Chemistry Form 4: Chapter 7 - Determining the Molarity of Acid and Base Using Titration

Click on the diagram below to play!

Click on the diagram below to play!

Earth Scenic From International Space Station

A time-lapse taken from the front of the International Space Station as it orbits our planet at night. This movie begins over the Pacific Ocean and continues over North and South America before entering daylight near Antarctica. Visible cities, countries and landmarks include (in order) Vancouver Island, Victoria, Vancouver, Seattle, Portland, San Francisco, Los Angeles. Phoenix. Multiple cities in Texas, New Mexico and Mexico. Mexico City, the Gulf of Mexico, the Yucatan Peninsula, El Salvador, Lightning in the Pacific Ocean, Guatemala, Panama, Columbia, Ecuador, Peru, Chile, Lake Titicaca, and the Amazon. Also visible is the earths ionosphere (thin yellow line), a satellite (55sec) and the stars of our galaxy.

In the beginning God created the heavens and the earth. 2Now the earth was^a formless and empty, darkness was over the surface of the deep, and the Spirit of God was hovering over the waters. 3And God said, “Let there be light,” and there was light. 4God saw that the light was good, and he separated the light from the darkness. 5God called the light “day,” and the darkness he called “night.” And there was evening, and there was morning—the first day

........second day........third day ...........fourth day..................fifth day.................On sixth day.......... 

Then God said, “Let us make man in our image, in our likeness, and let them rule over the fish of the sea and the birds of the air, over the livestock, over all the earth,^b and over all the creatures that move along the ground.”27So God created man in his own image, in the image of God he created him; male and female he created them. 28God blessed them and said to them, “Be fruitful and increase in number; fill the earth and subdue it. Rule over the fish of the sea and the birds of the air and over every living creature that moves on the ground.”

Physics Form 4: Chapter 4 - Charles's Law of Gas

Charles's law states that for a fixed mass of ideal gas, the volume is directly proportional to its absolute temperature at constant pressure.

Explanation of Charles law by the kinetic theory

·         When the temperature of a gas in an enclosed cylinder is raised, the gas molecules receive heat energy and their average kinetic energy increases. ·         This means that molecular velocity will increase and the frequency of collision between the molecules and the wall of the cylinder also increases. Thus, the gas pressure increases. ·         Increase in pressure will cause the piston to be pushed up and this indicates that the volume of the gas has increased.

Click on the diagram below to play!

Chemistry Form 4: Chapter 7 - Neutralization Reaction

As you can see from the equations, acids release H⁺ into solution and bases release OH^-. If we were to mix an acid and base together, the H⁺ ion would combine with the OH^- ion to make the molecule H₂O, or plain water:

H+(aq)

+

OH-(aq)

H2O

Neutralization is a reaction between acid and base to produce salt and water only as shown below:

Acid		Base		Water		Salt
HCl	+	NaOH		H2O	+	NaCl
HBr	+	KOH		H2O	+	KBr

Uses of neutralization

1. Soil treatment - if the soil is too acidic, it is treated with a base in order to neutralise it. Common treatments use quicklime (calcium oxide) or chalk (calcium carbonate). 
2. Indigestion -  too much hydrochloric acid in our stomach leads to indigestion. Therefore, to cure this ailment we need to neutralise the acid with a base such as, sodium hydrogen carbonate (baking soda), or milk of magnesia. 
3. Bee sting contains acid -  In order to relieve the painful symptoms of the sting we need to neutralise the acid. By rubbing on calamine lotion (zinc carbonate) or baking soda the acid can be neutralised.
4. Wasp sting contains alkaline -  Hence acid is needed to neutralise and remove the painful sting. Vinegar (ethanoic acid) is used.

Physics Form 5: Chapter 5 - Einstein Equation, Mass-Energy Equivalence

In 1905, Albert Einstein published his theory of Special Relativity. In this paper, Einstein took his readers through the thought process which led him to the most famous equation, E = mc².

Introduction to mass and energy
Mass is a measurement of how much quantity of matter inside of an object. Mass is also a measure of inertia - the more mass an object has, the harder it is to move and once it is moving, the harder it is to stop it. On the hand, energy is the ability to do work. Mass and energy can be neither created nor destroyed. While they can be converted into different forms (mass can turn from solid to liquid to gas, and can be cut up or turned to dust, while kinetic energy can be transferred to potential energy or sound energy or heat energy), there will always remain the same amount in our universe.

Einstein's way to explain mass and energy

Einstein began, it is said, by looking at the equation for finding an object’s kinetic energy:

Einstein was able to take this equation, combine it with other known equations, do a little bit of math, and come up with the following:

 

The equation most people are familiar with, E = mc², can be obtained by assuming that the “object” in question has a speed of zero. If an object is perfectly still, the entire right half of the equation cancels out, and we are only left with the familiar equation.

This equation shows that Mass and Energy are not just similar – they are the same thing, but in different forms, with the ability to be converted into one another. Mass can be turned into energy, and energy can be turned into mass. Further, this equation shows us that a tiny bit of mass can be turned into a lot of energy (the equivalent of the amount of mass times the speed of light squared!), while a lot of energy can only be turned into a little bit of mass.

The equation truly was a revolutionary one, though no one knew just how much so until it was realized that it would be possible, using radioactive elements, the atomic bomb, and later atomic energy.

It is Einstein’s equation which helped scientists predict just what would happen when that first nuclear explosion was triggered, and it is what tells particle physicists what will happen when they smash two beams of particles together in an accelerator.

Physics Form 4: Chapter 4 - Absolute Temperature

• Temperature is a measure of the average kinetic energy of a system particles. When temperature rises, the average kinetic energy of particles also increases.
• Temperature is the degree of hotness, a measure of heat intensity.

Absolute temperature is based on the Kelvin scale. Units on the Kelvin scale are called Kelvins (K) and no degree symbol is used.

 

The concept of an absolute zero of temperature evolved in connection with experiments with gases. When a fixed mass of gas is cooled at a constant pressure (volume), its volume (pressure) decreases with its temperature. A plot of the experimental values of volume (pressure) versus temperature can be extrapolated to cross the temperature axis when the volume (pressure) would be zero. The temperature is the absolute zero of temperature. It is -273.15 °C, or more approximately -273 °C.

What happens to the matter at absolute zero temperature?

At absolute zero temperature, it's the point at which particles have a minimum energy. Near absolute zero, the matter stops acting the way it should and starts exhibiting some strange properties. Some types of matter become superconducting, carrying electric current with absolutely no resistance, and some of them, like helium, become superfluid at this temperature, exhibiting absolutely no friction, becoming a Bose-Einstein Condensate (BEC). This means that a droplet of superfluid helium can rotate inside a container forever, as if it were in a vacuum.

So far, this temperature has never been achieved, and in theory it could never be achieved. In 1994, the NIST achieved a record cold temperature of 700 nK (billionths of a kelvin). In 2003, researchers at MIT eclipsed this with a new record of 450 pK (0.45 nK).

This Is Called Life

人生何其短華髮換白頭

May all of you have abundant life 

Physics Form 5: Chapter 5 - Ionizing Power and Penetrating Power

Type of Radiation	Alpha particle	Beta particle	Gamma ray
Symbol	α	β	γ
Mass (atomic mass units)	4	1/2000	0
Charge	+2	-1	0
Speed	slow	fast	very fast (speed of light)
Ionising ability	high	medium	weak
Penetrating power	low	medium	high
Stopped by:	paper	aluminium	lead

Alpha particle:

• It carries +2 charge and exerts greater forces on the neighbouring air molecules.
• It moves at a relatively low speed. The chance of ionising the neighbouring molecule is higher.
• It has a strong ionising power and it loses kinetic energy readily to ionise the air molecules along its path. So it has absorbed in the air quickly.

Beta particle:

• It carries -1 charge and exerts smaller forces on the air molecules.
• It travels faster and the chances of ionising the neighbouring molecules are lower.
• It has much weaker ionising power. So it loses kinetic energy at lower rate. Thus, it has a stronger penetrating power than alpha.

Gamma particle:

• It is electrically neutral and travels very fast at the speed of light.
• Ionising effects only occur when they collide directly with the air molecules. Since the chances for such a collision are very slim, gamma rays seldom produce ion pairs.
• It is a high frequency electromagnetic wave and it possess the highest energy.
• It has extremely weak ionising power. So it loses kinetic energy at the lowest rate.