CHEM 120 Week 7 Review Quiz: Key Concepts and Questions

CHEM 120 Week 7 Review Quiz: Key Concepts and Questions

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Chamberlain University

CHEM-120 Intro to General, Organic & Biological Chemistry

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Week 7 Review Quiz

Redox Reactions and Electron Transfer

When an atom gives away electrons during a redox reaction, it is undergoing oxidation. In such processes, the loss of electrons defines the atom as oxidized.

Identifying Reduced Elements in Reactions

In the redox reaction involving chromium oxide and hydrogen, specifically: CrO + H₂ → H₂O + Cr, chromium (Cr) is the element undergoing reduction, as it gains electrons during the process.

Role of Oxidizing Agents

In a redox scenario involving iron and vanadium—Fe³⁺ + V → Fe + V³⁺—the oxidizing agent is Fe³⁺. This is because Fe³⁺ accepts electrons and facilitates the oxidation of vanadium.

Hydrocarbons and Functional Groups

Among common molecules, methanol does not qualify as a hydrocarbon due to the presence of an -OH (hydroxyl) group. Hydrocarbons are defined solely by hydrogen and carbon atoms.

Molecules with Triple Bonds

Compounds such as pentyne and butyne are known to contain carbon-carbon triple bonds, which makes them alkynes, a class of hydrocarbons with higher unsaturation.

Applications of Hydrocarbons

Hydrocarbons serve as a primary energy source and are widely used as fuels in transportation and energy industries due to their combustibility.

Identifying Functional Groups

The -COOH grouping in organic molecules represents the carboxyl functional group, commonly found in carboxylic acids.

Types of Hydrocarbons

Hydrocarbons featuring double bonds between carbon atoms are classified as alkenes. These compounds are considered unsaturated because they do not have the maximum number of hydrogen atoms.

Unsaturated Hydrocarbons

Examples of unsaturated hydrocarbons include molecules like CH₂=CH₂ (ethene) and propyne. These compounds contain either double or triple carbon-carbon bonds.

Naming Organic Compounds

The IUPAC name for CH₃CH₂OCH₃ is ethyl methyl ether, indicating an ether functional group bridging two different alkyl groups.

Matching Organic Formulas and Names

Matching chemical formulas with their respective names is essential in organic chemistry for correct compound identification and nomenclature.

Radioactive Decay Products

When molybdenum-99 undergoes beta decay, it emits an electron and transforms into technetium-99. This is a common decay pathway used in medical imaging.

Electron Capture and Mass Numbers

Tin-126 undergoing electron capture results in no change in mass number; thus, the product retains a mass number of 126.

Sources of Electromagnetic Radiation

Both X-ray emitters and gamma decay processes are sources of electromagnetic radiation, contributing to both diagnostic and natural background radiation.

Half-Life Calculations

If a radioactive substance has a half-life of 10 minutes, then three half-lives would pass in 30 minutes. This concept is crucial for determining decay rates.

Radioactive Decay and Remaining Mass

Starting with a 60g sample with a 5-year half-life, only 15g would remain after 10 years. This calculation applies the formula for exponential decay.

Positron Emission Products

When polonium-255 emits a positron during decay, the resulting element is bismuth-255. This reflects a decrease in atomic number due to the positron emission.

Identifying Protein Examples

Proteins such as enzymes and antibodies play vital roles in biological systems. Enzymes act as catalysts, while antibodies participate in immune responses.

Classification of Carbohydrates

Among carbohydrates, starch is categorized as a polysaccharide, composed of long chains of glucose molecules. It functions as an energy reserve in plants.

Fatty Ester Formation

Fatty acids and glycerol are involved in forming fatty esters. These are the building blocks of lipids such as triglycerides.

Characteristics of Fats

Lipids classified as fats are typically solid at room temperature and do not contain double bonds between carbon atoms, meaning they are saturated fats.

DNA Template Strand Coding

Given a coding DNA strand sequence of TAC-CGAGAC-TAG, the complementary template strand would be ATG-GCT-CTG-ATC, adhering to base pairing rules.

Biomolecules in Transcription

The transcription process involves both mRNA and DNA. mRNA carries the genetic code transcribed from DNA to the ribosome for protein synthesis.

Protein Synthesis Process

The translation process refers to synthesizing proteins from mRNA at the ribosomes. This is the second stage of gene expression following transcription.

Macromolecule Categories

Fats and oils are classified under the lipid category of biological macromolecules. These molecules serve as long-term energy storage and structural components.

Protein Structure Levels

The quaternary structure of a protein is defined by the interaction and arrangement of multiple polypeptide chains, contributing to the protein’s functionality.

Function of Enzymes

Enzymes act as biological catalysts, speeding up chemical reactions in the body without being consumed in the process. They are essential for metabolism and homeostasis.

References

OpenStax. (2016). Chemistry. OpenStax CNX. https://cnx.org/contents/85abf193-2bd…/Chemistry

Brown, T. L., LeMay, H. E., Bursten, B. E., Murphy, C., & Woodward, P. (2018). Chemistry: The Central Science (14th ed.). Pearson.

CHEM 120 Week 7 Review Quiz: Key Concepts and Questions

Timberlake, K. (2018). Chemistry: An Introduction to General, Organic, and Biological Chemistry (13th ed.). Pearson.