Lab 2C was carried out and it was interesting and fun to do.
All students were asked to create flow charts of the lab beforehand to demonstrate understanding of the the procedure.
Equipment:
Safety goggles
4 Small Test Tubes
Test Tube Rack
Glass Square
2 Eye Droppers
Paper to record observations
Procedure:
Students were given four unknown substances by Mrs. Chen and were instructed to combine the different substances and record observations. Of the four substances, one was a dark greenish colour and the other three were colourless and clear.
There were a total of six possible combinations and therefore 6 observations were made. Students were directed to place one drop of the unknown solution into the given "slot" and then add a drop of another solution to see the reaction take place. This lab was focusing on studying the differences between chemical and physical changes and to see these changes occurring.
Result:
After doing the experiment, one solution remained greenish as the colourless substance did not seem to have any effect on it. Two other solutions remained clear and colourless while the other two solutions turned blue and yellow. Although a vigorous reaction did not take place, the change in colour was fascinating to see and was a good example of the purpose of the lab, which was to observe changes.
Wednesday, September 29, 2010
Tuesday, September 28, 2010
Different Properties of Matter
What is matter? You can say that matter is anything that has mass, or anything that takes up space, which is volume. Matter has many different properties; it can be broken up into two different and broad categories, pure substances, and mixtures.
Pure Substances has only one set of properties, as well as only one type of particle. Even if there are physical or chemical processes, a pure substance cannot be separated into other types of matter.
Elements cannot be decomposed because it is already in its simplest form. Although one element may have similar properties to other elements, it is still impossible for two different elements to be exactly alike. Elements are made of atoms which can be made into 3 more categories, metal, non-metal, and metalloids. Metal is a chemical element, and it conducts electricity and heat well. Metal forms cations and ionic bonds with non-metals. Non-metals do not conduct electricity or heat very well. Unlike metals, non-metals are very brittle. Metalloids have both properties similar to both metals and non-metals; some metalloids carry an electrical charge under special conditions.
Compounds are another category of pure substances. In a chemical compound, there are two or more elements that are combined chemically. In a compound, the molecule is the smallest particle; it contains multiple atoms of an element. Molecules can be split into 2 categories, ionic, and covalent. An ionic bond bonds a metal and non-metal ion together by electrostatic attraction. The ions have opposite charges, so that is what causes the attraction. A covalent bond bonds by sharing the pairs of electrons. They share the electrons between atoms and other covalent bonds. The bond is stable and balances because of the attractive and repulsive forces.
Mixtures have more than one set of properties and substances. The chemicals are not chemically united, but a mixture still is a combination of two ore more substances. Mixtures can be broken down into homogeneous and heterogeneous. The prefix “homo” means sameness, so a homogeneous mixture is uniform; it has the same appearance and composition throughout the processes. Many people call homogeneous mixtures a solution. The particles in homogeneous mixtures are too tiny to be seen. Also, in a homogeneous mixture, it seems that there is only one component. The prefix “hetero” indicates difference. A heterogeneous mixture has substances or phases that are visibly different. The particles that are in a heterogeneous mixture are larger and more visible. Also, in the heterogeneous mixture it seems to have one or more component.
In physical changes, no new substances are formed, and the chemical composition does not change. This kind of change is not reversible. Unlike physical changes, chemical changes are irreversible. New substance can be produced as a result of a chemical change
This video can help you understand the different states of matter.
http://www.youtube.com/watch?v=tBQcpF_j5Xg&feature=related
This Website can give you a general idea of what Matter really is.
http://www.chem4kids.com/files/matter_intro.html
Pure Substances has only one set of properties, as well as only one type of particle. Even if there are physical or chemical processes, a pure substance cannot be separated into other types of matter.
Elements cannot be decomposed because it is already in its simplest form. Although one element may have similar properties to other elements, it is still impossible for two different elements to be exactly alike. Elements are made of atoms which can be made into 3 more categories, metal, non-metal, and metalloids. Metal is a chemical element, and it conducts electricity and heat well. Metal forms cations and ionic bonds with non-metals. Non-metals do not conduct electricity or heat very well. Unlike metals, non-metals are very brittle. Metalloids have both properties similar to both metals and non-metals; some metalloids carry an electrical charge under special conditions.
Compounds are another category of pure substances. In a chemical compound, there are two or more elements that are combined chemically. In a compound, the molecule is the smallest particle; it contains multiple atoms of an element. Molecules can be split into 2 categories, ionic, and covalent. An ionic bond bonds a metal and non-metal ion together by electrostatic attraction. The ions have opposite charges, so that is what causes the attraction. A covalent bond bonds by sharing the pairs of electrons. They share the electrons between atoms and other covalent bonds. The bond is stable and balances because of the attractive and repulsive forces.
Mixtures have more than one set of properties and substances. The chemicals are not chemically united, but a mixture still is a combination of two ore more substances. Mixtures can be broken down into homogeneous and heterogeneous. The prefix “homo” means sameness, so a homogeneous mixture is uniform; it has the same appearance and composition throughout the processes. Many people call homogeneous mixtures a solution. The particles in homogeneous mixtures are too tiny to be seen. Also, in a homogeneous mixture, it seems that there is only one component. The prefix “hetero” indicates difference. A heterogeneous mixture has substances or phases that are visibly different. The particles that are in a heterogeneous mixture are larger and more visible. Also, in the heterogeneous mixture it seems to have one or more component.
In physical changes, no new substances are formed, and the chemical composition does not change. This kind of change is not reversible. Unlike physical changes, chemical changes are irreversible. New substance can be produced as a result of a chemical change
This video can help you understand the different states of matter.
http://www.youtube.com/watch?v=tBQcpF_j5Xg&feature=related
This Website can give you a general idea of what Matter really is.
http://www.chem4kids.com/files/matter_intro.html
Sunday, September 26, 2010
Update Sept. 26
Unit conversion and scientific notation quiz is tomorrow, Monday September 27.
Read previous post to figure out what you need to know and study your notes. Good luck to everyone...
Read previous post to figure out what you need to know and study your notes. Good luck to everyone...
Wednesday, September 22, 2010
Chemistry 11 Sept. 21, 2010 Sci Notation + Unitary Rates
Scientific Notation is a method of writing numbers that are either very large or very small. This is done using powers of 10. For example, 2.0 x 10 to the 3rd power; the 1st number must be a number between 1 and 10(not including 10)
Examples:
340000000 = 3.4 x 10 to the 8th power
7800000000 = 7.8 x 10 to the 9th power
0.00000023 = 2.3 x 10 to the -7 power.
1) Identify the number
2) Move the decimal place over as many times to make the number between one and 10 in front of the decimal. You can either move it right or move it left depending on whether the number is large or small.
3) The number of spaces that the decimal was moved is the exponent which goes in the top right corner after the 10.
http://www.youtube.com/watch?v=H578qUeoBC0
Unitary Rates:
Start with one unit and convert it by using the conversion factor.
If it requires more than one step go back to 10 to the power of 0 grams or litres.
Ex. 76.6 mL into L
= 1000 mL = 1 L
= 76.6 mL/ 1000 =(y) L
= 0.0766 L
Examples:
340000000 = 3.4 x 10 to the 8th power
7800000000 = 7.8 x 10 to the 9th power
0.00000023 = 2.3 x 10 to the -7 power.
1) Identify the number
2) Move the decimal place over as many times to make the number between one and 10 in front of the decimal. You can either move it right or move it left depending on whether the number is large or small.
3) The number of spaces that the decimal was moved is the exponent which goes in the top right corner after the 10.
http://www.youtube.com/watch?v=H578qUeoBC0
Unitary Rates:
Start with one unit and convert it by using the conversion factor.
If it requires more than one step go back to 10 to the power of 0 grams or litres.
Ex. 76.6 mL into L
= 1000 mL = 1 L
= 76.6 mL/ 1000 =(y) L
= 0.0766 L
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