Reactions in Aqueous Solution

Precipitation Reaction

Precipitation occurs when ions in solution “swap partners” to form a new compound of low solubility in water. This low-solubility compound forms as solid particles that eventually settle which is called the "precipitate".

To predict whether a precipitate will form, you need to  know which substances are soluble in water and which  are insoluble.

Example.

These reactions are Double Displacement reactions, otherwise known at Metathesis Reactions, because the cations effectively change places. Here, the Pb2+ cation displaces the K+ cation and combines with the Iodide (I-) to form PbI2. Likewise, the K+ cation displaces the Pb2+ cation to combine with the Nitrate (NO3-) to form KNO3. 

Acid-base Reaction

An acid-base reaction is one in which an acid reacts with a base to form a salt and water.

Redox Reaction (Oxidation-Reduction Reaction) is a type of chemical reaction that involves a transfer of electrons between two species. Oxidation is the loss of electrons. Reduction is the gain of electons. Each reaction is called "half-reaction" simply because we need the two to have a whole reaction.

Precipitation and acid-base reactions are sometimes known as ion exchange reactions. Ion exchange reactions also include gas forming reactions. Ion exchange reactions are a type of reaction where the positive ions exchange their respective negative ions due to a driving force.

A number of tests can be used to identify whether certain anions (chlorides, bromides,

iodides, carbonates, sulphates) are present in a solution.

Redox Reaction is a class of reactions that include:

– formation of a compound from its elements

– all combustion reactions

– reactions that generate electricity

– reactions that produce cellular energy

Oxidizing agent is the species doing the oxidizing.

Reducing agent is the species doing the reducing.

Instantaneous Acceleration Sample Problem

1. The fastest measured pitched baseball left the pitcher’s hand at a speed of 45.0 m/s. If the pitcher was in contact with the ball over a distance of 1.50 m and produced constant acceleration, (a) what acceleration did he give the ball, and (b) how much time did it take him to pitch it?

Instantaneous Velocity Sample Problem

1. A car is stopped at a traffic light. It then travels along a straight road so that its distance from the light is given by  (a) x(t)=bt^2-ct^3, where b=2.40m/s^2 and c=0.120m/s^3.   Calculate the average velocity of the car for the time interval to (b) Calculate the instantaneous velocity of the car at and (c) How long after starting from rest is the car again at rest?
Answer:

Another awesome experiment.

Organic Chemistry

What is Organic Chemistry?

Organic chemistry is the branch of chemistry that deals with organic molecules. An organic molecule is one which contains carbon, and these molecules can range in size from simple molecules to complex structures containing thousands of atoms! Although carbon is present in all organic compounds, other elements such as hydrogen (H), oxygen (O), nitrogen (N), sulphur (S) and phosphorus (P) are also common in these molecules.

Until the early nineteenth century, chemists had managed to make many simple compounds in the laboratory, but were still unable to produce the complex molecules that they found in living organisms. It was around this time that a Swedish chemist called Jons Jakob Berzelius suggested that compounds found only in living organisms (the organic compounds) should be grouped separately from those found in the non-living world (the inorganic compounds). He also suggested that the laws that governed how organic compounds formed, were different from those for inorganic compounds. From this, the idea developed that there was a ’vital force’ in organic compounds. In other words, scientists believed that organic compounds would not follow the normal physical and chemical laws that applied to other inorganic compounds because the very ’force of life’ made them different.

This idea of a mystical ’vital force’ in organic compounds was weakened when scientists began to manufacture organic compounds in the laboratory from non-living materials. One of the first to do this was Friedrich Wohler in 1828, who successfully prepared urea, an organic compound in the urine of animals which, until that point, had only been found in animals. A few years later a student of Wohler’s, Hermann Kolbe, made the organic compound acetic acid from inorganic compounds. By this stage it was acknowledged that organic compounds are governed by exactly the same laws that apply to inorganic compounds. The properties of organic compounds are not due to a ’vital force’ but to the unique properties of the carbon atom itself. Organic compounds are very important in daily life. They make up a big part of our own bodies, they are in the food we eat and in the clothes we wear. Organic compounds are also used to make products such as medicines, plastics, washing powders, dyes, along with a list of other items.

Density

An important property of any material is its density, defined as its mass per unit volume. A homogeneous material such as ice or iron has the same density throughout. We use (the Greek letter rho) for density. If a mass m of homogeneous material has volume V, the density is

Two objects made of the same material have the same density even though they may have different masses and different volumes. That’s because the ratio of mass to volume is the same for both objects. 

The SI unit of density is the kilogram per cubic meter . The cgs unit, the gram per cubic centimeter is also widely used:

Densities of Some Common Substances

Fluids

A fluid is any material that can flow and that takes the shape of its container. Liquids and gases are fluids.For example, you could fill a fishbowl with water or with air.Each would take the shape of the bowl. Fluids can flow because the particles in fluids move past one another easily.

Fluid statics -the study of fluids at rest in equilibrium situations. Like other equilibrium situations, it is based on Newton’s first and third laws.

Fluid dynamics - the study of fluids in motion.

Stars

Composition of Stars

To learn what stars are made of, astronomers study the light from stars. When you look at white light through

a glass prism, you see a rainbow of colors called a spectrum (plural, spectra). The spectrum consists of millions of colors, including red, orange, yellow, green, blue, and violet. Astronomers use an instrument called a spectroscope to separate a star’s light into a spectrum. The spectrum gives astronomers information about the composition and temperature of a star.

Types of Spectra

A hot, solid object, such as the glowing wire inside a light bulb, gives off a continuous spectrum. A continuous spectrum shows all of the colors. However, hot gases emit only certain wavelengths of light, or colors. When a chemical element emits light, only some colors in the spectrum show up. All of the other colors are missing. The colors that appear are called emission lines. Every element has a unique set of bright emission lines that act like a fingerprint for that element.

Types of Stars

10 Amazing Science Experiments you can do with Eggs

Watch these 10 amazing science experiments you can do with eggs. Very wow! And very simple to do. 

Michael Faraday

Michael Faraday (1791-1867). He was born on September 22, 1791 near London. He was the son of a black smith and at an early age was an apprentice to a bookbinder. He studied science in his leisure time and in 1812 he listened to the lectures of the chemist, Sir Humphrey Davy, for whom he worked as an assistant later.

Faraday discovered the principle of electromagnetic induction in 1831. His work on electrochemistry led to the discovery of the relationship between electricity and the valence of an element. This was the first clue to the electron. Faraday was the first to liquefy gases and distill benzene from fish oil. He died on August 25, 1867.

Friction

Friction is the resistance or opposition to slide one body over another. When we walk there is friction between the ground and the soles of our shoes. When a car runs, there is friction between the tires and the ground.

Uses of Friction
Friction is useful in many ways. If there is no friction we cannot attach things together. The nails and screws will not work and we cannot have houses. Dresses cannot be sewed. Even trees cannot stand and the roots cannot hold to the ground. Machines will not work without friction. The parts of machines will just slide and slip and nothing can be done.

Ways of Increasing Friction
Friction may be increased by scattering sand and pebbles on the road during rainy days when the road is slippery. This is especially true in cold countries where ice and snow cover the road. Chains are attached to the wheels of vehicles to increase friction. Shoes of runners (athletes) have spikes. Tires of automobiles and trucks have designs curved on them. The soles of rubber shoes have carved designs not just to make them look better but to increase friction.

Ways of Reducing Friction
Friction may be reduced by (1) the use of oil or grease (2) making the surface smooth by planning, filing, sandpapering or scrubbing as in floors (3) streamlining. Jet and airplanes nowadays have cambered wings and well-shaped bodies. Cards have rounded tops and nicely curved backs and fronts. Ships are elongated in shape. All these are done to reduce friction and enable the vessels to move faster in air or water. (4) Using ball or roller bearings. Roller skates make a good example. Many machines have ball bearings.

Comet on October 19

Be very excited. On October 19th something ridiculous is going to happen. A rare comet from the Oort Cloud at the edge of our solar system is going to fly past NASA’s MAVEN robot as it orbits around Mars.  It’ll be so close that they’re going to postpone work on Mars and study the comet for five days.

This will be the closest a comet’s ever gotten to Mars in human history and it’s coming from so far away that it’s likely going to have a lot of material we otherwise couldn’t find in the solar system very easily.

The chances of this happening are far less than one in a million.

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Repost from antikythera-astronomy. 

ALBERT EINSTEIN

Albert Einstein (1879–1955) was born in Germany. When he was in high school, his father’s business failed and his family moved to Milan, Italy. Einstein had to stay behind because German law required compulsory military service after finishing high school. Einstein wanted to join his family in Italy. His high school mathematics teacher wrote a letter saying that Einstein could have a nervous breakdown without his family and also that there was nothing left to teach him. Eventually, Einstein was asked to leave the school because of his disruptive behavior. Popular folklore says he left because of poor grades in Latin and Greek, but
his grades in those subjects were fine.

Einstein was visiting the United States when Hitler came to power, so he accepted a position at the Institute for Advanced Study in Princeton, becoming a U.S. citizen in 1940. Although a lifelong pacifist, he wrote a letter to President Roosevelt warning of ominous advances in German nuclear research. This led to the creation of the Manhattan Project, which developed the atomic bomb and tested it in New Mexico in 1945.

Atomic Number and Mass Number

The atomic number of an atom equals the number of protons in its nucleus. The atomic number is also the number of electrons that surround the nucleus of a neutral atom. For example, the atomic number of carbon is 6, which means that a neutral carbon atom has six protons and six electrons. Because the number of protons in an atom does not change, the atomic number of a particular element is always the same—all carbon atoms have an atomic number of 6.

The mass number of an atom is the sum of its protons and neutrons. Not all carbon atoms have the same mass number, because, even though they all have the same number of protons, they do not all have the same number of neutrons. For example, 98.89% of naturally occurring carbon atoms have six neutrons—giving them a mass number of 12—and 1.11% have seven neutrons—giving them a mass number of 13. These two different kinds of carbon atoms and are called isotopes. Isotopes have the same atomic number (i.e., the same number of protons), but different mass numbers because they have different numbers of neutrons. The chemical properties of isotopes of a given element are nearly identical

What is Calorimetry?

Calorimetry is the art of measuring energy.  For example, determining how many calories are in a cheeseburger is done with a device called a “bomb calorimeter.”  A sample of the food is burned in a closed container that is surrounded by water. The energy content of the food is determined from the temperature increase of the water jacket that surrounds the combustion chamber.

Unit Prefixes

Here are some examples of the use of prefixes:

• 70 000 m can be written as 70 km (kilometre)

• 0, 001 g is the same as 1 × 10^−3 g and can be written as 1 mg (milligram)

• 2, 6 × 10^6 N can be written as 2, 6 MN (meganewton)

Average Speed and Average Velocity

Average Speed is the ration of distance per unit time.

• Speed is always positive.
• In the SI system, the unit of speed is the meter per second (m/s)
• In practice, the speed of automobiles, aircraft, and other everyday objects is ofteneasured in kilometers per hour (km/h):

Average Velocity is the ratio of the change of position and the time interval.

is also written as:

• In the SI system, the unit of speed is the meter per second (m/s)
•  Velocity can be positive or negative. A negative velocity refers to motion in the negative direction for the coordinate axis chosen.
• We cannot tell the velocity is positive or negative until the direction at the x-axis is specified.

Newton's Law of Motion (Law of Dynamics)

• 1st Law, Law of Inertia: In the absence of a net force, a body at rest remains at rest and a body in motion will continue in motion at constant velocity 
• 2nd Law, Law  of Acceleration: When a net force acts on a body, it will be accelerated in the direction of the force with an acceleration directly proportional to the mass. (equation of motion)
• 3rd Law, Law of Interaction: When a body exerts a force on another body, the 2nd body exerts a force on the 1st body of the same magnitude but in the opposite direction.

MULTIPLES AND SUBMULTIPLES OF THE METER

kilometer (klick) - 1 km - 103 m
meter - 1 m
centimeter - 1 cm - 10 2 m
millimeter 1 mm 10 3 m
micrometer (micron) 1 m 10 6 m
nanometer 1 nm 10 9 m
angstrom 1 Å 10 10 m
picometer 1 pm 10 12 m
femtometer (fermi) 1 fm 10 15 m

Greek Alphabet

What is the importance of wiping the ice before introducing it to water in the calorimeter?

The specific heat of water is different from the specific heat of ice and also of wet ice. If the ice is not wipe before introducing into a calorimeter experiment it can increase the mass of water in the calorimeter and become source of inaccuracy.

Atoms

Atoms are the smallest particles of  matter. Atoms cannot be divided into smaller parts without changing their  properties. Atoms have a nucleus surrounded by a cloud of electrons. 

An atom consists of a tiny dense nucleus surrounded by electrons that are spread throughout a relatively large volume of space around the nucleus. The nucleus contains positively charged protons and neutral neutrons, so it is positively charged. The electrons are negatively charged. Because the amount of positive charge on a proton equals the amount of negative charge on an electron, a neutral atom has an equal number

of protons and electrons. Atoms can gain electrons and thereby become negatively

charged, or they can lose electrons and become positively charged. However, the number

of protons in an atom does not change.

Protons and neutrons have approximately the same mass and are about 1800 times

more massive than an electron. This means that most of the mass of an atom is in its

nucleus. However, most of the volume of an atom is occupied by its electrons, and that

is where our focus will be because it is the electrons that form chemical bonds.

Matter

Matter is anything that occupies space and has mass. Example, wood, plates, clothes, shoes, etc.

Classification of Matter
a. Pure Substance
     i. Element - the simplest pure substance
                     - composed of only one kind of material
                     - ex. silver, iron, aluminum
    ii. Compound - consists of two or more elements always in the same proportion
                          - can be separated into simpler substances by chemical means
                          - ex. salt, water
 b. Mixtures - two or more types of substances
                   - variable composition, can be separated by physical mean
    i. Homogeneous - the composition is uniform throughout the sample
                              - ex. air, salt water
    ii. Heterogenous - nonuniform composition
                              - ex. pizza, water and sand

States of Matter
a. Solid - has both distinct shape and definite volume
            - atoms are arranged orderly
b. Liquid - has a distinct volume but dependent of its container that is occupies
c. Gas - does not have definite shape or volume
           - particles are far apart, there's only little attraction
           - conforms to the volume and shape of it's container

Properties of Matter
a. Physical Property - a characteristic of the substance that can be observed/measured, such as color, shape, odor, luster, size, melting/boiling point and density
b. Chemical Property - a characteristic that indicates the ability of a substance to form another substance, this cannot be determined just by observing or touching the substance,
                                 - ex. Heat Combustion
c. Intensive Property - a property of matter that is dependent of the quantity of the substance but depends on the kind of matter
                                - ex. Density, boiling and melting point, specific gravity
d. Extensive Property - depends of quantity of a substance
                                 - ex. Mass, Volume

Changes of Matter
a. Physical Change - a change in physical property that retains the identity of the substance: a change in size, or a change in shape or in appearance or state
                               ex. water boiling, water freezing, sugar dissolving in water
b. Chemical Change - a change in which the original substance is converted to one or more new substances
                                - ex. paper burns, iron rusts, silver tarnishes

Elements of Scientific Method

1. Observations and measurements (quantitative data).
2. Hypothesis. A possible explanation for the observations—in other words, a tentative answer or an educated guess.
3. Experiments. The testing of a hypothesis under controlled conditions to see whether the test results confirm the hypothetical assumptions, can be duplicated, and are consistent. If not, more observations and measurements may be needed.
4. Theory. If a hypothesis passes enough experimental tests and generates new predictions that also prove correct, it takes on the status of a theory, a well-tested explanation of observed natural phenomena. (Even theories may be debated by scientists until experimental evidence decides the debate. If a theory does not withstand continued experimentation, then it must be modified, rejected, or replaced by a new theory.)
5.  Law. If a theory has withstood the test of many well-designed, valid experiments and there is great regularity in the results, that theory may be accepted by scientists as a law. This is a concise statement in words or mathematical equations that describes a fundamental relationship of nature. Scientific laws are somewhat analogous to legal laws, which may be repealed or modified if inconsistencies are later discovered. Unlike legal laws, however, scientific laws are meant not to regulate but to describe.

Science and its branches

Science (from the Latin scientia, meaning “knowledge”) - is an organized body of knowledge about the natural universe and the processes by which that knowledge is acquired and tested.

1. Social Sciences - deal with human society and individual relationships

1. Natural Sciences - investigate the natural universe.

• Biological Science (also called "Life Science") - the study of living matter
• Physical Science - the study of nonliving matter.

5 Major Divisions of Physical Science

• Physics, the most fundamental of the divisions, is concerned with the basic principles and concepts of matter and energy.
• Chemistry deals with the composition, structure, and reactions of matter.
• Astronomy is the study of the universe, which is the totality of all matter, energy, space, and time.
• Meteorology is the study of the atmosphere, from the surface of the Earth to where it
• ends in outer space.
• Geology is the science of the planet Earth—its composition, structure, processes, and history.

Happening this afternoon at Dumaguete City. Let's get involved! Lets make a difference!

I don't know what am I going to do with my life. :(
So much problems!

KABATAANG AGLIPAYANO

By Marjun Moreno

Noon at ngayon tila walang pagbabago

Dalita ay laganap pa rin sa bayan ko

Panaghoy at hibik sa guho ay namumuo

Marahas na kinitil ang liwanag ni kristo

  

Mga mangagawa samakina’y itinali

Hibla ng tubig alat sa mangingisda’y bumigti

Tipak na lupain sa magsasaka’y binawi

Kapayapaan at hustiya sa masang nasawi

Koro 1:

Tayo na kabataang aglipayano

Hawiin ang dilim at dalitang kalagayan

Lakas ay pag-isahin, ipaglas, isigaw!

Ipakita ang mukha ng maskarang kasaysayan

Koro 2:

Tayo na Kabataang Aglipayano

Suungin ang hamon,

Landasin ang kalayaan

lakas ay pag-isahin, ipiglas, isigaw!

Iguho ang moog ng maskarang kasaysayan

Darating ang liwanag sa bayan nating aba

Mapapawi ang lambong ng kahirapa’t dusa

Kasaganaan, kalayaan ang matatamasa

Kasama ang simbahan ng mga masa.

( Koro 1)

NAIS KONG AWITIN

Nais kong awitin nang aking maipagbunyi

Aking luwalhatiin ngalan mong banal.

1.    Handa nang magpuri sa iyo poong hesus, Nais kong papurihan ang ‘yong pagliligtas.

2.    Dahil sa dakila ang iyong mga gawa, 

 sa langit at sa lupa, ika’y sinasamba. 

3.    Walang hanggang pag-ibig,sa ami’y di kinait, Kagalakan sa pag giliw ang siyang inaawit.

HUWAG MANGAMBA

by Manoling Francsico

Kahit di malinaw 'yong patutunghan
Kahit di matanaw ang kinabukasan
Huwag mangamba, lagi kitang pangungunahan
Magtiwala, Ako'y sundan

Lahat ng takot mo'y aking naranasan
Lahat ng hirap mo'y aking naraanan
Kailan ako di naasahan?
Kailan kita pinabayaan?
Magtiwala, Ako'y sundan

Huwag mangamba, huwag mabalisa,
huwag mabahala
Sa ligalig, hindi kita padadakma
Manalig ka, magtiwala at mapayapa
Pag-ibig Kong kalasag mo'y sapat na

Kahit di malinaw aking kalooban
O makitid ang pinatatahak kong daan
Asahan mong kapayapaa'y matatamo sa hantungan
Magtiwala, Ako'y sundan

Huwag mangamba, huwag mabalisa,
huwag mabahala
Sa ligalig, hindi kita padadakma
Manalig ka, magtiwala at mapayapa
Pag-ibig Kong kalasag mo'y sapat na (2x)

Every girl deserves a guy that can make her heart forget that it was broken.

Your naked body should only belong to those who fall in love with your naked soul. 

Dear God, help me to understand that difficult times can make me stronger in the end, even though it may not always be easy to see.