Notes, summaries, assignments, exams, and exercises for Chemistry for Other courses

Chemist Concept of Free Energy

Derivation of the Van't Hoff Isochore Equation

To discuss the Van't Hoff Isochore Equation, we begin with the equation for the Van't Hoff isotherm:

ΔG° = -RT ln K_p (1)

By differentiating equation (1) with respect to temperature (T) at constant pressure (p):

[∂(ΔG°) / ∂T]_p = -R ln K_p - RT [d(ln K_p) / dT]_p (2)

Multiply equation (2) by T:

T [∂(ΔG°) / ∂T]_p = -RT ln K_p - RT² [d(ln K_p) / dT]_p

Since ΔG° = -RT ln K_p, we can substitute this into the equation:

T [∂(ΔG°) / ∂T]_p = ΔG° - RT² [d ln K_p / dT] (3)

Therefore: ΔG° - T [∂(ΔG°) / ∂T]_p = RT² [d ln K_p / dT]

Integration with the Gibbs-Helmholtz Equation

Now, the Gibbs-Helmholtz equation at standard state is:

ΔG° = ΔH° + T [∂(ΔG°) / ∂T]_p

ΔH°...

1. Gold Extraction

   Gold is found mainly as the metal itself in the earth because it has a low reaction rate, which prevents easy oxidation.

Carbon Extraction of Zinc

Carbon can be used to extract zinc because carbon has a higher reaction rate than zinc.

Sodium Extraction

Sodium was not extracted until 1807 because sodium attaches itself very strongly to other elements, making it difficult to separate and obtain a pure substance.

Limestone

i) Name of Material: Limestone

Reason why this metal is used: It decomposes silicon dioxide in the heat of the furnace to calcium oxide.

ii) Word Chemical Equation for the Reaction of Iron Extracted from Iron Ore when a Gaseous Oxide of Carbon Reacts with Iron Oxide: FeO + CO = Fe + CO2

Aluminium Extraction

i) Why a Mixture...

Recognition of Lipids

Laboratory Materials

• Test tubes
• Rack
• Glass rods
• Lighter
• Beakers
• Pipettes
• 20% NaOH solution
• Sudan III solution
• Red ink
• Ether, chloroform, or acetone
• Olive oil

2.1 Saponification

Basis

Hot fat reacts with sodium or potassium hydroxide, decomposing into two elements: glycerol and fatty acids. These ions combine with the hydroxide to produce soaps, which are sodium or potassium salts of fatty acids. In living organisms, the hydrolysis of triglycerides is facilitated by specific enzymes called lipases, which form fatty acids and glycerol.

Technique

1. Place 2ml of oil and 2ml of 20% NaOH in a test tube.
2. Shake vigorously and place the tube in a water bath for 20 to 30 minutes.
3. Afterward, three phases will be visible in the tube: a clear bottom layer

Understanding Atomic Structure

Atomic Number

The atomic number (Z) is the number of protons in an atom. In a neutral atom, the number of electrons is equal to the number of protons.

Mass Number

The mass number (A) of an atom is the total number of protons (Z) and neutrons (n) in the nucleus. Therefore, A = Z + n.

Atomic Mass

The atomic mass is the mass of a single atom. Because the masses of atoms are very small, they are typically expressed using atomic mass units (amu) rather than SI units.

Isotopes

Isotopes are atoms of the same element that have the same atomic number but different mass numbers. Isotopes of an element have the same number of protons but different numbers of neutrons.

Atomic Orbitals (Electron Shells)

Atomic orbitals, or electron...

Material Structure and Properties

Inter-Atomic Bonding

Different materials are made up of different types of bonds. The following are examples and characteristics of the chemical bonds that make up materials.

• Ionic Bonding
  

  Ionic bonding in NaCl. Callister, W. D., & Rethwisch, D. G. (2018). Materials Science and Engineering: An Introduction.

  • Description: Found in compounds composed of metallic and nonmetallic elements; involves atoms at the extremes of the periodic table.
  • Process: Metallic atoms give up their valence electrons to nonmetallic atoms; atoms achieve stable inert gas configurations (filled orbital shells) and acquire electrical charges (become ions).
  • Example: Sodium chloride (NaCl) is a classic ionic material; a sodium atom transfers

Spaghetti Carbonara

Utensils and Ingredients

Utensils

• Large pot
• Large skillet
• Colander
• Large bowl
• Whisk or fork
• Tongs or a pasta fork
• Spoon or ladle

Ingredients:

• 400g spaghetti
• 200g pancetta or bacon, diced
• 4 large eggs
• 1 cup grated Parmesan cheese
• 4 cloves garlic, minced
• Salt and black pepper to taste
• 2 tablespoons olive oil
• Chopped parsley for garnish (optional)

Instructions

1.

Boil the Spaghetti

Start by boiling a large pot of salted water. While waiting, dice the pancetta, mince the garlic, and grate the Parmesan cheese.

2.

Cook the Spaghetti

Once the water boils, add the spaghetti and cook until al dente. Once cooked, reserve about a cup of pasta water before draining.

3.

Sauté the Pancetta and Garlic

In a large skillet, heat the olive oil over medium heat. Add...

Experiment 1: Strength of Hydrochloric Acid

Aim

To determine the strength of the given dilute hydrochloric acid (HCl) solution by titrating it against a standard sodium carbonate (Na₂CO₃) solution.

Chemicals Required

• Standard sodium carbonate (Na₂CO₃) solution
• Dilute hydrochloric acid (HCl) solution
• Methyl orange indicator

Apparatus Required

• Burette
• Burette stand
• Pipette
• Conical flask
• Funnel

Chemical Reaction

Na₂CO₃ + 2HCl → 2NaCl + H₂O + CO₂

Principle

Normality is defined as the number of gram equivalents of solute present in one litre of solution. According to the law of equivalence, the relationship between the reacting solutions is given by:

N₁V₁ = N₂V₂

Where:
N₁ - Normality of HCl (unknown)
V₁ - Volume of HCl used
N₂ - Normality...

1.Who propossed the theory of One-dimensional consolidation? Karl Terzaghi

2.What types of permeameters exist in Lab tests? Constant head permeameter and Failing head permeameter

3.What is the name of the equation that Governs the 2D underground flow? Laplace’s Equation.

4.Name of the method of draw flow nets That uses iterative calculations. Finite Differences

5.What are the units of the compression Index Cc? Adimensional, NOT UNITS

6.Describe boiling in soils. Boiling of soils occurs when there is an Upward flow and the seepage force is greater that the submerged weight of the Soil.

7.What are the assumptions in laplace’s Equation. Darcy’s law applies, Water and Solids are uncompressible

8.When in it better to use failing head permeameter?

Zinc Concentrate Roasting Process: 850 T/day Capacity

Blende-Roasting Furnace and Heat Recovery Steam Generator

This includes the furnace that carries out the oxidation of ZnS, the heat recovery steam generator for cooling the gas, and the partial removal of solids carried by the gases.

Treatment Water for Steam-Water Circuit

This is the demineralized process water. This water will be used in the heat recovery boiler and furnace beams, which form part of the same circuit.

Purification of Gases from Roasting

The functions of the gas produced are to eliminate impurities and reduce the gas temperature for treatment.

Contact and Absorption

This is the transformation of SO₂ into sulfuric acid for reuse in marketing or the leaching stage.

Feedstock and Products

This...

Understanding Carbohydrates

Carbohydrates are biomolecules primarily composed of carbon, hydrogen, and oxygen. Their atoms are linked to alcohol groups (hydroxyl groups, -OH) and hydrogen atoms (-H). All carbohydrates contain a carbonyl group (C=O), which can be either an aldehyde group (-CHO) or a ketone group (-CO). Therefore, they can be defined as polyhydroxyaldehydes or polyhydroxyketones.

Classification of Carbohydrates

Carbohydrates are classified into several groups:

• Monosaccharides: Simple sugars made of single units.
• Oligosaccharides: Contain between 2 and 10 monosaccharide units.
• Polysaccharides: Formed by multiple repeating units of monosaccharides, further divided into:
  • Homopolysaccharides: Formed by the repetition of a single monomer.