Chemistry concepts and calculations

1. A benzene ring with activating substitutents can be considered a a. electroph

1. A benzene ring with activating substitutents can be considered a a. electrophile b. nucleophile c. inert compound 2. What gas is produced when bromine ion complex reacts with t…

1. A bird stands on an electric transmission line carrying 2360A, as seen in the

1. A bird stands on an electric transmission line carrying 2360A, as seen in the figure below. The line has 2.60×10-5Ohm resistance per meter and the bird's feet are 4.40cm apart.…

1. A bomb calorimeter , or a constant volume calorimeter, is a device often used

1. A bomb calorimeter, or a constant volume calorimeter, is a device often used to determine the heat of combustion of fuels and the energy content of foods. In an experiment, a 0…

1. A bomb calorimeter , or constant volume calorimeter, is a device often used t

1. A bomb calorimeter, or constant volume calorimeter, is a device often used to determine the heat of combustion of fuels and the energy content of foods. Since the "bomb" itself…

1. A bomb calorimeter , or constant volume calorimeter, is a device often used t

1. A bomb calorimeter, or constant volume calorimeter, is a device often used to determine the heat of combustion of fuels and the energy content of foods. Since the "bomb" itself…

1. A bottle of inexpensive white wine has a pH of 2.85. a) What color will the i

1. A bottle of inexpensive white wine has a pH of 2.85. a) What color will the indicator phenolphthalein display when added to the white wine? b) What is the hydronium ion concent…

1. A bowl of 464 g of water is placed in a microwave oven that puts out 776 watt

1. A bowl of 464 g of water is placed in a microwave oven that puts out 776 watts (J/s). How long would it take in seconds to increase the temperature of the water from 12.0oC to …

1. A box contains a mixture of small copper spheres and small lead spheres. The

1. A box contains a mixture of small copper spheres and small lead spheres. The total volume of both metals is measured by the displacement of water to be 430 cm3 and the total ma…

1. A box contains a mixture of small copper spheres and small lead spheres. The

1. A box contains a mixture of small copper spheres and small lead spheres. The total volume of both metals is measured by the displacement of water to be 430 cm3 and the total ma…

1. A box of salt contains 1668 grams of sodium chloride. How many moles of sodiu

1. A box of salt contains 1668 grams of sodium chloride. How many moles of sodium are present? Make sure to include the correct unit symbol with the answer choice. 2. At STP, what…

1. A buffer contains significant amounts of ammonia and ammonium chloride. A). W

1. A buffer contains significant amounts of ammonia and ammonium chloride. A). Write an equation showing how this buffer neutralizes added acid (HNO3). Express your answer as a ch…

1. A buffer is composed of .4 mole H2PO4- and 0.4mol HPO4^2- diluted with water

1. A buffer is composed of .4 mole H2PO4- and 0.4mol HPO4^2- diluted with water to a volume of 1.0L. The ph of the buffer is 7.210. How many miles of HCL must be added to decrease…

1. A buffer is composed of .4 mole H2PO4- and 0.4mol HPO4^2- diluted with water

1. A buffer is composed of .4 mole H2PO4- and 0.4mol HPO4^2- diluted with water to a volume of 1.0L. The ph of the buffer is 7.210. How many miles of HCL must be added to decrease…

1. A buffer is made by mixing 1.250 mol formic acid, HCOOH, with 0.750 mol sodiu

1. A buffer is made by mixing 1.250 mol formic acid, HCOOH, with 0.750 mol sodium formate, HCOONa in enough water for a total volume of 1.00L. The Ka of formic acid is 1.87 x 10-4…

1. A buffer solution consists of 0.25 M acetic acid (CH3COOH) and 0.10 M sodium

1. A buffer solution consists of 0.25 M acetic acid (CH3COOH) and 0.10 M sodium acetate (CH3COONa). The Ka of acetic acid is 1.8×105. a. Calculate the equilibrium pH using the equ…

1. A buffer solution contains 0.408 M ammonium bromide and 0.313 M ammonia . If

1. A buffer solution contains 0.408 M ammonium bromide and 0.313 M ammonia. If 0.0353 moles of sodium hydroxide are added to 225 mL of this buffer, what is the pH of the resulting…

1. A buffer solution contains 0.458 M Na HCO 3 and 0.328 M K 2 CO 3 . Determine

1. A buffer solution contains 0.458 M NaHCO3 and 0.328 M K2CO3. Determine the pH change when 0.083 mol HNO3 is added to 1.00 L of the buffer. pH change = 2. Determine the pH chang…

1. A buffer solution is prepared by mixing 50.0 mL of 0.300 M NH3 with 50.0 mL o

1. A buffer solution is prepared by mixing 50.0 mL of 0.300 M NH3 with 50.0 mL of 0.300 M Nh4cl. the pKb of NH3 is 4.74 NH3 +H2O --> NH4+ + OH- a. Calculate the [NH3} and [NH4C…

1. A buffer solution was prepared in 100 mL volumetric flask by mixing 15 mL of

1. A buffer solution was prepared in 100 mL volumetric flask by mixing 15 mL of 0.30 M acetic acid (a weak acid) with 15 mL of 0.30 M sodium acetate (a salt of the weak acid) and …

1. A buffer with a pH of 4.51 is made from acetic acid/acetate ion conjugate pai

1. A buffer with a pH of 4.51 is made from acetic acid/acetate ion conjugate pair. Which of these solutions will give the correct buffer pH AND have the greatest buffer capacity? …

1. A bufter system a consists of a strong acid and a strong base. b. can never l

1. A bufter system a consists of a strong acid and a strong base. b. can never lose its buffering capability e can maintain a fairly constant pil over a narrow range. d is none of…

1. A burglary has occurred in single story house and you are tasked to search fo

1. A burglary has occurred in single story house and you are tasked to search for potential latent impression evidence. List five (5) particular items that would contain latent fi…

1. A cell where electricty is used to make the reactions run in a nonspontaneous

1. A cell where electricty is used to make the reactions run in a nonspontaneous direction is a__ cell. A) Avogadro B) Electrolytic C) Galvanic D) Voltaic 2. Alkaline batteries us…

1. A certain natural product having [?] D + 40.3° was isolated. Two structures h

1. A certain natural product having [?]D + 40.3° was isolated. Two structures have been independently proposed for this compound. Which one do you think is more likely to be corre…

1. A certain reaction has an activation energy of 54.0 kJ/mol. As the temperatur

1. A certain reaction has an activation energy of 54.0 kJ/mol. As the temperature is increased fromm 22 degree C to a higher temperature, the rate constant increases by a factor o…

1. A certain solution has a concentration of 1.0 x 10 - 4 M of OH - . Which of t

1. A certain solution has a concentration of 1.0 x 10-4 M of OH-. Which of the following statements is true? Select one: A. The solution has a pH of 10. B. The solution is acidic.…

1. A certain weak acid, HA, has a K a value of 9.6x10 -7 . Calculate the percent

1. A certain weak acid, HA, has a Ka value of 9.6x10-7. Calculate the percent ionization of HA in a 0.10 M solution. 2. Acetic acid, CH3CO2H, is the solute that gives vinegar its …

1. A chemical reaction has just occurred in an insulated isolated system which c

1. A chemical reaction has just occurred in an insulated isolated system which caused an overall increase in the potential energy of the system. Which statement below is true? a. …

1. A chemical reaction is observed to convert Molecule A into Molecule B. The ac

1. A chemical reaction is observed to convert Molecule A into Molecule B. The accompanying graph plots the change in concentration for both molecules against the change in time. U…

1. A chemist adds 0.60L of a 0.20/molL sodium thiosulfate Na2S2O3 solution to a

1. A chemist adds 0.60L of a 0.20/molL sodium thiosulfate Na2S2O3 solution to a reaction flask. Calculate the millimoles of sodium thiosulfate the chemist has added to the flask. …

1. A chemist is commissioned to produce twenty pallets of aspirin: C 7 H 6 O 3 (

1.                  A chemist is commissioned to produce twenty pallets of aspirin: C7H6O3 (salicylic acid)  + C4H6O3 (acetic anhydride) ?   C9H8O4 (aspirin) +C2H4O2 (acetic acid)…

1. A chemist is commissioned to produce twenty pallets of aspirin: C7H6O3 (salic

1. A chemist is commissioned to produce twenty pallets of aspirin: C7H6O3 (salicylic acid) + C4H6O3 (acetic anhydride) ? C9H8O4 (aspirin) +C2H4O2 (acetic acid) How many kilograms …

1. A chemist needs to determine the concentration of a solution of nitric acid,

1. A chemist needs to determine the concentration of a solution of nitric acid, HNO3. She puts 745 mL of the acid in a flask along with a few drops of indicator. She then slowly a…

1. A chemist recrystallizes 18.23 grams of a solid and recovered 11.11 grams as

1. A chemist recrystallizes 18.23 grams of a solid and recovered 11.11 grams as a first yield and 3.2 grams as a second yield obtained by boiling the mother liquor from the first …

1. A chromoly (a 41xx series steel) steel ball bearing weighs 4.516 grams. It co

1. A chromoly (a 41xx series steel) steel ball bearing weighs 4.516 grams. It contains the following components by weight 0040% Sulfur 010% Silicon 0.035% Phosphorus 0.50% Mangane…

1. A chromoly (a 41xx series steel) steel ball bearing weighs 4.516 grams. It co

1. A chromoly (a 41xx series steel) steel ball bearing weighs 4.516 grams. It contains the following components by weight 0.040% Sulfur 0.20% Silicon 0.035% Phosphorus 0.50% Manga…

1. A chromophore forms in a protein in an autocatalytic process. The protein has

1. A chromophore forms in a protein in an autocatalytic process. The protein has an extinction coefficient at 280 nm of 8500 M cm and the chromophore has an extinction coefficient…

1. A class is an expanded concept of a data structure but it can hold two things

1. A class is an expanded concept of a data structure but it can hold two things which are what? 2. The body of a class declaration serves as the 'prototype' of the class. As such…

1. A class is an expanded concept of a data structure but it can hold two things

1. A class is an expanded concept of a data structure but it can hold two things which are what? 2. The body of a class declaration serves as the 'prototype' of the class. As such…

1. A coil of 100 turns and radius 15.0 cm surrounds a long solenoid of radius 2.

1. A coil of 100 turns and radius 15.0 cm surrounds a long solenoid of radius 2.5 cm and 2000 turns/metre. The current in the solenoid changes as I = (10.0 A) sin(377t). What is t…

1. A collection is a container object (data structure) that represents a group o

1. A collection is a container object (data structure) that represents a group of objects often referred to as data or elements of the collection TRUE FALSE 2. Information hiding …

1. A common biological buffer is a \"Phosphate Buffer,\" which involves the equi

1. A common biological buffer is a "Phosphate Buffer," which involves the equilibrium between H2PO4- and H2PO42- , with a pKa at 25 degree celcius of 6.86. Describe in words how y…

1. A compound is 85.7% carbon and 14.3% hydrogen. Calculate the empirical formul

1. A compound is 85.7% carbon and 14.3% hydrogen. Calculate the empirical formula. 2. What is the empirical formula for a compound if a 2.50 g sample contains 0.900 g if 6 cakcuyn…

1. A compound is found to have the empirical formula CH. If the molecular weight

1. A compound is found to have the empirical formula CH. If the molecular weight of the compound is 78.11, what is the molecular formula of that compound? 2. In the empirical form…

1. A compound possessing a carboxylic acid produces a yellow solution when disso

1.         A compound possessing a carboxylic acid produces a yellow solution when dissolved in diethyl ether. This yellow solution is transferred to a separatory funnel and an aq…

1. A computer system exploits “direct mapping” cache. If cache has 64 blocks of

1. A computer system exploits “direct mapping” cache. If cache has 64 blocks of 16 words, then how many bits are there in the “tag” field of the 15-bit address for this architectu…

1. A container of gas at 4 atm pressure and 112 C is compressed at constant temp

1. A container of gas at 4 atm pressure and 112 C is compressed at constant temperature until the volume is halved. It is then further compressed at a. What is the final pressure …

1. A contestant in the American Chemical Society Laboratory Technician Beauty Co

1. A contestant in the American Chemical Society Laboratory Technician Beauty Contest was described in the following terms: Her hair was like spun [Ar]3d 4s, her skin was as soft …

1. A coupon of very pure Gold and highly clean surface is exposed to an Argon Fl

1. A coupon of very pure Gold and highly clean surface is exposed to an Argon Fluoride (ArF) excimer laser beam of wavelength 193.4±0.2 nm inside an ESCA (Electron Spectroscopy fo…

1. A crime scene investigator measures a tire mark on the street to be 12,200 cm

1. A crime scene investigator measures a tire mark on the street to be 12,200 cm. How many km is this? (Express your answer in standard notation not scientific notation) 2. Conver…