chem

Pataasin ang iyong marka sa homework at exams ngayon gamit ang Quizwiz!

Insoluble

Fe(OH)2 PbS PbBr2 PbF2 CaCO3 AgCl BaSO4 Ag2SO4

Which of these chemical equations describes a metal displacement reaction?

Fe2O3(s) + 2Al(s) → 2Fe(s) + Al2O3(s)

Which is a strong acid?

HClO4

Weak Acid

HF, H3PO4 CH3COOH

A system contracts from an initial volume of 15.0 L to a final volume of 10.0 L under a constant external pressure of 0.80 atm. What is w? (1 L·atm = 101.3 J)

+4.1 ×102 J This feels weird and was not the answer I got but its what makes most sense. I'd say 4*101.3J is more accurate

What is the oxidation number of Cr in Cr2O72-?

+6

What is the oxidation number of sulfur in sulfuric acid?

+6

From these data, S(rhombic) + O2(g) →SO2(g) ΔHorxn= −296.06 kJ/mol S(monoclinic) + O2(g) →SO2(g) ΔHorxn= −296.36 kJ/mol calculate the enthalpy change for the transformation S(rhombic) → S(monoclinic) (Monoclinic and rhombic are different allotropic forms of elemental sulfur.)

.3

The standard enthalpies of formation of ions in aqueous solutions are obtained by arbitrarily assigning a value of zero to H ions; that is, ΔH o f [ H+(aq) ] = 0. (a) For the following reaction HCl(g) H2O → H+(aq) + Cl−(aq) Δ H o rxn = −74.9 kJ/mol calculate Δ H o f for the Cl− ions. (b) Given that ΔHof for OH− ions is −229.6 kJ/mol, calculate the enthalpy of neutralization when 1 mole of a strong monoprotic acid (such as HCl) is titrated by 1 mole of a strong base (such as KOH) at 25 ° C.

-167.2 b.-57

What is ΔH°rxn for the following reaction? 2H2O2(l) → 2H2O(l) + O2(g) ΔH°f(H2O(l)) = -285.8 kJ/mol, ΔH°f(H2O2(l)) = -187.6 kJ/mol

-196.4 kJ/mol

A gas expands and does PV work on its surroundings equal to 335 J. At the same time, it absorbs 107 J of heat from the surroundings. Calculate the change in energy of the gas. Note: PV work means work done by a changing volume against constant pressure. Enter your answer in scientific notation.

-2.28x10E2

In a gas expansion, 7.0 × 101 J of heat is absorbed from the surroundings, and the energy of the system decreases by 132 J. Calculate the work done.

-202

Octane (C8H18) undergoes combustion according to the following thermochemical equation. 2C8H18(l) + 25O2(g) → 16CO2(g) + 18H2O(l) ΔH°rxn = -1.0940 × 104 kJ/mol What is the standard enthalpy of formation of liquid octane? ΔH°f(CO2(g)) = -393.5 kJ/mol and ΔH°f(H2O(l)) = -285.8 kJ/mol

-250 kJ/mol

Predict the enthalpy of reaction from the average bond enthalpies for the following reaction: 2C2H6(g) + 7O2(g) → 4CO2(g) + 6H2O(g)

-2759

What is the change in internal energy in joules for a system that releases 154 J of heat and does 125 J of work on its surroundings?

-279 J

What is the oxidation number of N in K3Fe(CN)6?

-3

A solution is prepared by condensing 3.45 L of a gas, measured at 29.0C and 753 mmHg pressure, into 80.1 g of benzene. Calculate the freezing point of this solution.

-3.31

Use the following bond enthalpies in the table below to estimate Δ Hrxn for the following reaction. 2NCL3 -> N2 + 3Cl2

-469.5

What is ΔH°rxn for the following reaction? 2C8H18(l) + 17O2(g) → 16CO(g) + 18H2O(l) 2C8H18(l) + 25O2(g) → 16CO2(g) + 18H2O(l) ΔH°rxn = -11020. kJ/mol 2CO(g) + O2(g) → 2CO2(g) ΔH°rxn = -566.0 kJ/mol

-6492 kJ/mol

2Al(s) + 32O2(g) → Al2O3(s) ΔHorxn=−1601 kJ/mol 2Fe(s) + 32O2(g) → Fe2O3(s) ΔHorxn=−821 kJ/mol calculate the standard enthalpy change for the following reaction: 2Al(s) + Fe2O3(s) → 2Fe(s) + Al2O3(s)

-7.8x10E2

A system delivers 222 J of heat to the surroundings while delivering 645 J of work. What is the change in the internal energy, ΔU, of the system?

-867 J

The solubility of N2 in blood at 37°C and at a partial pressure of 0.80 atm is 5.6 × 10−4 mol/L. A deep-sea diver breathes compressed air with the partial pressure of N2 equal to 4.4 atm. Assume that the total volume of blood in the body is 4.3 L. Calculate the amount of N2 gas released (in liters at 37°C and 1.00 atm) when the diver returns to the surface of the water, where the partial pressure of N2 is 0.80 atm.

.28

A sample of nitrogen gas in a 2.7-L container at a temperature of 53 ° C exerts a pressure of 3.9 atm. Calculate the number of moles of gas in the sample.

.39

A piece of sodium metal reacts completely with water as follows: 2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g) The hydrogen gas generated is collected over water at 21.0 ° C. The volume of the gas is 275 mL measured at 0.979 atm. Calculate the number of grams of sodium used in the reaction. (The vapor pressure of water at 21.0 ° C = 0.0246 atm.)

.500

The fuel value of hamburger is approximately 3.3 kcal/g. If a man eats 0.25 pounds of hamburger for lunch and none of the energy is stored in his body, estimate the amount of water that would have to be lost in perspiration to keep his body temperature constant. The heat of vaporization of water may be taken as 2.41 kJ/g. (1 lb = 453.6 g)

.65

At 2°C, the vapor pressure of pure water is 23.76 mmHg and that of a certain seawater sample is 23.15 mmHg. Assuming that seawater contains only NaCl, estimate its molal concentration.

.75

A 50.0 mL sample of 0.436 M NH4NO3 is diluted with water to a total volume of 250.0 mL. What is the ammonium nitrate concentration in the resulting solution?

0.0872 M

A sample of nitrogen gas has the temperature drop from 250.°C to 150.°C at constant pressure. What is the final volume if the initial volume is 310. mL?

0.251 L

35.0 mL of 0.255 M nitric acid is added to 45.0 mL of 0.328 M Mg(NO3)2. What is the concentration of nitrate ion in the final solution?

0.481 M

A sample of a gas has an initial pressure of 0.987 atm and a volume of 12.8 L. What is the final pressure if the volume is increased to 25.6 L?

0.494 atm

A gas evolved during the fermentation of sugar was collected at 22.5°C and 702 mmHg. After purification its volume was found to be 25.0 L. How many moles of gas were collected? (R = 0.08206 L • atm/K • mol, 1 atm = 760 mmHg)

0.952 mol

Calculate how much more quickly 235UF6 effuses than 238UF6. Give the answer as the ratio of rates of 235UF6 to 238UF6 to four decimal places.

1.0043

What is the molarity of a solution prepared by diluting 1.85 L of 6.5 M KOH to 11.0 L?

1.1 M

What is the pH of a 0.056 M HNO3 solution?

1.25

Calculate the osmotic pressure of a 0.0571 M MgSO4 solution at 25 ° C. (The van't Hoff factor for MgSO4 is 1.30)

1.82

What is the percent CsCl by mass in a 0.711 M aqueous CsCl solution that has a density of 1.091 g/mL?

11.0%

A gas cylinder containing 1.50 mol compressed methane has a volume of 3.30 L. What pressure does the methane exert on the walls of the cylinder if its temperature is 25°C?

11.1 atm

Calculate the height of a column of benzene (C6H6) that would be supported by atmospheric pressure. The density of benzene is 0.879 g/cm3.

11.75

A fixed quantity of gas has a pressure of 1.35 atm, a volume of 23.8 L, and a temperature of 205.1 K. If the pressure increases to 2.84 atm and the temperature rises to 233.4 K, what is the new volume of the gas?

12.9 L

What is the molar mass of an unknown gas if a sample weighing 0.389 g is collected in a flask with a volume of 102 cm3 at 97°C and at a pressure of 728 mmHg?

121 g/mol

Determine the molar mass of Freon-11 gas if a sample weighing 0.597 g occupies 100 cm3 at 95°C and 1000 mmHg (R = 0.08206 L • atm/K • mol, 1 atm = 760 mmHg).

137 g/mol

What is the density of CO2(g) at 100.°C and 10.0 atm pressure?

14.4 g/L

What pressure (in atm and in bars) is exerted by a column of methanol (CH3OH) 211 m high? The density of methanol is 0.787 g/cm3.

16.28bars 16.07atm

Calculate the mass in grams of hydrogen chloride produced when 5.25 L of molecular hydrogen measured at STP reacts with an excess of molecular chlorine gas. H2(g) + Cl2(g) → 2HCl(g)

17.1

Magnesium metal (0.100 mol) and hydrochloric acid (0.500 mol HCl) are combined and react to completion. What volume of hydrogen gas, measured at STP, is produced? Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)

2.24 L of H2

If 75.4 J of energy is absorbed by 0.25 mol of CCl4 at constant pressure, what is the change in temperature? The specific heat of CCl4 is 0.861 J/g·°C.

2.3°C

What mass of lithium phosphate is needed to prepare 500. mL of a solution having a lithium ion concentration of 0.125 M?

2.41 g

What is the volume of NH3 produced in the following reaction when 3.0 L of N2 reacts with 4.0 L of H2? N2(g) + 3H2(g) → 2NH3(g)

2.7 L

How many calories are in 854.3 J? (1 cal = 4.184 J)

204.2 cal

Copper(II) bromide is used as a wood preservative. What mass of CuBr2 is needed to prepare 750.0 mL of a 1.25 M solution?

209 g

The standard enthalpy change for the following reaction is 436.4 kJ/mol: H2(g) → H(g) + H(g) Calculate the standard enthalpy of formation of atomic hydrogen (H). kJ

218.2

Sodium hydroxide is a common ingredient in drain cleaners such as Drano®. The mole fraction of sodium hydroxide in a saturated aqueous solution is 0.310. What is the molality of the solution?

24.9 m

The solubility of KNO3 is 155 g per 100 g of water at 75°C and 38.0 g at 25°C. What mass(in grams) of KNO3 will crystallize out of solution if exactly 575.0 g of its saturated solution at 75°C is cooled to 25°C?

264

What are the conditions of STP?

273.15 K and 760 torr

What is the Kelvin temperature at 24°C?

297 K

Which equation describes a redox reaction?

2Al(s) + 3H2SO4(aq) → Al2(SO4)3(aq) + 3H2(g)

Which chemical equation describes a combustion reaction?

2C2H6(g) + 7O2(g) → 4CO2(g) + 6H2O(l)

What is the molarity of a solution that is 26.0% by mass phosphoric acid (H3PO4) and that has a density of 1.155 g/mL?

3.06 M

What is the molality of a solution prepared by dissolving 84.7 g of KMnO4 in 165 g of water?

3.25 m

How many sodium ions are present in 325 mL of 0.850 M Na2SO4?

3.33 × 10E23 Na ions

What is the mass, in grams, of 2.74 L of CO gas measured at 33°C and 945 mmHg?

3.80 g

If 2.3 mol of a gas occupies 50.5 mL, how many moles of the gas will occupy 85.5 mL at the same temperature and pressure?

3.9 mol

A pressure that will support a column of Hg to a height of 256 mm would support a column of water to what height? The density of mercury is 13.6 g/cm3; the density of water is 1.00 g/cm3.

348 cm

A gas sample occupying a volume of 21.5 mL at a pressure of 0.733 atm is allowed to expand at constant temperature until its pressure reaches 0.399 atm. What is its final volume?

39.5

Given that 3.39 moles of carbon monoxide gas are present in a container of volume 22.30 L, what is the pressure of the gas (in atm) if the temperature is 91 ° C?

4.54

How many molecules of N2 gas are present in a 2.5-L flask at 50°C and 650 mmHg?

4.9 × 1022 molecules

A 3.10−g sample of a salt dissolves in 7.30 g of water to give a saturated solution at 28°C. What is the solubility (in g salt/100 g of H2O) of the salt?

42.47

Given that CaO(s) + H2O(l) → Ca(OH)2(s), ΔH°rxn = -64.8 kJ/mol, how many grams of CaO must react in order to liberate 525 kJ of heat?

454 g

Consider the reaction 2H2O(g) → 2H2(g) + O2(g) Δ H = +483.60 kJ/mol at a certain temperature. If the increase in volume is 17.7 L against an external pressure of 1.00 atm, calculate Δ U for this reaction. (The conversion factor is 1 L · atm = 101.3 J.)

481.81

A Snickers® candy bar contains 280 Calories, of which the fat content accounts for 120 Calories. What is the energy of the fat content, in kJ? (1 cal = 4.184 J)

5.0 × 102 kJ this confused me. Do more practice probkems on these, DA got me fu

What volume of concentrated (14.7 M) phosphoric acid is needed to prepare 25.0 L of 3.0 M H3PO4?

5.1L

What is q if 28.6 g of water is heated from 22.0°C to 78.3°C? The specific heat of water is 4.184 J/g·°C.

6.74 kJ

If the atmospheric pressure in Denver is 0.8800 atm, what is this pressure expressed in mmHg? (1 atm = 101,325 Pa = 760 torr, 1 torr = 1 mmHg)?

668.8 mmHg

How much heat is required to raise the temperature of 22.8 g of copper from 20.0°C to 875.0°C? The specific heat of copper is 0.385 J/g·°C.

7.51 kJ

The bond enthalpy of F2(g) is 156.9 kJ/mol. Calculate it for for F(g).

78.45

The pressure of 5.75 L of an ideal gas in a flexible container is decreased to one-third of its original pressure, and its absolute temperature is decreased by one-half. What is the final volume of the gas?

8.71

Carbon tetrachloride, once widely used in fire extinguishers and as a dry cleaning fluid, has been found to cause liver damage to those exposed to its vapors over long periods of time. What is the boiling point of a solution prepared by dissolving 375 g of sulfur (S8, 256.5 g/mol) in 1250 g of CCl4? (For CCl4, Kb = 5.05°C/m; boiling point of pure CCl4 = 76.7°C)

82.6C

Dissolving 3.96 g of an impure sample of calcium carbonate in hydrochloric acid produced 0.872 L of carbon dioxide (measured at 20.0 ° C and 719 mmHg). Calculate the percent by mass of calcium carbonate in the sample.

86.67

The mole fraction of oxygen molecules in dry air is 0.2095. What volume of dry air at 1.00 atm and 25°C is required for burning completely 1.00 L of octane (C8H18, density = 0.7025 g/mL), yielding carbon dioxide and water?

8970 rounding? redo this again

A gas-filled balloon with a volume of 2.65 L at 1.20 atm and 20 ° C is allowed to rise to the stratosphere (about 30 km above the surface of the Earth), where the temperature and pressure are −23 ° C and 3.00 × 10−3 atm, respectively. Calculate the final volume of the balloon.

904.5

Based on the solubility rules, which one of these compounds is insoluble in water?

AgBr

Salt

An ionic compound made up of the cation from a base and the anion from an acid.

What are the boiling point and freezing point of a 3.27 m solution of naphthalene in benzene? (The boiling point and freezing point of benzene are 80.1 °C and 5.5°C, respectively.)

BP 88.89 FP -11.2

What is the net ionic equation if sodium sulfate is mixed with barium hydroxide?

Ba2+(aq) + SO42-(aq) → BaSO4(s)

Based on the solubility rules, which of these processes will occur if solutions of CuSO4(aq) and BaCl2(aq) are mixed?

BaSO4 will precipitate; Cu2+ and Cl- are spectator ions.

"The pressure of an ideal gas is inversely proportional to its volume at constant temperature and number of moles" is a statement of ________ law.

Boyle's

A 0.271-g sample of an unknown vapor occupies 294 mL at 140°C and 847 mmHg. The empirical formula of the compound is CH2. What is the molecular formula of the compound?

C2H4

A quantity of 7.630 g of an organic compound is dissolved in water to make 306.0 mL of solution. The solution has an osmotic pressure of 1.43 atm at 27°C. The analysis of this compound shows that it contains 41.8 percent C, 4.7 percent H, 37.3 percent O, and 16.3 percent N. Calculate the molecular formula of the compound.

C15H20O10N5

A certain anesthetic contains 64.9 percent C, 13.5 percent H, and 21.6 percent O by mass. At 121°C and 783 mmHg, 3.30 L of the gaseous compound weighs 7.79 g. What is the molecular formula of the compound?

C4H10O

Which of these compounds is a nonelectrolyte?

C6H12O6 (glucose)

Which compound is the most soluble in water?

CH3CH2CH2OH shortest chain

A compound composed of carbon, hydrogen, and chlorine effuses through a pinhole 0.411 times as fast as neon. What is the molecular formula of the compound?

CHCl3

Which is immiscible with water?

CS2

Which of these chemical equations describes a precipitation reaction?

CaBr2(aq) + H2SO4(aq) → CaSO4(s) + 2HBr(g)

The lattice energy of CaF2 is the energy change corresponding to which process?

CaF2(s) → Ca2+(g) + 2F-(g)

"The volume of an ideal gas is directly proportional to its absolute temperature at constant pressure and number of moles" is a statement of ________ law.

Charles'

What is oxidized in the following reaction? Fe + Ag2O → FeO + 2Ag

Fe

Which is present in all aqueous Brønsted acid solutions?

H+

Which of these compounds is a strong electrolyte?

H2SO4

Strong Acids

HCl, HBr, HNO3, H2SO4, HClO4

What is the quantitative relationship between gas solubility and pressure?

Henry's Law

gases at room temp

Kr Xe Cl N He HCN CO2 HCl

Which chemical equation describes an acid-base neutralization reaction?

LiOH(aq) + HNO3(aq) → LiNO3(aq) + H2O(l)

soluble

LiOh Na2Co3 (NH4)S Ca(C2H3O2)2 (NH4)SO4 Na2CO3 NaNO3 KCl

What is the reducing agent in the following reaction? Mg + NiO2 + 2H2O → Mg(OH)2 + Ni(OH)2

Mg

Precipitation reaction

Mixing a BaCl2 solution with a K2SO4 solution.

weak base

NH3

If aqueous solutions of Pb(NO3)2 and NaCl are mixed, which ions, if any, are spectator ions? Pb(NO3)2(aq) + 2NaCl(aq) → PbCl2(s) + 2NaNO3(aq)

Na+(aq), NO3-(aq)

Based on the solubility rules, which one of these compounds is soluble in water?

Na2S

Complete the following reaction and identify the Brønsted acid. NaOH(aq) + HCl(aq) →

NaCl(aq) + H2O(l); HCl is the acid.

Salts

NaF BaSO4 KBr

Strong bases

NaOH, KOH, Ca(OH)2 Sr(OH)2 Ba(OH)2 LiOH

Which of the following accurately lists compounds in order of increasing solubility in water?

O2, Br2, LiCl, methanol (CH3OH)

A sample of ammonia (NH3) gas is completely decomposed to nitrogen and hydrogen gases over heated iron wool. If the total pressure is 615 mmHg after the reaction, calculate the partial pressures of N2 and H2. Enter your answers in scientific notation.

PN2 is 1.54x10E2 PH2 is 4.61x10E2

If aqueous solutions of lead(II) nitrate and sodium sulfate, which insoluble precipitate is formed?

PbSO4

Which is the correct description of a solution?

Somehow not "A solution is a homogeneous mixture of two or more substances." ???????

What is the [H+] in a solution with a pH of 5.63?

Somehow not 2.344x10E-6 M H+, so maybe just 2.3x10E-6M H+? Sigfigs go stupid fr

Which is not a property of a gas?

The densities of gases are much larger than those of corresponding liquids.

A solution of potassium hydroxide is in equilibrium with undissolved solute at 45°C. What will happen if the temperature is raised to 50°C? (ΔHsoln = -57.6 kJ/mol)

The mass of undissolved KOH will decrease.

For the reaction: 2A + B2 → 2AB ΔH = +50.0 kJ.

The reaction is endothermic.

Which of the following processes always results in an increase in the energy of a system?

The system gains heat and has work done on it by the surroundings.

Which is a correct description of the following reaction? H2SO4 + Cd(OH)2 → 2H2O + CdSO4

This reaction is an acid-base reaction.

What is the formula that describes the relationship between the volume and temperature at constant pressure and constant number of moles?

V = k2T

The substance NH3 is considered to be

a weak base.

Calculate the molality of each of the following solutions: (a) 24.8 g of sucrose (C12H22O11) in 311 g of water, (b) 7.83 moles of ethylene glycol (C2H6O2) in 1809 g of water.

a. .233 b. 4.328

A gas expands in volume from 34.5 mL to 94.6 mL at constant temperature. (a) Calculate the work done (in joules) if the gas expands against a vacuum: Enter your answer in scientific notation. (b) Calculate the work done (in joules) against a constant pressure of 3.5 atm: Enter your answer in scientific notation. (c) Calculate the work done (in joules) against a constant pressure of 10.1 atm: Enter your answer in scientific notation.

a. 0 b. -2.3x10E1 c. -6.15x10E1

A sample of air occupies 4.00 L when the pressure is 1.90 atm. (a) What volume does the sample occupy at 7.50 atm at the same temperature?(b) What pressure is required in order to compress it to 0.0290 L at the same temperature?

a. 1.013 b. 262

Calculate the molalities of the following aqueous solutions: (a) 0.948 M sugar (C12H22O11) solution (density of solution = 1.095 g/mL) (b) 1.03 M NaOH solution (density of solution 1.082 g/mL) (c) 3.00 M NaHCO3 solution (density of solution 1.077 g/mL)

a. 1.23 b. .990 c. 3.63

A 0.3175−g sample of solid magnesium is burned in a constant-volume bomb calorimeter that has a heat capacity of 3024 J/ ° C. The temperature increases by 2.599 ° C. (a) Calculate the heat given off by the burning Mg in kJ/g. (b) Calculate the heat given off by the burning Mg in kJ/mol.

a. 24.75 b. 602

Determine the partial pressure and number of moles of each gas in a 16.75−L vessel at 30.0 ° C containing a mixture of xenon and neon gases only. The total pressure in the vessel is 6.90 atm, and the mole fraction of xenon is 0.731. a. What is the partial pressure of xenon? b. What is the number of moles of xenon? c. What is the partial pressure of neon? d. What is the number of moles of neon?

a. 5.04 b. 3.4 c. 1.86 d. 1.25

Calculate the amount of water (in grams) that must be added to (a) 6.50 g of urea [(NH2)2CO] in the preparation of a 10.00 percent by mass solution, (b) 30.5 g of MgBr2 in the preparation of a 3.40 percent mass solution

a. 58.5 b. 866.5

What are the normal freezing points and boiling points of the following solutions? (a) 22.1 g NaCl in 129 mL of water. [Assume the van′t Hoff factor (i) is equal to 1.8.](b) 16.1 g of urea [(NH2)2CO]in 76.7 mL of water.

a. FP -9.8 BP 102.7 b. FP -6.5 BP 101.8

The specific heat (capacity) is

amount of energy needed to change 1 g of a substance by 1°C.

The mixing of solvent molecules and solute molecules is usually described as

an exothermic process.

Nitrogen will behave most like an ideal gas

at high temperature and low pressure.

Which of the following is not a colligative property?

atmospheric pressure

What is the temperature at which a substance's vapor pressure equals the external atmospheric pressure?

boiling point

Which type of system may transfer energy, but not mass, to the surroundings?

closed system

Which process defines how an ionic compounds break apart into its constituent ions upon dissolution?

dissociation

Which represents the definition of pressure?

force/area

What is defined as the difference between the freezing point of a pure solvent and the freezing point of the solution?

freezing-point depression

Which of these is not a state function?

heat, work

A Born-Haber cycle applied to the formation reaction of an ionic solid

is an application of Hess's law.

Deviations from the ideal gas law are greater at

low temperatures and high pressures.

The vapor pressure of ethanol (C2H5OH) at 20°C is 44 mmHg, and the vapor pressure of methanol (CH3OH) at the same temperature is 94 mmHg. A mixture of 26.3 g of methanol and 47.1 g of ethanol is prepared and can be assumed to behave as an ideal solution. Calculate the vapor pressure of methanol and ethanol above this solution at 20°C. Be sure to report your answers to the correct number of significant figures. Then, Calculate the mol fraction of methanol and ethanol in the vapor above this solution at 20°C.

methanol 42 ethanol 24 methanol .63 ethanol .37

What term describes the process when two liquids are completely soluble in each other in all proportions?

miscible

The elemental analysis of an organic solid extracted from gum arabic (a gummy substance used in adhesives, inks, and pharmaceuticals) showed that it contained 40.0 percent by mass C, 6.7 percent by mass H, and 53.3 percent by mass O. A solution of 0.605 g of the solid in 21.1 g of the solvent diphenyl gave a freezing-point depression of 1.91°C. Calculate the molar mass and molecular formula of the solid. (Kf for diphenyl is 8.00°C/m.)

molar mass 1.2x10E2 Molecular formula C4H8O4

At 29 ° C, 10 moles of a gas in a 1.40−L container exert a pressure of 130 atm. Is this an ideal gas?

nonideal

What is the name for a solute that does not exert a vapor pressure when it is dissolved in a liquid?

nonvolatile

Which solution is basic?

pH = 10.00

A system that does no work but which transfers heat to the surroundings has

q < 0, ΔU < 0

When heat is absorbed by the system and work is done by the system on the surroundings then

q is positive and w is negative.

What is the name given to a solution that contains the maximum amount of solute that will dissolve in a solvent at a specific temperature?

saturated

What name is given to a minor component in a solution?

solute

Which substance is present in the smallest proportion in a solution?

solute

What is the name given to the process when solvent molecules surround the solute molecules?

solvation

The molecules of different samples of an ideal gas have the same average kinetic energies at the same ________.

temp

If two solutions are mixed together in a container and the container "feels hot", then

the reaction is exothermic.

When two pure substances are mixed to form a solution

there is an increase in entropy.

Which of the following is not soluble in water?

vitamin E

The structure of Vitamin B1, thiamine, is shown here. Vitamin B1 is most soluble in

water

Which is the symbol used for the enthalpy change?

ΔH

Which is the symbol used for the entropy change?

ΔS

Consider the reaction H2(g) + Cl2(g) → 2HCl(g) Δ H = −184.6 kJ/mol If 4.0 moles of H2 reacts with 4.0 moles of Cl2 to form HCl at 1.0 atm, what is Δ U for this reaction? Assume the reaction goes to completion and Δ V = 0 L.(The conversion factor is 1 L · atm = 101.3 J.)

ΔU = -740


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