,3-bisphosphoglycerate (BPG)? A It increases the affinity of hemoglobin for oxygen. B. It binds at a distance from the heme g…
20. Which of the following is a conjugated diene (A) 2-methylcyclohexanone (D) c
20. Which of the following is a conjugated diene (A) 2-methylcyclohexanone (D) cyclohexa-1,4-diene (B) cyclohexa-1,3-diene (E) cycloocta-1,5-diene (C) 1-methylcyclohexa-1,4-diene …
20. Which of the following material s would show the smallest temperature change
20. Which of the following material s would show the smallest temperature change upon gaining 200.0 J of heat? a. 50.0 grams water (specific heat capacity of water 4.184mg b. 50.0…
20. Which of the following processes would be accompanied by a decrease in entro
20. Which of the following processes would be accompanied by a decrease in entropy B) HO)H:O(B) E H:O(l, 50°C)-H.00, 75°C) 21. Determine os" for the reaction soog) +1 100) ? HS00)…
20. Which reaction is faster and why? HO A CH,CH,CHO Gerun A, because F is a bet
20. Which reaction is faster and why? HO A CH,CH,CHO Gerun A, because F is a better leaving group that I b. ) B, because I is a better leaving group that F A, because F stabilizes…
20. Which statement below regarding vapor pressure is not correct? a. Vapor pres
20. Which statement below regarding vapor pressure is not correct? a. Vapor pressure is an intensive property. b. The substance with the stronger intermolecular forces has the low…
20. Which substitution mechanism is not used in any of the syntheses of question
20. Which substitution mechanism is not used in any of the syntheses of questions 17.-19.? 17.-19. Starting with benzene, complete the following reaction sequences. Assume any nec…
20. compound with molar mass 180.2 g/mol has the following composition: Determin
20. compound with molar mass 180.2 g/mol has the following composition: Determine the molecular formula (Express your answer as a chemical formula.) (Input the elements in your fo…
20. what do the following terms mean? a. monomer b. polymer 26. what is the effe
20. what do the following terms mean? a. monomer b. polymer 26. what is the effect of vulcanization process? 28. by using polyethylene as an exampmle draw a portion of a. a linear…
20.0 g each of Fe2O3 and AI are mixed together and react according to the follow
20.0 g each of Fe2O3 and AI are mixed together and react according to the following equation. What is the theoretical yield of Fe? Report your answer in grams, to three significan…
20.0 g of an unknown gas is combined with helium in a 1500. mL container at 25 d
20.0 g of an unknown gas is combined with helium in a 1500. mL container at 25 degree C giving a total pressure of 86.110 atm. Given that the partial pressure of helium is 81.513 …
20.0 mL of a .500 M solution of hydrofluoric acid is titrated with .200 M NaOH t
20.0 mL of a .500 M solution of hydrofluoric acid is titrated with .200 M NaOH to the equivalence point. The Ka of HF is 7.2x-4 (1)What volume of NaOH will be needed to completely…
20.0 mL of aqueous solution of 0.0500mol/L barium hydroxide is titrated with 0.1
20.0 mL of aqueous solution of 0.0500mol/L barium hydroxide is titrated with 0.100mol/L of hydroiodic acid. Calculate the number of moles of all ions in the erlenmeyer after 5.50m…
20.00 mL of an unknown concentration of Acetate (C2H3O2-) is titrated to its equ
20.00 mL of an unknown concentration of Acetate (C2H3O2-) is titrated to its equivalence point with 20.00 mL of 0.100 M HCl. The pka of acetic acid = 4.76. Draw a titration curve …
20.01 6) Compare the change in pll that occurs when added to 100 ml of a benzoic
20.01 6) Compare the change in pll that occurs when added to 100 ml of a benzoic results. of s benzoiec acid buffer solutionhat is 0.15 M in both C,H,co,H and C,H,CO Na. Explain t…
20.0ml of 0. 100M HCI solution in a small beaker is titrated with 0.10M NaOH sol
20.0ml of 0. 100M HCI solution in a small beaker is titrated with 0.10M NaOH solution from a buret. All experiments are carried out at 25°C 2. a) Write the acid-base reaction that…
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