Chemistry chapter four fall 2019/spring2020

fall 2019/spring 2020

 Which of the following is NOT in its standard state?

I2 (g)

Which one of the following statements is false?

You feel hot when you sweat because the evaporation of water is an exothermic process.

Which substance involves no intermolecular forces except London dispersion forces?

N2 (s)

Which of the following is the correct order of boiling points for KNO3, CH3OH, C2H6, Ne?

Ne < C2H6 < CH3OH < KNO3

For which of the following reaction(s) is the enthalpy change for the reaction not equal to ΔHf° of the

product?

I. 2H (g) → H2 (g)

II. H2 (g) + O2 (g) → H2O2 (l)

III. H2O (l) + O (g) → H2O2 (l)

I and III

Two substances, A and B, have very different physical properties. A and B do not mix. A boils at 80°C

and freezes at -30°C. B boils at 35°C and freezes at -100°C. Which substance is the least polar?

b. B

Most transition metal oxides such as vanadium(IV) oxide (VO2) undergo a reversible metal→insulator

phase transition in response to external stimuli such as temperature. The metal→insulator transition

temperature TMIT of VO2 occurs at 67°C, but this value can be attenuated by incorporating substitutional

dopants such as W (Whittaker, L., et al. Journal of Materials Chemistry. 2011, 21, 5580-5592.) or interstitial

dopants such as B (Alivio, T. E. G., et al. Chemistry of Materials. 2017, 29, 5401-5412) into the VO2 lattice.

Which of the following analytical techniques would you use to determine the TMIT of B-doped VO2?

differential scanning calorimetry (DSC)

Which statement is inconsistent with the kinetic theory of an ideal gas?

When two gas molecules collide, they both gain kinetic energy.

Which of the following statements is false?

The mean square velocity of molecules in sample A is twice as large as the mean square velocity of molecules in sample B.

Graham's law states that:

d. the rates of effusion of gases are inversely proportional to the square roots of their molar

masses.

Which of the following would you expect to have the highest boiling point?

c. I2

All the following are postulates of the kinetic-molecular theory of gases except:

a. At a constant temperature, each molecule has the same kinetic energy.

At normal atmospheric pressure and a temperature of 0°C, which phase(s) of H2O can exist?

a. Ice and water (l)

22. Consider two gases, A and B, each in their own 1.0 L container with both gases at STP. The mass of

gas A in its container is 0.34 g and the mass of gas B in its container is 0.48 g. Which sample has the most

particles present?

b. both are equal

23. Complete the following: Because real gas particles have attraction for one another,:

d. real gases act more ideally at higher temperatures and lower pressures.

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:

c. the finite volume of molecules.

25. On a cold winter day, a steel metal fence post feels colder than a wooden fence post of identical size

because:

c. the specific heat capacity of steel is lower than the specific heat capacity of wood.

All of the following statements about the greenhouse effect are true

a. the carbon dioxide content of the atmosphere is quite stable.

1. Which of the following is an example of a heterogeneous mixture?

snickers bar

In Bohr's atomic theory, when an electron moves from one energy level to another energy level more distant from the

nucleus,

energy is absorbed

A photon of yellow light has a ____ frequency and a ____ wavelength than a photon of blue light.

lower, longe

 Which of the following is the correct electron configuration of a neutral vanadium atom?

a. 1s22s22p63s23p64s23d

What is the maximum number of electrons that can be identified with the following set of quantum numbers?

n = 4, l = 3, ms = 1

E. 0

An atom of which of the following elements has the smallest radius?

Chlorine

Which of the following will have the highest lattice energy?

a. AlPO4

The correct name for FeO is

d. iron(II) oxide.

Which pair of elements would form a covalent bond that is the least polar?

d. O and F

Which of the following molecules has a permanent dipole moment?

c. NF3

When an atom in a molecule or ion is described as dsp3

-hybridized, its molecular geometry is:

a. trigonal bipyramidal

If four orbitals on one atom overlap four orbitals on a second atom, how many molecular orbitals will form?

8

Aqueous solutions of sodium sulfide and copper(II) chloride are mixed together. Which statement is correct?

c. CuS will precipitate from solution.

Which one of the following statements is false?

c. You feel hot when you sweat because the evaporation of water is an exothermic process.

On a cold winter day, a steel metal fence post feels colder than a wooden fence post of identical size because:

the specific heat capacity of steel is lower than the specific heat capacity of wood.

At normal atmospheric pressure and a temperature of 0°C, which phase(s) of H2O can exist?

a. Ice and water

Which of the following is NOT in its standard state?

b. I2(g)

All the following are postulates of the kinetic-molecular theory of gases except:

c. At a constant temperature, each molecule has the same kinetic energy.

Which of the following gases will have the slowest rate of effusion at constant temperature?

e. CF4

Complete the following: Because real gas particles have attraction for one another,:

d. real gases act more ideally at higher temperatures and lower pressures.

The strongest intermolecular forces between molecules of PH3 are

e. dipole–dipole attractions.

Which of the following concerning intermolecular forces is/are correct?

1. Intermolecular forces depend in part on the molecular geometry of a molecule.

2. London dispersion forces contribute to the net forces of attraction found in all molecular

(covalent) solids and liquids.

3. Hydrogen bonding is a special category of dipole-dipole attractions.

e. 1, 2, and 3

Sulfur trioxide is able to be liquefied at low temperatures due to which intermolecular force?

e. London dispersion

Which of the following pure substances has the lowest normal boiling point?

a. H2S

. The vapor pressure of a liquid increases with increasing temperature. Which of the following statements best explains

this relationship?

The average kinetic energy of molecules is greater; thus, more molecules can enter the gaseous state.

Which of the following is Dr. Alivio's favorite element?

Vanadium