Chemistry 1411 Exam Notes

HOUSTON COMMUNITY COLLEGE - CHEMISTRY 1411 EXAM NOTES

TABLE OF CONTENTS

  • The Periodic Table of Chemical Elements

  • Exam Sample Questions

    • Part I: Multiple Choice Questions

    • Part II: Show all Work

  • Exam Keys

THE PERIODIC TABLE OF CHEMICAL ELEMENTS

  • The

    • Details on elements and their symbols and atomic numbers, covering main groups, lanthanides, and actinides.

  • Elements are listed with their respective symbols (e.g., H for Hydrogen, He for Helium).

Major Elements on the Periodic Table

  • 1-10:

    1. H (Hydrogen)

    2. He (Helium)

    3. Li (Lithium)

    4. Be (Beryllium)

    5. B (Boron)

    6. C (Carbon)

    7. N (Nitrogen)

    8. O (Oxygen)

    9. F (Fluorine)

    10. Ne (Neon)

Lanthanides and Actinides

  • Lanthanides include elements from La to Lu.

  • Actinides include elements from Ac to Lr.

EXAM SAMPLE QUESTIONS

Part I: Multiple Choice Questions

  • Each question is worth 4 points.

  • Students must choose the correct answer from the options provided.

Sample Questions

  1. The distance between carbon atoms in ethylene is 134 picometers. Which of the following expresses the distance in meters?

    • A. 1.34x10⁻¹³ m

    • B. 1.34x10⁻¹⁰ m

    • C. 1.34x10⁻⁷ m

    • D. 1.34x10⁻⁶ m

    • Correct Answer: B

    • Explanation: (134extpm=134imes10−12m=1.34imes10−10m)(134 ext{ pm} = 134 imes 10^{-12} m = 1.34 imes 10^{-10} m)

  2. Acetic acid boils at 244.2 °F. What is its boiling point in degrees Celsius?

    • A. 167.7 °C

    • B. 153.4 °C

    • C. 117.8 °C

    • D. 103.7 °C

    • Correct Answer: C

    • Formula: (C=rac59(F−32))(C = rac{5}{9}(F-32))

    • Calculation:
      C=rac59(244.2−32)=rac59(212.2)=117.9°CC = rac{5}{9}(244.2-32) = rac{5}{9}(212.2) = 117.9 °C

  3. Measurement of 52,030.2 m in scientific notation?

    • A. 5.20302x10⁴ m

    • B. 5.203x10⁴ m

    • C. 5.20x10⁴ m

    • D. 5.2x10⁴ m

    • Correct Answer: A

  4. Correct number of decimal places for the sum: 4.65 g + 2.0 g + 19.6442 g?

    • A. 26.2942 g

    • B. 26.29 g

    • C. 26 g

    • D. 26.3 g

    • Correct Answer: D

    • Explanation: Round off the sum to the least number of decimal points (one).

Part II: Show All Work for Complete Credit

  • Each question is worth 8 points.

Example Problem

  1. Density of mercury:

  • Density: (ext13.6g/cm3)( ext{13.6 g/cm}^3)

  • Convert to pounds per cubic inch.
    extDensityinlb/in3=(rac13.6extg/cm3454extg/lb)imes(rac(2.54extcm)31extin3)=0.491extlb/in3ext{Density in lb/in}^3 = ( rac{13.6 ext{ g/cm}^3}{454 ext{ g/lb}}) imes ( rac{(2.54 ext{ cm})^3}{1 ext{ in}^3}) = 0.491 ext{ lb/in}^3

EXAM KEYS

  • Answers to the sample questions categorized into Part I and Part II, outlining correct answers with a description of calculations and reasoning for each question to support student learning.

Part I Key

  1. B

  2. C

  3. A

  4. D

Part II Key

  1. Density calculations shown. 17-25. Solutions detailing methodology for determining moles, molecular weights, and conversion processes.

    • Example: Determining limiting reactant in chemical reactions, empirical formulas from combustion analysis data, and necessary calculations based on formula weights.

Additional Reference Sections

CONVERSIONS AND FORMULAS

  • Useful information related to conversions between units and key formulas that students may require:

    • Conversions: 1 lb = 454 g, 1 in = 2.54 cm

    • Density formula: Density = mass/volume

    • Temperature conversions among Celsius, Fahrenheit, and Kelvin.

This structured representation of material provides an extensive resource for exam preparation in Chemistry 1411, ensuring comprehensive understanding and review of relevant concepts, calculations, and chemical principles.