MYP/DP 10 Chem 2013-14 Phenomenon Study

Topic / Big Ideas / Phenomenon
(1)
Acids & Bases / Chemical reactions are the driving force of life.
Acid and Base reactions occur in everyday life and are essential for understanding our world. / (a) Why does disappearing ink disappear?
(b) Why is milk of magnesia an Antacid?

(c) Books that have been published since the mid-nineteenth century suffer from yellowing, brittle pages as they age.
How might acids cause this problem?
Can you think of any solutions to this problem?

(d) Why do people who own aquariums and swimming pools need to monitor the pH of the water.

(e) Why do gardeners and farmers need to determine the pH of the soil?
(f) Why is it important that the pH of your blood must remain within narrow limits?
(2)
Quantitative Chemistry / Chemistry has accepted methods of communicating chemical information that ensures the uniform study and understanding of matter.
Chemistry uses mathematics to express relationships efficiently and accurately.
The inter-relationships of measured quantities of matter within a chemical change can be expressed, monitored, and predicted through mathematics.
The number of atoms that begin a reaction must equal the number of atoms at the end of a reaction.
Scientists construct and use models to predict changes, generate knowledge, develop theories and laws and apply mathematics to quantify these relationships efficiently and accurately. / (a) How do recipe writers know that they have the right number of molecules of each ingredient to ensure tasty muffins?
(b) Phenol is a hazardous liquid, especially when it is at room temperature. It is a volatile chemical. Inhaling phenol adversely affects the central nervous system, and can lead to a coma. Inhalation is not the only danger.
Coma and death have been known to occur within 10 min after phenol has contacted the skin. Also, as little as 1 g of phenol can be fatal if swallowed.

Would you expect to find such a hazardous chemical in over-the counter medications? You may find phenol listed as an ingredient in throat sprays and in lotions to relieve itching. You may also find it used as an antiseptic or disinfectant.
Is phenol a hazard or a beneficial ingredient in many medicines?
(c) Boyle’s law: Weather balloons are partially inflated with helium. They carry specialised instruments to measure varying atmospheric conditions such as pressure, temperature, and humidity.

(d ) Gay-Lussac’s law
Aside from balloons and syringes, most containers that are used to store gases have a fixed volume. You know that temperature is a measure of the average kinetic energy of the molecules making up a substance. If the temperature of a gas increases, but the volume of its container cannot increase, what happens to the pressure of the gas inside?
Most cylinders used to store gases have safety devices regulating the internal gas pressure. The most common of these is a pressure relief valve.

(4)
Atomic structure / Scientists construct and use models based upon observations and experimental data to generate knowledge and advance understanding.
Matter is made from discrete fundamental units called atoms. / (a) Why does a kitchen gas burner glow yellow when liquid comes into contact with it?

(5) Periodic Table / Constancy, patterns and change are found in all systems. / (a) Analyzing the Ice Man’s Axe
In September 1991, hikers in the Alps Mountains near the Austrian-Italian border discovered the body of a man who had been trapped in a glacier. He was almost perfectly preserved. With him was an assortment of tools, including an axe with a metal blade. How would you determine the identity of the metal?

(b) Gas-filled airships and balloons now use helium gas instead of hydrogen. Why?
(6) Bonding / Chemical and physical properties of materials can be explained by the structure and arrangement of atoms, ions, and molecules and the forces between them. / (a) Fullerenes found its many application in the semi-conductors industry.
What is/are the properties of fullerene that makes it a good semi-conductor?

(b) Water may be liquid, solid, or gas in nature. Why does the water that is sprayed up by this skier form a sheet?

(c) Dinitrogen monoxide, also known as laughing gas, boils at about −89°C. Laughing gas is used as an anaesthetic for dental work.

(7)
Energetics / Heat transformations are involved in all chemical reactions.
Any bond or intermolecular attraction that can be formed, can be broken. / (a) What causes an instant ice-pack to cool?

(b) Why do cosmetic cold creams feel cool when applied to the skin?
(c) Why is oxyacetylene torch used by metal workers to cut through most metal alloys?

(d) The Hindenburg was an airship that was held aloft by massive quantities of hydrogen. Something aboard the airship triggered an explosion which ignited the hydrogen, causing the massive airship to explode violently, killing 35 people. Many different theories have been put forward to explain the sudden explosion, but the true cause was never conclusively determined.
(8) Kinetics / The rate at which one atom/molecule reacts with another atom/molecule is influenced greatly by the concentrations of the individual species undergoing the reaction, the rate of collisions between molecules, and by the energy needed for atoms/molecules to react individually or with one another. / (a) Why do people put batteries in the refrigerator?
(b) What causes the book to turn brown, black and fragile?
Can we do something to slow down the rate of the papers of old books becoming fragile?
ie, can we slow down the rate of reaction.

(9)
Equilibrium / Chemical systems are dynamic and respond to changing conditions in predictable ways.
Applications of chemical systems at equilibrium have significant implications for nature and industry. / (a) Many mountain climbers use pressured oxygen at very high altitude to maintain proper haemoglobin – oxygen equilibrium.

(10) Redox / Chemical processes can cause a change in the chemical, and therefore physical, properties of substances.
Oxidation and reduction are paired chemical reactions in which electrons are transferred from one substance to another in a predictable way.
Electricity can be generated through chemical reactions.
The control and applications of oxidation and reduction reactions have significant implications for industry, health and safety, and the environment / (a) What happens if an unwanted old car is left in the open air?

(b) Thermit Process to weld steel railway lines together

(c) This car wheel is made from aluminium metal plated with nickel in a more environmentally friendly process developed by Metal Arts Company, Inc. The process uses about 30 percent less electricity, nearly 60 percent less natural gas, and half the water that conventional plating processes need.

(11)
Organic Chem / Humans have used unique bonding of carbon atoms to make a variety of molecules.
Structure controls functions.
Each functional group has predictable reactivity. / (a) How can just two elements, carbon and hydrogen, account for 90% of all the biological matter on Earth?

(b) Halong Bay – an UNESCO World Heritage Site. Villagers are seen selling home-made Corn Wine along the streets! This corn wine has 50% v/v alcohol (ethanol) content!

(c) The candle produces a yellow flame. Propane burning in a propane torch produces a blue flame.

(d) What do tires and chewing gum have in common?

(e) Steroids are organic compounds. Our bodies make steroids naturally.
Steroids may also be synthesized in chemical laboratories. What do the structures of these steroids have in common?