Qualitative analysis Questions and Answers

Calculate the internal energy change for each of the following. a. One hundred (100.) joules of work is required to compress a gas. At the same time, the gas releases 46 J of heat. Internal energy change = Piston is compressed from a volume of 5.05 L to 1.15 L against a constant pressure of 3.70 atm. In the process, there is a heat gain by the system of 671 J. Internal energy change = c. A piston expands against 2.05 atm of pressure from 19.0 L to 31.4 L. In the process, 1687 J of heat is absorbed. Internal energy change =

Real gases are those that: Oare only available naturally in the earth's atmosphere. Oonly behave ideally at high pressures or low temperatures. have an even number of protons. are called real gases because their behavior can easily be modeled. deviate from ideal behavior.

A sealed balloon is filled with 1.00 L helium at 22°C and 1.00 atm. The balloon rises to a point in the atmosphere where the pressure is 30.7 torr and the temperature is -55°C. What is the change in volume of the balloon as it ascends from 1.00 atm to a pressure of 30.7 torr?

A mixture of carbon dioxide and neon gases is maintained in a 6.37 L flask at a pressure of 3.14 atm and a temperature of 25 °C. If the gas mixture contains 13.6 grams of carbon dioxide, the number of grams of neon in the mixture is __g.

A 149.3-g sample of a metal at 75.1°C is added to 149.3 g H₂0 at 14.6°C. The temperature of the water rises to 18.8°C. Calculate the specific heat capacity of the metal, assuming that all the heat lost by the metal is gained by the water. The specific heat capacity of water is 4.18 J/°C-g-

The van der Waals equation, nRT = [P+ a(n/V)2] (V-nb), incorporates corrections to the ideal gas law in order to account for the properties of real gases. One of the corrections accounts for the quantum behavior of molecules. the possibility of chemical reaction between molecules. the possibility of phase changes when the temperature is decreased or the pressure is increased. the fact that average kinetic energy is inversely proportional to temperature. Othe finite volume of molecules.

Oxygen gas, generated by the reaction 2KCIO3(s) → 2KCl(s) + 30₂(g) is collected over water at 27°C in a 3.27-L vessel at a total pressure of 1.00 atm. (The vapor pressure of H₂at 27°C is 26.0 torr.) How many moles of KCIO3 were consumed in the reaction? 0.0855 moles 0.192 moles O3.16 moles 0.0916 moles 0.128 moles

Which of the following is true about the kinetic molecular theory? Pressure is due to the collisions of the gas particles with the walls of the container. The volume of a gas particle is considered to be small about 0.10 mL. Gas particles repel each other, but do not attract one another. Adding an ideal gas to a closed container will cause an increase in temperature. At least two of these statements are correct.

A mixture of neon and xenon gases at a total pressure of 716 mm Hg contains neon at a partial pressure of 429 mm Hg. If the gas mixture contains 2.78 grams of neon, how many grams of xenon are present?

A sample of neon gas at a pressure of 987 mm Hg and a temperature of 59 °C, occupies a volume of 11.6 liters. If the gas is cooled at constant pressure to a temperature of 30 °C, the volume of the gas sample will be ___ L.

A mixture of nitrogen and krypton gases, at a total pressure of 768 mm Hg, contains 4.19 grams of nitrogen and 15.8 grams of krypton. What is the partial pressure of each gas in the mixture?

The rate of effusion of O₂ gas through a porous barrier is observed to be 3.45 x 10^-4 mol/h. Under the same conditions, the rate of effusion of O3 gas would be ___ mol/h.

A sample of O₂ gas is observed to effuse through a pourous barrier in 3.56 minutes. Under the same conditions, the same number of moles of an unknown gas requires 2.48 minutes to effuse through the same barrier. The molar mass of the unknown gas is ___ g/mol.

When aqueous solutions of chromium(II) nitrate and ammonium carbonate are combined, solid chromium(II) carbonate and a solution of ammonium nitrate are formed. The net ionic equation for this reaction is:

Write the balanced net ionic equation for the precipitation of zinc sulfide from aqueous solution:

Does a reaction occur when aqueous solutions of calcium chloride and cobalt(II) sulfate are combined? yes no If a reaction does occur, write the net ionic equation.

a. Do the proton and the neutron have exactly the same mass? b. How do the masses of the proton and the neutron compare to the mass of the electron? c. Which particles make the greatest contribution to the mass of an atom? (Select all that apply.) protons neutrons electrons

What volume of bromine monochloride is produced when 24.5 liters of bromine react according to the following reaction? (All gases are at the same temperature and pressure.) bromine(g) + chlorine(g) → bromine monochloride(g)

Suppose you have a sample of sodium weighing 14.00 g. How many atoms of sodium are present in the sample? What mass of potassium would you need to have the same number of potassium atoms as there are sodium atoms in the sample of sodium?

For a particular process q = -17 kJ and w = 21 kJ. Which of the following statements is false? The system does work on the surroundings. Heat flows from the system to the surroundings. ΔE = +4 KJ The process is exothermic. None of these choices is false.

A sample of gas contains 0.1500 mol of CH4(g) and 0.3000 mol of O₂(g) and occupies a volume of 14.7 L. The following reaction takes place: CH4(g) +20₂(g) → CO₂(g) + 2H₂O(g) Calculate the volume of the sample after the reaction takes place, assuming that the temperature and the pressure remain constant.

A graduated cylinder was filled to 25.0 mL with liquid. A solid object weighing 73.5 grams was immersed in the liquid, raising the liquid level to 43.9 mL. Calculate the density of the solid object.

If you were travelling outward from the earth in a space shuttle at an altitude of 38.3 km you would be in the ____________

How many grams of iron are needed to completely consume 3.17 L of oxygen gas according to the following reaction at 25 °C and 1 atm? iron (s) + oxygen (g) iron(II) oxide (s)

A 1.29 mol sample of O₂ gas is confined in a 32.4 liter container at 33.5 °C. If 1.29 mol of H₂ gas is added holding the volume and temperature constant, the average molecular speed of the total system will remain the same increase decrease not enough information to answer the question

A 0.771 mol sample of He gas is confined in a 18.4 liter container at 18.2 °C. If 0.771 mol of CO₂ is substituted for the 0.771 mol of He, holding the volume and temperature constant, the average kinetic energy will increase decrease not enough information to answer the question remain the same

In the following 2-D illustrations, assume that the gas molecules are in motion and that if there is a larger box it indicates a larger volume for the container holding the molecules. A 30 molecules B 10 molecules If both gas samples are at the same pressure, the sample in box A has the highest temperature. both samples are at the same temperature. it is not possible to say anything about the relative temperatures. the sample in box B has the highest temperature.

A sample of gas contains 0.1900 mol of C₂H4(g) and 0.1900 mol of H₂O2(g) and occupies a volume of 15.2 L. The following reaction takes place: C₂H4(g) + H₂O₂(g)CH₂OHCH₂OH(g) Calculate the volume of the sample after the reaction takes place, assuming that the temperature and the pressure remain constant.

For each of the following unbalanced chemical equations, suppose 1.35 g of each reactant is taken. Determine which reactant is limiting, and calculate what mass of each product is expected (assuming that the limiting reactant is completely consumed). UO₂ (s) + HF (aq) → UF4 (aq) + H₂O(1) a. Limiting reactant: Mass of UF4 = Mass of H₂O = b. Limiting reactant: NaNO3(aq) + H₂SO4 (aq) → Na2SO4 (aq) + HNO3(aq) Mass of Na2SO4 = Mass of HNO3 =

A sample of gas contains 0.1700 mol of N₂(g) and 0.5100 mol of H₂(g) and occupies a volume of 36.9 L. The following reaction takes place: N₂(g) + 3H₂(g) →2NH3(g) Calculate the volume of the sample after the reaction takes place, assuming that the temperature and the pressure remain constant.

Complete the reaction. Mercuric oxide → + Mercury. Oxide Oxygen Carbon dioxide Nitrogen

Exactly 149.0 J will raise the temperature of 10.0 g of a metal from 25.0°C to 60.0°C. What is the specific heat capacity of the metal? 0.426 J/g °C 20.7 J/g °C 35.6 J/g °C O2.35 J/g °C None of these choices are correct.

In the laboratory a student finds that it takes 25.3 Joules to increase the temperature of 10.9 grams of gaseous xenon from 23.8 to 39.7 degrees Celsius.

Given the equation 3A + B → C + D, you react 2 moles of A with 1 mole of B. Which of the following is true? A is the limiting reactant because you need 3 moles of A and have 2. B is the limiting reactant because 3 A molecules react with 1 B molecule. A is the limiting reactant because of its higher molar mass. B is the limiting reactant because you have fewer moles of B than A. Neither reactant is limiting.

A sample of solid magnesium is heated with an electrical coil. If 210. Joules of energy are added to a 13.3 gram sample and the final temperature is 37.8°C, what is the initial temperature of the magnesium?

Given the standard enthalpy changes for the following two reactions: (1) Zn(s) + Cl₂(g) → ZnCl₂(s) ΔH°-415.0 kJ (2) Pb(s) + Cl₂(g) → PbCl₂(s) ΔH° -359.4 kJ what is the standard enthalpy change for the reaction: (3) Zn(s) + PbCl₂(s) → ZnCl₂(s) + Pb(s) ΔH° = ?

A 12.0-g sample of HF is dissolved in water to give 2.0 x 10^2 mL of solution. The concentration of the solution is: 0.06 M 6.0 M 3.0 M 0.12 M 0.60 M

A 9.55-g sample of a solid was placed in a 15.00-mL flask. The remaining volume was filled with benzene, in which the solid is insoluble. The solid and benzene together weigh 19.33 g. The density of the benzene is 0.876 g/mL. What is the density of the solid?

What is the energy change when the temperature of 13.3 grams of solid magnesium is decreased from 37.8 °C to 22.3 °C ?

When aqueous solutions of potassium carbonate and cobalt(II) iodide are combined, solid cobalt(II) carbonate and a solution of potassium iodide are formed. The net ionic equation for this reaction is:

Jason set up a textile mill in his hometown in 1865. He became a rich businessman by the time his son Earl took over the business in 1895. Soon after Earl started heading the business, the government passed laws to regulate business and protect consumers and workers. Due to this move by the government, the textile mill had to introduce a fixed salary structure for its employees and implement quality checks for the products manufactured. In the context of the history of American business, Jason had set up this textile mill in the ______

Many plants are poisonous because their stems and leaves contain oxalic acid, H₂C₂O4, or sodium oxalate, Na2C2O4; when ingested, these substances cause swelling of the respiratory tract and suffocation. A standard analysis for determining the amount of oxalate ion, C₂O4², in a sample is to precipitate this species as calcium oxalate, which is insoluble in water. Choose the right net ionic equation for the reaction between sodium oxalate and calcium chloride, CaCl2, in aqueous solution. 2Ca²+ (aq) + C₂04² (aq) → Ca₂C₂O4(s) Ca²+(aq) + C₂O4²- (aq) → CaC₂O4(s) Ca²+ (aq) + 2C₂O4²- (aq) → Ca(C₂O4)2 (8) Ca²+ (aq) + C₂ 04² (aq) → CaC₂O4 (aq)

Identify each of the following unbalanced reaction equations as belonging to one or more of the following categories: precipitation, acid-base, or oxidation-reduction. (Select all that apply.) K₂SO4 (aq) + Pb(NO3)2 (aq) → PbSO4(s) + KNO3(aq) precipitation acid-base oxidation-reduction HCl(aq) + Sr(s) → H₂(g) + SrCl₂ (aq) precipitation acid-base oxidation-reduction HCl(aq) + CsOH(aq) → H₂O(l) + CsCl(aq) c. O precipitation acid-base oxidation-reduction

In the examples cited by Robert Cialdini and Steve Martin, when servers provided mints to their customers as they gave them the bill, the difference in tips from giving one mint versus two mints, jumped from 3 percent to percent of the bill. a. 5 b. 14 c. 6 d. 10

Hexamethylenediamine (C6H16N₂) is one of the starting materials for the production of nylon. It can be prepared from adipic acid (C6H10O4) by the following overall equation: C6H10 O4 (1) 2NH3 (g) + 4H2 (9)→ C6H16N2 (1) + 4H₂O(1) What is the percent yield for the reaction if 1.41 x 10³ g of Percent yield = hexamethylenediamine is made from 1.99 x 10³ g of adipic acid?

A chemist prepares a solution of calcium sulfate (CaSO4) by measuring out 0.33 g of calcium sulfate nto a 250. mL volumetric flask and filling the flask to the mark with water. Calculate the concentration in mol/L of the chemist's calcium sulfate solution. Be sure your answer has the correct number of significant digits.

An unknown piece of metal weighing 68.0g at 90 °C is dropped into a calorimeter that contains 200 grams of 25 °C water. The final temperature of the is 38.3 °C. What is the 8.3°C. What is the specific heat capacity of the unknown metal?

The statement a person receives information that conflicts with their existing beliefs or attitudes, and then alters the information to coincide with those beliefs is indicative of which process? a. Selective exposure b. Selective retention. c. Selective distortion Od. Selective analysis

Choose the balanced equations that show how three of the common strong acids ionize to produce a hydrogen ion. (Select all that apply.) H₂SO4 (aq) → H+ (aq) + HSO4¯ (aq) HCl(aq) → H+ (aq) + Cl(aq) H₂SiO3(aq) → H+ (aq) + HSiO3(aq) HNO3(aq) → H+ (aq) + NO3(aq) HCIO(aq) → H+ (aq) + CIO¯(aq) Q HClO,(aq) → H*(aq) +ClO, (aq)

In 1987 the first substance to act as a superconductor at a temperature above that of liquid nitrogen (77 K) was discovered. The approximate formula of this substance is YBa2Cu3O7. Calculate the percent composition by mass of this material.