Chemistry Concepts: Chapters 4, 5, and 7 Overview

Posted by on Aug 27, 2024 in Chemistry | 0 comments

Chapter 4: Reactions in Aqueous Solutions

Key Concepts:

  • Electrolytes:
    • Argon (Ar) is not an electrolyte.
    • A strong electrolyte ionizes completely in solution.
    • A weak electrolyte exists predominantly as molecules in solution.
  • Reactions:
    • Aqueous potassium chloride will react with lead nitrate in an exchange (metathesis) reaction.
    • Zinc sulfide (ZnS) is insoluble in water.
    • A neutralization reaction between an acid and a metal hydroxide produces water and a salt.
    • Oxidation cannot occur without reduction.
  • Acids and
Read More

Stoichiometry and Thermochemistry MCQ Practice with Answers

Posted by on Aug 26, 2024 in Chemistry | 0 comments

Topic 1: Stoichiometry

Questions and Answers

1. What amount of oxygen, O2, (in moles) contains 1.8×1022 molecules?

B. 0.030

2. Which compound has the empirical formula with the greatest mass?

B. C4H10

3. __C2H2(g) + __O2(g) → __ CO2(g) + __ H2O(g)

When the equation above is balanced, what is the coefficient for oxygen?

D. 5

4. 3.0 dm3 of sulfur dioxide is reacted with 2.0 dm3 of oxygen according to the equation below.

2SO2(g) + O2(g) → 2SO3(g)

What volume of sulfur trioxide (in dm3) is formed? (Assume

Read More

Organic Chemistry Key Concepts & Reactions

Posted by on Aug 26, 2024 in Chemistry | 0 comments

Organic Chemistry: Key Concepts & Reactions

Benzene & Its Derivatives

Structure & Stability of Benzene

Benzene is a cyclic, planar molecule with six carbon atoms. Each carbon atom is bonded to two other carbon atoms and one hydrogen atom via single covalent sigma bonds, resulting in a trigonal planar geometry with bond angles of 120 degrees. This leaves one unused electron on each carbon atom in a p-orbital perpendicular to the plane of the ring. These p-orbitals overlap with neighboring

Read More

Winemaking Techniques: Tartaric Stabilization, Malolactic Fermentation & More

Posted by on Aug 26, 2024 in Chemistry | 0 comments

5 Tartaric Stabilization Treatments in Wine

The treatment of tartaric stabilization of wine commonly used are:

  1. Chemicals: This involves the use of additives that inhibit the formation of crystals. Among the chemicals used is mesotartaric acid, a polymer of tartaric acid obtained by heating tartaric acid at 170°C. It is added to wine and wraps the crystals of tartrate, preventing them from growing. However, this action only lasts nine months as it is hydrolyzed in the wine and transformed back into
Read More

Sparkling Wine Production and Protein Stability in Wine

Posted by on Aug 26, 2024 in Chemistry | 0 comments

Protein Stability in Wine

Protein Bankruptcy

Protein bankruptcy occurs when grape proteins and yeast in wine coagulate due to heat, cold, or tannins from oak aging or cork stoppers. This results in a haze that starts below the cap and spreads throughout the bottle when agitated. Red wines are less susceptible due to tannins binding with proteins during barrel aging. White wines, however, retain proteins that need removal before bottling.

Treatment

Bentonite, a negatively charged clay, is used to remove

Read More

A Comprehensive Guide to Chemical Bonds, Crystal Structures, and Alloys

Posted by on Aug 23, 2024 in Chemistry | 0 comments

Ionic Bond

An ionic bond occurs between metals and nonmetals. It is formed by the electrostatic attraction between oppositely charged ions.

Covalent Bond

A covalent bond forms between non-metallic elements. Covalent bonds can be single, double, or triple.

Ionic Compounds

Ionic compounds are characterized by the following properties:

  • Hard
  • High melting and boiling points
  • Soluble in polar solvents
  • Conduct electricity in a dissolved or molten state
  • Brittle

Metallic Compounds

Metallic compounds exhibit these properties:

Read More