Q: Choose the correct order of increasing band gap for the following materials:

Conductor < Semiconductor < Insulator

Q: Which of the following statements is FALSE regarding colligative properties?

Adding a solute to a solvent generally increases the vapor pressure

Question 1

Which intermolecular force is strongest in a solution of NaCl in water?

Accepted Answer

Ion-dipole interactions

Question 2

Which of the following molecules exhibits dipole-dipole forces as its strongest intermolecular attraction?

Accepted Answer

CO

Question 3

You have 28.7 g of Propanone (CH$_3$COCH$_3$) boiling in the lab. How many moles of vapor will be made if it is a gas? (Molar mass = 58.1 g/mol)

Accepted Answer

$0.494$ mol

Question 4

Which of the following solids is classified as an ionic solid?

Accepted Answer

K$_2$O

Question 5

A solution containing the equilibrium amount of solute is called:

Accepted Answer

A saturated solution

Question 6

Choose the correct order of increasing band gap for the following materials:

Accepted Answer

Conductor < Semiconductor < Insulator

Question 7

Which of the following molecules has the lowest Van’t Hoff factor?

Accepted Answer

C$_6$H$_{12}$O$_6$

Question 8

If you have a body-centered cube with a volume of $3.42 	imes 10^{-23}$ cm$^3$, what is the radius in picometers?

Accepted Answer

$1.52 	imes 10^3$ pm

Question 9

Which substance will have the highest viscosity at a given temperature?

Accepted Answer

CH$_3$CH$_2$OH

Question 10

Which would you expect to have the largest band gap?

Accepted Answer

SiO$_2$

Question 11

What is the phase change that occurs from B to C in the heating curve for water?

Accepted Answer

Vaporization

Question 12

Which of the following statements is FALSE regarding colligative properties?

Accepted Answer

Adding a solute to a solvent generally increases the vapor pressure

Question 13

Calculate the vapor pressure at 25°C of a solution containing 99.8 g sucrose (C$_{12}$H$_{22}$O$_{11}$) and 100.0 g water. The vapor pressure of pure water at 25°C is 23.8 torr. Assume the density of water is 1.00 g/mL.

Accepted Answer

$23.2$ torr

Question 14

Which compound is most soluble in water (H$_2$O)?

Accepted Answer

NH$_3$

Question 15

Sodium hydroxide (NaOH) dissolves in water. Is this process exothermic or endothermic if $\Delta H_{	ext{solution}} = 100$ and $\Delta H_{	ext{lattice energy}} = 25$?

Accepted Answer

Endothermic

Question 16

Determine the vapor pressure (in torr) of a substance at 15°C, whose normal boiling point is 90°C and has a $\Delta H_{	ext{vap}}$ of 41 kJ/mol.

Accepted Answer

$0.52$ torr

Question 17

A solution contains 3.87 g of an unknown protein per 100 mL of solution at 25°C and has an osmotic pressure of 2.43 atm. Find the molar mass of the unknown protein. ($R = 0.0821$ L·atm·mol$^{-1}$·K$^{-1}$)

Accepted Answer

$3870$ g/mol

CHM2046 Exam 1 Review: Intermolecular Forces, Solutions, and Phase Changes

Study Guide - Practice Questions

Study Guide - Flashcards