Unit 4 Chapters 10 and 11

Chapter 10: Gases

The Gas Laws

The Ideal Gas Law

Gas Density and Molar Mass

Volumes of Gases in Chemical Reactions

Mixtures of Gases and Partial Pressure

Collecting Gases Over Water

Example Prpoblems What volume will 2.5 moles of N 2 occupy at 45 o C and 1.5 atm? a) 43.5 L b) 6.08 L c) L d) L e) 14.9 L

If ideal gas behavior is assumed, what is the density of neon at STP? a) 1.11 g/L b) 448 g/L c) g/L d) 1.25 g/L

At 30.0 o C a sample of hydrogen is collected over water (P H2O = mm Hg at 30 o C) in a 500 mL flask. The total pressure in the collection flask is 745 mm Hg. What will be the percent error in the amount of hydrogen reported if the correction for the vapor pressure of water is not made? a) 0.0% b) + 4.5% c) - 4.5% d) + 4.3% e) - 4.3%

A gas mixture contains twice as many moles of O 2 as N 2. Addition of mol of argon to this mixture increases the pressure from 0.8 atm to 1.1 atm. How many moles of O 2 are in the mixture. a) b) c) d) e) 0.075

What volume of hydrogen gas, at STP, will a gram sample of magnesium (molar mass = g/mol) produce when reacted with excess HCl? a) 92.1 mL b) 46.1 mL c) 184 mL d) 9.2 mL e) 4.6 mL

Kinetic-Molecular Theory

Real Gases: Deviations from the Ideal Gas Law

Van der Waals

If 1.0 mol of an ideal gas were confined to 22.4 L at 0.0 o C it would have a pressure of 1.0 atm. Use the van der waals equation to estimate the pressure exerted by 1.0 mol of Cl 2 (g) in 22.4 L at 0.0 o C.

Chapter 11: Intermolecular Forces, Liquids and Solids

Intermolecular Forces

Properties of Liquids

Phase Changes

Vapor Pressure

Phase Diagram

Bonding in Solids

Example Questions Which of the following is expected to have the highest boiling point based on the strength of intermolecular forces? (A) Xe (B) Br 2 (C) Cl 2 (D) N 2 (E) O 2

Questions 26 – 32 refer to the following gases at 0 o C and 1 atim. (A) He (molar mass 4) (B) Xe (131) (C) O 2 (32) (D) CO 2 (44) (E) CO (28) 26.) Has the greatest density 27.) The particles of this gas have an average speed closest to that of N 2 molecuels at STP. 28.) Has the greatest rate of effusion. 29.) Has the lowest rate of effusion. 30.) Requires the lowest temperature and highest pressure to liquefy. 31.) The gas that has the greatest London dispersion forces. 32.) The gas that condenses at the highest temperature at 10 atim.

Sample Free Response Zinc reacts with Hydrochloric acid to produce hydrogen gas. How many milliliters of 1.5 M HCl are needed to react with excess zinc to produce 10 mL of hydrogen gas collected over water at 30 0 C and a total pressure of 750 torr.

C(sol)M.P.ΔH fus C(liq)B.P.ΔH vap C(gas) H2OH2O