Notes, summaries, assignments, exams, and problems for Chemistry

Q#9.1: How order of reaction is experimentally determined.

Ans. Order of reaction is determined by the following two methods.

1. From Rate Law.

   In this method, the rate of reaction is measured using chemical and physical methods (volumetric, gravimetric, spectrophotometer, pH-meter, conductometric methods). The dependence of the rate of reaction on the concentration of reactants tells us about the order of reaction. For example, a reaction in which the rate of reaction doubles when the concentration of reactants is doubled will be of first order. If the rate increases four times by doubling the concentration, the reaction will be of second order.

2. Ostwald’s Isolation Or Large Excess Method.

   This method is used to determine the order of complicated

Questions

Answers

Why do you use distilled water in your experiments?

Because distilled water has all its impurities removed through distillation.

What is the formula for converting oC to Fahrenheit( F)?

(oC x 1.8) + 32

Formula for converting oF into Celsius

 (oF - 32)  1.8

Formula for converting oC to Kelvin(K)

K = oC + 273.15

Name all the volumetric apparatus used in the lab

Beaker, measuring cylinder, Burette, Pipet, and volumetric flask. (See the attachment)

A student got the following results in his experiment: 14.9g, 14.19g, 14.88g, 14.92g, but the actual weight is 20.90g. How accurate are the student results. And how precise are the results.

The student results are not accurate but precise. Has the precision of  0.05g

Sketch 2 pieces of glassware:

Kinetic Energy and the Nature of Matter

• Kinetic Energy: The energy an object possesses due to its motion.
• Kinetic Theory: States that all matter is composed of tiny particles in constant motion.

Pressure and Its Measurement

• Gas Pressure: Results from the force exerted by a gas per unit surface area of an object.
• Vacuum: An empty space devoid of particles and pressure.
• Atmospheric Pressure: Arises from the collisions of atoms and molecules in the air with objects.
• Barometer: A device used to measure atmospheric pressure.
• Pascal (Pa): The SI unit of pressure.
• Standard Atmosphere (atm): The pressure required to support 760 mm of mercury in a mercury barometer at 25ºC.

Phase Transitions and States of Matter

• Vaporization: The conversion of a liquid to a gas

Impact of Minimum CD & Treasury Bond Investment

Question: If the amount invested in CDs and treasury bonds is at least $5,000 plus 1.2 times the amount invested in municipal bonds and growth stocks, what is the new optimal solution and Optimal Feasible Value (OFV)?

Answer: Since the allowable increase is greater than $5,000 and this is a binding constraint, you must re-solve the problem to obtain the new optimal solution. The new OFV can be estimated using the shadow price: New OFV ≈ Old OFV + 5000 * (-0.0295).

Adding a GIC Investment Alternative

Question: If there is another investment alternative in Guaranteed Investment Certificates (GICs) with a Return on Investment (ROI) of 10%, what is the new optimal solution and OFV?

Answer: Introducing... Continue reading "Investment Portfolio Optimization: Sensitivity Analysis" »

The Sun: Structure and Activity

Galileo's Solar Observations

Galileo Galilei was among the first scientists to study the Sun in detail (circa 1610).

Sun's Chemical Makeup

The Sun's composition is primarily Helium & Hydrogen.

Inside the Sun

Solar Atmosphere Layers

• Photosphere
• Chromosphere
• Corona

Solar Interior Zones

• Core
• Radiative Zone
• Convective Zone

How the Sun Produces Energy

Solar energy is produced by nuclear fusion in the core region, converting hydrogen into helium. This process is the source of the Sun's energy.

The energy output is approximately 9 × 10¹⁰ megatons of TNT per second.

Understanding Solar Wind

Solar Wind is solar material flowing into interplanetary space. The Sun's atmosphere is expanding radially outwards in all directions. Solar... Continue reading "Science Essentials: Sun, Matter, Physics" »

How Solutions are Formed

The particles that make up a solution are in constant movement: they move faster as they go from solid state to liquid state. This happens until we obtain a homogeneous system where all its parts have the same properties. This movement is responsible for them mixing together.

Types of Solutions

Gaseous Solutions

The most important is air.

Liquid Solutions

The most important liquid solutions are those that involve water. When the forces with which the water molecules attract the molecules of the solid are greater than the forces acting between them, the particles separate and form the solution.

Solid Solutions

Alloys are mixtures of metals obtained by mixing together the melted components.

Diluted Solution: Amount of solute small... Continue reading "Formation of Solutions: Types and Properties" »

Indian Classical Music Quiz

a) How many kinds of ‘Graha’ are there?

1. 1
2. 2
3. 3
4. 4

(अ). ग्रह के ककतने प्रकार है (i) 1 (ii) 2 (iii) 3 (iv) 4

b) Minimum avartan of ‘Paran’ are:-

1. 4
2. 5
3. 2
4. 1

(ब) ऩरण कम से कम ककतने आवतनय का होता है (i) 4 (ii) 5 (iii) 2 (iv) 1

c) 4 5 6 indicates the Tala Dha Tu Na 0

1. Dadra
2. Keharwa
3. Rupak
4. Dhamar

स)) 4 5 6 ककस ताऱ का दशायता है्- धा तू ना 0 (i) दादरा (ii) कहरवा (iii) रुऩक (iv) धमार

d) How many kinds of ‘Jatti’ are there?

1. 3
2. 4
3. 5
4. 6

(द) िानत के ककतने प्रकार हैं? (i) 3 (ii) 4 (iii) 5 (iv) 6

e) Laggi is used in :-

1. Khyal
2. Dhrupad
3. Bhajan
4. Dhamar

य)... Continue reading "Indian Classical Music Quiz: Graha, Paran, Tala, and Jatti" »

Nucleus: The Center of an Atom

The nucleus is located at the center of an atom. It is very small and has a positive electrical charge due to the protons. The nucleus contains particles called protons and neutrons, which make up nearly all of the atom's mass.

Electron Cloud: The External Area of an Atom

The electron cloud surrounds the nucleus and is longer than the nucleus. It has an equal but negative electrical charge compared to the protons. The electron cloud contains particles called electrons, and their mass is negligible compared to the protons and neutrons.

Historical Development of Atomic Structure

In the 5th century, ancient Greeks proposed the concept of the atom. In 1808, Dalton discovered the existence of protons and electrons. In 1904,... Continue reading "Atomic Structure and Chemical Reactions: A Comprehensive Overview" »