Chemistry concepts and calculations

1. A microbiologist desires to study the effect of pH on the growth of E. coli b

1. A microbiologist desires to study the effect of pH on the growth of E. coli bacteria. She plans to do the research by preparing culture media that are buffered at three distinc…

1. A microbiologist desires to study the effect of pH on the growth of E. coli b

1. A microbiologist desires to study the effect of pH on the growth of E. coli bacteria. She plans to do the research by preparing culture media that are buffered at three distinc…

1. A mixture is prepared with(CO]-0.035 M, [C2)]-0.015 M, and [cocl] 0.95 M. It

1. A mixture is prepared with(CO]-0.035 M, [C2)]-0.015 M, and [cocl] 0.95 M. It is known that Ke for the equilibrium CO (g) + Cl2 (g) COCla(g) is 1.2 x 103at 400°C. Predict what w…

1. A mixture of He, Ar, and Xe has a total pressure of 2.10 atm . The partial pr

1. A mixture of He, Ar, and Xe has a total pressure of 2.10 atm . The partial pressure of He is 0.400 atm , and the partial pressure of Ar is 0.350 atm . What is the partial press…

1. A mixture of alcohol and water is 28.00% (v/v) alcohol. How many L of the mix

1. A mixture of alcohol and water is 28.00% (v/v) alcohol. How many L of the mixture do I need in order to have 250.0 mL of alcohol? 2. A mixture of salt and water is 28.0 g salt …

1. A mixture of benzyl alcohol, benzoic acid and benzene is spotted on a silica

1. A mixture of benzyl alcohol, benzoic acid and benzene is spotted on a silica gel TLC plate and is developed in a mixture of 1:1 dichloromethance-methanol as the solvent. Predic…

1. A mixture of helium, nitrogen, and oxygen has a total pressure of 755 mmHg .

1. A mixture of helium, nitrogen, and oxygen has a total pressure of 755 mmHg . The partial pressures of helium and nitrogen are 238 mmHg and 195 mmHg , respectively.What is the p…

1. A mixture of neon, argon and krypton gas has a total pressure of 5.000atm. Th

1. A mixture of neon, argon and krypton gas has a total pressure of 5.000atm. The mixture is 40.00% argon and 25.00% krypton by volume. What is the partial pressure of neon in the…

1. A mixture of three gases is shown in the figure at right. The total pressure

1. A mixture of three gases is shown in the figure at right. The total pressure in this system is 950 torr. (a) Determine the partial pressure of gas C in the mixture. (b) Determi…

1. A mixture of washing soda, Na2CO3* 10 H2O, and sodium chloride, NaCl, is heat

1. A mixture of washing soda, Na2CO3* 10 H2O, and sodium chloride, NaCl, is heated at 150 degree in Celcius to remove the water of hydration. If a 0.2324g sample lost 0.0654 g to …

1. A mole of X reacts at a constant pressure of 43.0 atm via the reaction X(g)+4

1. A mole of X reacts at a constant pressure of 43.0 atm via the reaction X(g)+4Y(g)2Z(g),      H=75.0 kJ Before the reaction, the volume of the gaseous mixture was 5.00 L. After …

1. A monatomic ion with a charge of -2 has an electronic configuration of 1s 2 2

1. A monatomic ion with a charge of -2 has an electronic configuration of 1s22s22p63s23p6. This ion is a(n) _______cation? anion? What is the chemical symbol of the noble gas this…

1. A naturally occuring element consists of two isotopes. Calculate the percent

1. A naturally occuring element consists of two isotopes. Calculate the percent abundances for the two isotopes, if it's average atomic mass is 107.87. Isotope 1: 106.91amu; Isoto…

1. A particle is traveling through space and time encountering gravitational and

1. A particle is traveling through space and time encountering gravitational and electrical forces. Compare the particle's magnitude of displacement with the particle's distance t…

1. A particular reaction has a H o value of -100 kJ and S o of -297 J/mol K at 2

1. A particular reaction has a Ho value of -100 kJ and So of -297 J/mol K at 298 K. Assuming that Ho and So hardly change with temperature, determine the temperature in oC at whic…

1. A particular solvent, at room temperature, dissolves both the impuritie to be

1. A particular solvent, at room temperature, dissolves both the impuritie to be purified. Is this a good solvent for recrystallization of the com answer pou 2. Why, during recrys…

1. A particular solvent, at room temperature, dissolves both the impuritie to be

1. A particular solvent, at room temperature, dissolves both the impuritie to be purified. Is this a good solvent for recrystallization of the com answer pou 2. Why, during recrys…

1. A phase diagram shows conditions (i.e., temperature, pressure, and compositio

1. A phase diagram shows conditions (i.e., temperature, pressure, and composition) at which thermodynamically different phases can be in equilibrium. It can be used to find solubi…

1. A phenomenon called supercooling is frequently encountered in this experiment

1. A phenomenon called supercooling is frequently encountered in this experiment. supercooling, a solution momentarily drops below its freezing point, and then warms up again, bef…

1. A phenomenon called supercooling is frequently encountered in this experiment

1. A phenomenon called supercooling is frequently encountered in this experiment. In supercooling, a solution momentarily drops below its freezing point, and then warms up again, …

1. A pi to pi* transition is the lowest energy absorbtion.because pi bond energy

1. A pi to pi* transition is the lowest energy absorbtion.because pi bond energy is much lower than sigma bond energy. 2. 2,3 pentadiene is chiral because it is an optically activ…

1. A piston-cylinder arrangement with stops (shown in the figure below) contains

1. A piston-cylinder arrangement with stops (shown in the figure below) contains 5 kg of water. Heat is added to the cylinder, bringing it from State 1 to State 3. In State 1. the…

1. A poorly differentiated cancer is best described in appearance as a) close to

1. A poorly differentiated cancer is best described in appearance as a) close to normal cells b) far from normal cells c) having poorly defined nuclei d) having large areas where …

1. A poorly differentiated cancer is best described in appearance as a) close to

1. A poorly differentiated cancer is best described in appearance as a) close to normal cells b) far from normal cells c) having poorly defined nuclei d) having large areas where …

1. A positively charged particle of mass 7.28×10 -8 kg is traveling due east wit

1. A positively charged particle of mass 7.28×10-8kg is traveling due east with a speed of 89.1m/s and enters a 0.300T uniform magnetic field. The particle moves through one-quart…

1. A professor will assign homework today and does not want it due on anybody^?s

1. A professor will assign homework today and does not want it due on anybody^?s holy day. The professor enters today^?s day of the week (0 for Sunday, 1 for Monday, etc.) and the…

1. A pure salt was found to have the composition by mass: 19.1% sodium, 0.84% hy

1. A pure salt was found to have the composition by mass: 19.1% sodium, 0.84% hydrogen, 26.7% sulfur and 53.3% oxygen. Find the empirical formula of the salt. a. Another experimen…

1. A quantity of CO gas occupies a volume of 0.48 L at 1.0 atm and 275 K. The pr

1. A quantity of CO gas occupies a volume of 0.48 L at 1.0 atm and 275 K. The pressure of the gas is lowered, and its temperature is raised until its volume is 1.3 L. Determine th…

1. A quantity of CO gas occupies a volume of 0.48 L at 1.0 atm and 275 K. The pr

1. A quantity of CO gas occupies a volume of 0.48 L at 1.0 atm and 275 K. The pressure of the gas is lowered, and its temperature is raised until its volume is 1.3 L. Determine th…

1. A quantity of heat is added to the machine shown below, causing the gas to ex

1. A quantity of heat is added to the machine shown below, causing the gas to expand and to raise the piston and mass 10 cm. The piston has an area of 2 in^2 and weighs 1 lbm. The…

1. A quantity of heat is added to the machine shown below, causing the gas to ex

1. A quantity of heat is added to the machine shown below, causing the gas to expand and to raise the piston and mass 10 cm. The piston has an area of 2 in^2 and weighs 1 lbm. The…

1. A quantity of heat is added to the machine shown below, causing the gas to ex

1. A quantity of heat is added to the machine shown below, causing the gas to expand and to raise the piston and mass 10 cm. The piston has an area of 2 in^2 and weighs 1 lbm. The…

1. A quantity of heat is added to the machine shown below, causing the gas to ex

1. A quantity of heat is added to the machine shown below, causing the gas to expand and to raise the piston and mass 10 cm. The piston has an area of 2 in^2 and weighs 1 lbm. The…

1. A radioactive decay series that begins with 232 90 Th ends with formation of

1. A radioactive decay series that begins with 23290 Th ends with formation of the stable nuclide 20882 Pb. How many alphaparticle emissions and how many beta-particle emissions a…

1. A radioactive nucleus alpha decays to yield a sodium-24 nucleus in 14.8 hours

1.       A radioactive nucleus alpha decays to yield a sodium-24 nucleus in 14.8 hours. What was the identity of the original nucleus? Show the nuclear equation that leads you to …

1. A reaction in aqueous solution is run in a calorimeter and it is found that t

1. A reaction in aqueous solution is run in a calorimeter and it is found that the the solution gains 99 kJ of heat and the calorimeter gains 5 kJ of heat. What is the heat gained…

1. A reaction in this experiment is started when 3.00 mL of 0.100 M t -butyl chl

1. A reaction in this experiment is started when 3.00 mL of 0.100 M t-butyl chloride is diluted to a final volume of 10.0 mL. After 150 sec, t1/10 has been reached. a. What is the…

1. A reaction in this experiment is started when 3.00 mL of 0.100 M t -butyl chl

1. A reaction in this experiment is started when 3.00 mL of 0.100 M t-butyl chloride is diluted to a final volume of 10.0 mL. After 150 sec, t1/10 has been reached. a. What is the…

1. A reaction is being studied that has the following general form and correspon

1. A reaction is being studied that has the following general form and corresponding rate law: A + B C + D; rate = k[A][B]2 Given this information, which of the following statemen…

1. A reaction rate: Choose one on the order of the reaction a. Has units that de

1. A reaction rate: Choose one on the order of the reaction a. Has units that depends bis constant throughout the reaction c. Has the same units for any reaction d. is positive fo…

1. A reaction system contains C4H10, C4H8, C4H6, and H2. i) Derive a set of inde

1. A reaction system contains C4H10, C4H8, C4H6, and H2. i) Derive a set of independent chemical reactions describing the stoichiometry using Denbigh’s method. ii) Derive a set of…

1. A reaction that is used to propel rockets is N 2 O 4 (l) + 2N 2 H 4 (l) --> 3

1. A reaction that is used to propel rockets is N2O4(l) + 2N2H4(l) --> 3N2(g) + 4H2O(g). This reaction has the advantage that neither product is toxic, so no dangerous pollutio…

1. A representative bottom-hole liquid sample has been analyzed in the laborator

1. A representative bottom-hole liquid sample has been analyzed in the laboratory to determine the solution gas and formation volume factor as a function of pressure. The initial …

1. A researcher studying the nutritional value of a new candy places a 5.90-gram

1. A researcher studying the nutritional value of a new candy places a 5.90-gram sample of the candy inside a bomb calorimeter and combusts it in excess oxygen. The observed tempe…

1. A salt solution approximating ocean water would have the following ionic mola

1. A salt solution approximating ocean water would have the following ionic molalities: chloride, 0.566 m; sodim, 0.485 m; magnesium,, 0.054 m; sulfate, 0.029 m; calcium 0.011 m; …

1. A sample contains BaCl2.2H2O and NaCl. After 0.678 g of sample was heated and

1. A sample contains BaCl2.2H2O and NaCl. After 0.678 g of sample was heated and residue weighted 0.648 g. What is the percent of BaCl2.2H2O in the sample? 2. Do solid NaCl, MgCl2…

1. A sample contains BaCl2.2H2O and NaCl. After 0.678 g of sample was heated and

1. A sample contains BaCl2.2H2O and NaCl. After 0.678 g of sample was heated and residue weighted 0.648 g. What is the percent of BaCl2.2H2O in the sample? 2. Do solid NaCl, MgCl2…

1. A sample of 33.17 mg of chymotrypsin was dissolved in water and diluted to a

1. A sample of 33.17 mg of chymotrypsin was dissolved in water and diluted to a total volume of 5.651 mL. The osmotic pressure of this solution at 25 C was 4.365 torr. What is the…

1. A sample of Br2(g) takes 18.0 min to effuse through a membrane. How long woul

1. A sample of Br2(g) takes 18.0 min to effuse through a membrane. How long would it take the same number of moles of Ar(g) to effuse through the same membrane? Answer: _____ min …

1. A sample of N2O gas has a density of 2.75 g/L at 298 K A) What must be the pr

1. A sample of N2O gas has a density of 2.75 g/L at 298 K A) What must be the pressure of the gas Hg? 2. An experiment shows that a 115 mL gas sample has a mass of 0.172 g at a pr…