A)C6(H2O)6

B) Refer to hardcopy 🙂

C) Yes, their sweetness is different from each other. This is because of the different way they interact with our sweet receptors.

Organic foods are produced by methods that comply with a variety of standards of organic farming. It does not mean that organic food are chemical free. It just means that they are not farmed with “harmful” pesticides and fertilizers and are not processed. Generally, it should be called “harmful – chemical free”.

The acetone dissolves the styrofoam. the gas that was initially trapped in the polymer chain escaped. Hence, a denser polymer is formed.

a. LDPE is not strong enough to resist being cut.
b. Linear HDPE offers the required flexibility while maintaining its strength compared to the normal HDPE.

The same thing will not happen when you pull a piece of paper. Paper is made from cellulose which has more crystalline-like properties compared to plastic which is amorphous. When plastic is stretched, the polymer chain aligns with each other in the direction of the force. Crystalline structure would break due to its rigid structure more easily.

The benefits for polymers intended for use in the body should far outweigh any risks. The two main properties are
(1) stable over time of intended use
(2) non-toxic
(3) inert (not reactive, not soluble)
(4) does not cause allergy to human body

b. Several different types of contact lenses are on the market and each uses a different type of polymer. Polymethyl methacrylate (PMMA), one of the earliest polymers used for rigid gas permeable lenses, is structurally similar to Lucite and plexiglas. Silicone-acrylate materials now are more commonly used under trade names such as Kolfocon. Newer rigid gas permeable (RGP) polymers contain fluorine: fluoro-silicone-acrylate polymers and fluoro-silicones. Polymacon (38% water) is typical of the polymers used for soft lenses and is a polymer of 2-hydroxyethyl methacrylate (HEMA). Other methacrylates include hioxifilcon (48% water) and methafilcon (55% water) or even lidofilcon (70% water). Manufacturers’ websites are good sources of information. Desirable properties include being nontoxic, permeable to oxygen, comfortable to wear, and inexpensive. Also desirable is the ability to conform to the shape of the eye and to be easily cleaned (if not disposable).

c. As mentioned in the previous part, hard contact lenses are typically made of PMMA, a rigid non-gas permeable plastic. The soft contact lenses that replaced them are made of silicone, which is flexible and allows oxygen to reach the eye. Because of these properties, the soft lenses tend to be more comfortable.

Two ways in which one carbon atom can differ from another.
1)Different neutron number in nucleus
2) Different electron number ( ions of carbon )

Three ways in which all carbon atoms differ from all uranium atoms
1)Different neutron number
2) Different proton number
3) Different electron number

14N : mass of this atom is 14u
– 7 neutrons
– 8 protons

15N : mass of this atom is 15u
– 8 neutrons
– 7 protons

3a) 94 protons

3b) 93 Protons : Neptunium
94 Protons : Plutonium

3c) 86 protons

A – Control Rod assembly
B – Cooling water out of the core
C – Control rods
D – Cooling water into the core
E – Fuel rods

The most common desalination techniques are reverse osmosis and distillation. These methods are considered highly expensive in order to acquire portable water. A large amount of energy is required to perform desalination techniques thus making the process costly. Since there may be less expensive options available to acquire portable water, these options take precedence over desalination techniques.

Vitamins that are water soluble are polar because being soluble in water requires the formation of hydrogen bonds with water molecules.

Whereas fat soluble vitamins have to be non polar. This is because fat is a triglyceride, and contains a long hydrocarbon chain, making fat non polar.

a. Hanging of laundry is more environmentally friendly than through the use of electric means such as a clothes dryer or tumbler. For an electric dryer, cutting down on energy use cuts down on the need for power companies to produce electricity by burning coal.

alt answer:

The residual chemicals from the washing agent which is basic is evaporated into the atmosphere.

b. These options reduce the amount of gasoline used by cutting down on the harmful emissions when gasoline is burnt to produce energy to power these equipments.

c. same answer as A

d. Additional insulation on hot water heaters and pipes prevent heat loss to the surroundings, saving on the energy used by the heater.

e. Buying locally grown produce promotes shorter transportation routes which will reduce the amount of gasoline used.

a. The coal fired plants releases carbon dioxide, sulphur dioxide, nitrogen oxides and mercury compounds when burning coal. The released sulphur dioxide creates sulfate particles that hinders visibility.

b. pH of normal rain ranges from 5 to 6. Thus, if the park is 10 times more acidic, the pH range must be from 4 to 5.

A) Exothermic – Because heat energy is released during the process.
B)Endothermic – Water molecules absorb energy in order to change its state from liquid to gas.
C)Endothermic – Water molecules absorb energy in order to change its state from solid to liquid.

Energy is taken in to break the bond for the reactant. Energy is released when the bond is formed in the product. An explosion requires large amounts of energy to be released. In order to produce a very exothermic reaction, the net energy is produced must be very high. Hence, the bond strength of the product must be a lot higher than that of the reactant.

Temperature is the measurement of heat. Heat is the amount of energy. Higher temperature object will transfer energy to lower temperature object until both has the same amount of energy. Example, temperature of a cup of water and a pail of water could be both 25 degree. but obviously the pail of water has more heat because of its larger mass.

Another difference to note is that temperature has unit of Kelvin(K) while heat has a unit of joules(J).

A) It has a knocking characteristics of 98% octane and 2% ethane.
B) No it does not