Chemistry concepts and calculations

1.) A 10g example of an oxide of copper when heated in a stem of hydrogen forms

1.) A 10g example of an oxide of copper when heated in a stem of hydrogen forms 1.26g of water. What is % of copper by mass in the compound? 2.) A sample of ammonium dichromate co…

1.) A 2.00 gram sample containing graphite (carbon) and aninhert substance was b

1.) A 2.00 gram sample containing graphite (carbon) and aninhert substance was burned in oxygen and produced a mixture ofcarbon dioxide and carbon monoxide in the mole ratio of 2.…

1.) A 2.3014 g sample was digested, dissolved, and treated with barium ion to pr

1.) A 2.3014 g sample was digested, dissolved, and treated with barium ion to precipitate the sulfate as BaSO4. After filtration, washing and drying, the dry weight is 0.7586 g. W…

1.) A balloon contains 3.56L of helium at a temperature of 28.8 o C and a pressu

1.) A balloon contains 3.56L of helium at a temperature of 28.8oC and a pressure of 1.03 atm. What is the mass of helium in the balloon? 2.) At a certain temperature the vapor pre…

1.) A balloon is floating around outside your window. The temperature outside is

1.) A balloon is floating around outside your window. The temperature outside is -13 C , and the air pressure is 0.700 atm . Your neighbor, who released the balloon, tells you tha…

1.) A compound has the following percentage composition, by weight: 22.0% Cu, 12

1.)A compound has the following percentage composition, by weight: 22.0% Cu, 12.9% Fe, 16.6% C, 19.4% N, and 29.1% H2O. Write a plausible (empirical) formula for this compound. 2.…

1.) A compound has two amino/aminium groups and one carboxyl/carboxylate group.

1.) A compound has two amino/aminium groups and one carboxyl/carboxylate group. The respective pKas are 8.1, 10.1, and 2.1. To the nearest tenth of a unit, what is the isoelectric…

1.) A compound has two amino/aminium groups and one carboxyl/carboxylate group.

1.) A compound has two amino/aminium groups and one carboxyl/carboxylate group. The respective pKas are 8.1, 10.1, and 2.1. To the nearest tenth of a unit, what is the isoelectric…

1.) A corporation owns and operates a company that procues and distributes mater

1.) A corporation owns and operates a company that procues and distributes materials used in explosives. As a result of a 5 gallon drum of ignitable material left open adjacent to…

1.) A flask is charged with 0.100 mol of A and allowed to react to form B accord

1.) A flask is charged with 0.100 mol of A and allowed to react to form B according to the hypothetical gas-phase reaction A(g) ---------> B(g). The following data are collecte…

1.) A flask is charged with 0.100 mol of A and allowed to react to form B accord

1.) A flask is charged with 0.100 mol of A and allowed to react to form B according to the hypothetical gas-phase reaction A(g) ---------> B(g). The following data are collecte…

1.) A gas is found to have a density of 3.165 g/L at STP. What is its molar mass

1.) A gas is found to have a density of 3.165 g/L at STP. What is its molar mass? Which of the following gases is it most likely to be? Molar Mass: _________ a. NH3 b. O2 c. Cl2 d…

1.) A liquid placed in a closed container will evaporate until equilibrium is re

1.) A liquid placed in a closed container will evaporate until equilibrium is reached. At equilibrium, which of the statements is false? 2.) The normal boiling point of liquid E i…

1.) A mixture of neon and helium gases is maintained in a 5.28 L flask at a pres

1.) A mixture of neon and helium gases is maintained in a 5.28 L flask at a pressure of 3.49 atm and a temperature of 63 °C. If the gas mixture contains 4.98 grams of neon, the nu…

1.) A pilot balloon containing 320 liters of helium gas at 730 mm Hg and 27?C ri

1.) A pilot balloon containing 320 liters of helium gas at 730 mm Hg and 27?C rises to a height of 10,000 feet, where the pressure is 500 mm Hg and the temperature is -33?C. What …

1.) A projectile is launched with an initial speed of 40.0 m/s at an angle of 30

1.) A projectile is launched with an initial speed of 40.0 m/s at an angle of 30.0° above the horizontal. The projectile lands on a hillside 4.00 s later. Neglect air friction. (a…

1.) A protein solution containing 70.0 mg of the protein (dissolved in water) di

1.) A protein solution containing 70.0 mg of the protein (dissolved in water) displays an osmotic pressure of 319.88 Pa at 310.15 K. If the volume of the protein solution is 20.0 …

1.) A quality control scientist at Dow Chemical tried to determine the purity of

1.) A quality control scientist at Dow Chemical tried to determine the purity of NaOH using acid base titration. He measured out 0.500 g of the NaOH sample, and dissolved it in 20…

1.) A sample of 20.0mL sodium carbonate of 0.05M was titrated against hydrochlor

1.) A sample of 20.0mL sodium carbonate of 0.05M was titrated against hydrochloric acid was taken in a burette. The color of the indicator changed when the burette reading read 25…

1.) A sample of a substance with the empirical formula XBr2 weighs 0.5957 g. Whe

1.) A sample of a substance with the empirical formula XBr2 weighs 0.5957 g. When it is dissolved in water and all its bromine is converted to insoluble AgBr by addition of an exc…

1.) A sample of gas with an initial volume of 34.5 L at a pressure of 765 mmHg a

1.) A sample of gas with an initial volume of 34.5 L at a pressure of 765 mmHg and a temperature of 325 K is compressed to a volume of 15.4 L and warmed to a temperature of 430 K …

1.) A sample of gaseous hydrogen gas was collected by the displacement of water

1.) A sample of gaseous hydrogen gas was collected by the displacement of water at 21.8°C and a barometric pressure of 752 torr. The volume under these conditions was measured to …

1.) A sample of gaseous hydrogen gas was collected by the displacement of water

1.) A sample of gaseous hydrogen gas was collected by the displacement of water at 21.8°C and a barometric pressure of 752 torr. The volume under these conditions was measured to …

1.) A sample of hydrogen gas at 286 K and 0.570 atm occupies a volume of 4.55 L.

1.) A sample of hydrogen gas at 286 K and 0.570 atm occupies a volume of 4.55 L. If the pressure of the gas is increased, while at the same time it is heated to a higher temperatu…

1.) A sample of sulfur dioxide at a pressure of 1.00 atm and a temperature of 20

1.) A sample of sulfur dioxide at a pressure of 1.00 atm and a temperature of 202 K is heated at constant pressure to a temperature of 245 K. Which of the following are true? Choo…

1.) A solution containing iodide ions has a percent transmittance reading of 72.

1.) A solution containing iodide ions has a percent transmittance reading of 72.3%. what is the molarity of the iodide ion in this solution. 2.) A solution was made by dissolving …

1.) A solution of 0.156m NaOH is used to titrate 32.0mL of a solution of H2SO4.

1.) A solution of 0.156m NaOH is used to titrate 32.0mL of a solution of H2SO4. If 23.8mL of the NaOH solution is required to reach the endpoint, what is the molarity of the H2SO4…

1.) A solution of NaOH was standardized. An average of 32.12mL of the base was r

1.) A solution of NaOH was standardized. An average of 32.12mL of the base was required to titrate 10.00mL of .3501M HCl standard to a phenolphthalein end point. Calculate the con…

1.) A solution of potassium chloride (KCl) is prepared by dissolving 9.63 g of t

1.) A solution of potassium chloride (KCl) is prepared by dissolving 9.63 g of the salt in 1.00 kg water (H2O). What is the freezing point of this solution? (The freezing point of…

1.) A solution of potassium chloride (KCl) is prepared by dissolving 9.63 g of t

1.) A solution of potassium chloride (KCl) is prepared by dissolving 9.63 g of the salt in 1.00 kg water (H2O). What is the freezing point of this solution? (The freezing point of…

1.) A student finds the melting point of a pure compound to be 112 - 114°C. If a

1.) A student finds the melting point of a pure compound to be 112 - 114°C. If a small impurity were added to the compound, the student should expect the melting point to be: a) &…

1.) A student titrated 25.0mL of a buffer with 0.126 M HCL. What is the concentr

1.) A student titrated 25.0mL of a buffer with 0.126 M HCL. What is the concentration of the weak base in the buffer? Document your logic(do not use M1V1=M2V2) http://i1190.photob…

1.) A typical 2 m2 solar panel produces 250 W of power and costs $200. Assuming

1.) A typical 2 m2 solar panel produces 250 W of power and costs $200. Assuming a capacity factor of 25% (i.e. good sunshine for 6 hours per day), how much would it cost to replac…

1.) According to the Nernst equation, how much should the cell potential change

1.) According to the Nernst equation, how much should the cell potential change if the aqueous component of one of the half cells is changed by a factor of 10? 2.)Which species is…

1.) Acidification of sodium bicarbonate (NaHCO3) produces carbon dioxide in a 2-

1.) Acidification of sodium bicarbonate (NaHCO3) produces carbon dioxide in a 2-step process. The first step produces carbonic acid (H2CO3). Wtite and balance the molecular equati…

1.) Aluminum Metal, Al, reacts with oxygen gas, O 2 , to produce aluminum oxide,

1.) Aluminum Metal, Al, reacts with oxygen gas, O2, to produce aluminum oxide, Al2O3. Which reactant is the limiting reagent when 35.0 grams of Al reacts with 35.0 grams of O2? (U…

1.) An 4.4 kg object gains height 6 while being accelerated from rest to a final

1.) An 4.4 kg object gains height 6 while being accelerated from rest to a final speed of 6.5 m/s by an external force. What was the net work (in J) done on the object? Let g = 9.…

1.) An automobile mechanic mixes ethylene glycol with water to make a solution o

1.) An automobile mechanic mixes ethylene glycol with water to make a solution of automobile antifreeze. This mixture contains 1104g of ethylene glycol and 1.50 kg of pure water. …

1.) An energy bill indicates that the customer used 953 kWh in July.How many jou

1.) An energy bill indicates that the customer used 953 kWh in July.How many joules did the customer use? E = J 2.) An adult eats food whose nutritional energy totals approximatel…

1.) An iceberg initially at 273 K is stopped in its motion by a small island. Du

1.) An iceberg initially at 273 K is stopped in its motion by a small island. During the first few seconds of contact, 20 kJ of energy is transferred thermally from the island to …

1.) Assuming complete dissociation, what is the pH of a 3.51 mg/L Ba(OH)2 soluti

1.) Assuming complete dissociation, what is the pH of a 3.51 mg/L Ba(OH)2 solution? **Is there a specific formula for this, please help! 2.) Enough of a monoprotic acid is dissolv…

1.) At a certain temperature the K sp of Ag 2 SO 4 is 1.73 x 10 -5 . What is the

1.) At a certain temperature the Ksp of Ag2SO4 is 1.73 x 10-5. What is the molar soliubility of silver sulfate in water in units of M (mol/liter). 2.) The Ksp of BaCO3 is 5.0 x 10…

1.) At higher temperatures, the fraction of molecules with enough energy to over

1.) At higher temperatures, the fraction of molecules with enough energy to overcome the activation energy barrier is ______. a) larger b)smaller c) same 2.) Rates increase with i…

1.) Based on the molecular formula, determine if each compound is an alkane, alk

1.) Based on the molecular formula, determine if each compound is an alkane, alkene, or an alkyne. (Assume that all compounds are noncyclic and do not contain more than one multip…

1.) Based on what you can find regarding the anticipated frequencies of carbonyl

1.) Based on what you can find regarding the anticipated frequencies of carbonyl vibrations, which carbonyl in the recrystallized product structure do you expect to have the highe…

1.) Boston Harbor The Massachusetts Water Resources Authority (MWRA) claims that

1.) Boston Harbor The Massachusetts Water Resources Authority (MWRA) claims that the $3.8 Billion dollar Boston Harbor Cleanup has been a great success. a.) Please present evidenc…

1.) C 3 H 8 + O 2 -> CO 2 + H 2 O How many grams of CO 2 can be produced by burn

1.) C3H8 + O2 -> CO2 + H2O How many grams of CO2 can be produced by burning 3.65 moles of propane? Assume oxygen is the excess reagent in this reaction. 2.) 6Li + N2 -> 2Li3…

1.) CSI find that a car hit thr ground 60m from the point where it left the clif

1.) CSI find that a car hit thr ground 60m from the point where it left the cliff. The cliff is 45m high. What speed was the car going when it left the cliff? 2.) A speeding car m…

1.) Calculate the change in internal energy of the following system: a balloon i

1.) Calculate the change in internal energy of the following system: a balloon is cooled by removing 0.655kJ of heat. It shrinks on cooling, and the atmosphere does 387J of work o…

1.) Calculate the change in internal energy of the following system: a balloon i

1.) Calculate the change in internal energy of the following system: a balloon is cooled by removing 0.655kJ of heat. It shrinks on cooling, and the atmosphere does 387J of work o…