Element of the Day
C
Element of the Day Type: Nonmetal
Carbon /ˈkɑrbәn/ ﴾from Latin: carbo "coal"﴿ is the chemical element with symbol C and atomic number 6. It is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds. Carbon is one of the few elements known since antiquity.
There are several allotropes of carbon of which the best known are graphite, diamond, and amorphous carbon. The physical properties of carbon vary widely with the allotropic form. Diamond is among the hardest materials known, while graphite is soft enough to form a streak on paper ﴾hence its name, from the Greek word "to write"﴿. Under normal conditions, diamond has the highest thermal conductivity of all known materials.
They are chemically resistant and require high temperature to react even with oxygen. The largest sources of inorganic carbon are limestones and carbon dioxide. Carbon forms more compounds than any other element, with almost ten million pure organic compounds described to date, which in turn are a tiny fraction of such compounds that are theoretically possible under standard conditions. Carbon is the 15th most abundant element in the Earth's crust, and the fourth most abundant element in the universe by mass after hydrogen, helium, and oxygen.
Question:
A. Convert 56,000 grams to milligrams
B. Rewrite your answer in part A. in scientific notation.
1
Chemistry
1. Element of the Day ­ 5
2. Collect Unit Dimensional Analysis Activity ­5
3. Review English System vs. International System WS ­5
4. Demonstration ­ Blue Bottle ­5
5. Notes Unit Analysis/Scientific Notation­20
Assignments:
A. Due Today: Complete English System vs. International System.
B. Due Tuesday: Read pages 22 to 28 and answer questions 15, 26, 33, 34, and 36.
2
Collect Unit Dimensional Analysis Activity
Review English System vs. International System WS.
3
Question: Oxygen is corrosive, especially at high temperatures. Therefore, water that is heated in boilers must contain little oxygen gas.
How can we remove dissolved oxygen gas from water?
How can we test to determine how much is left?
4
Demonstration
0.17637 ounces of sodium hydroxide is added to beaker A
0.35274 ounces of sodium hydroxide is added to beaker B
Our scale only reads in grams, so what do we need to know to make these solutions?
1 ounce is equal to 28.3495 grams. 5
Glucose (an aldehyde) in an alkaline solution is slowly oxidised by dioxygen, forming gluconic acid:
CH2OH–CHOH–CHOH–CHOH–CHOH–CHO + 1/2 O2==>
CH2OH–CHOH–CHOH–CHOH–CHOH–COOH In the presence of sodium hydroxide gluconic acid is converted to sodium gluconate. Methylene blue speeds up the reaction, acting as an oxygen transfer agent. By oxidising glucose methylene blue itself is reduced and becomes colorless (formation of leucomethylene blue):
If there is a sufficient air in the system, leucomethylene blue is quickly re­oxidised and the blue color of solution is restored. On standing glucose reduces the dye and the color of the solution disappears. In concentrated solutions this process occurs at room temperature.
The chemistry demonstrated by this experiment is used to determine accurately dissolved dioxygen in boiler feed water. The indicator here is reduced by the glucose in the presence of base and is subsequently oxidised by the fresh dioxygen ­ a redox process.
6
Methylene blue was first synthesised by the German chemist Heinrich Caro in 1876 and since then made a medical history. The young country doctor Robert Koch discovered the tubercle bacillus with the help of methylene blue. He demonstrated that the smallest forms of life are the source of all infectious diseases. One of his pupils was Paul Ehrlich, who one day noticed that methylene blue had a surprising affinity for living cells, which it coloured an intense blue. “If only certain cells are coloured”, thought Ehrlich, “then may there not be dyestuffs which colour only the carriers of illnesses and at the same time destroy them without attacking the body’s own cells'” The revolutionary idea led to the development of chemotherapy, one of the greatest advances in medical science. Ehrlich eventually developed the famous Salvarsan==>, the most effective anti­syphilis drug. This he did in 1910, thus becoming the “father of chemotherapy”.
7
Unit Analysis Lecture
1. What is ﴾5a﴿/﴾4a﴿?
2. What is ﴾4a﴿/3?
3. What is ﴾5n2﴿/2n
In chemistry we can treat UNITS like VARIABLES!
4. What is ﴾300 meters﴿/200?
5. What is ﴾300 seconds﴿/﴾150 seconds﴿?
6. What is ﴾200 grams﴿/﴾10 degrees Celsius﴿
8
POGIL Activity
9
Lecture: Scientific Notation
Express a number as a product of a number between 1 and 10 and the
appropriate power of 10.
• Any number can be represented as the product of a number
between 1 and 10 and a power of 10 ﴾either positive or
negative﴿.
• The power of 10 depends on the number of places the decimal
point is moved and in which direction. The number of places the
decimal point is moved determines whether the power of 10 is
positive or negative. If the decimal point is moved left, then
power is positive; if the decimal point is moved right, then the
power of 10 is negative.
Examples:
1. 244,000
2. 0.0889
3. 0.10013
10
Show very large or small numbers using scientific notation!
Note: A measurement consists of a number and a unit.
7. Write 1000 as the product of a number between 1 and 10 and a power
of 10.
8. Express 92,000,000 in scientific notation.
9. Express 0.001 in scientific notation
11
Lecture: Scientific Notation
More Practice! Express the following in standard form or scientific notation.
12
Lecture: Units Indicate which scale or standard is being used to represent the results of a measurement. English system used in the United States. Metric System used everywhere else in the industrialized world. International System ﴾le Systéme Internationale﴿ also known as SI. Based on the metric system and units derived from the metric system.
Examples:
13
Note:
1 cm3 is equal to 1 mL.
1000 mL are in a 1 L.
14
15
Conversion Practice Problems
1. How many kilograms are in 5321 grams?
2. 221 microliters is how many liters?
3. How many seconds are in a day?
4. How many centimeters are in 0.219 kilometers?
16
Exit Question:
What are the two components of a measurement? Reminders:
Due Thursday: Baggy Lab and read pages 15­22 in Chemistry Textbook
Due Monday: Complete English System vs. International System.
17