a. C6(H2O)6 = six Carbon atom and six Water.

b. –

c. No. The sweetness is determined by the stereomeric structure. The ketonic functional group in fructose is sweeter than aldo functional group in glucose.

Everything is made of chemicals. It is impossible to to on chemical-free diet.

Styrofoam is a kind of polystyrene. During the production of polystyrene, foaming agent is used to form bubbles and expand the foam. When acetone dissolves the polymer, it allows the gas of the foaming agent to escape. The polymer collapses on itself and is more dense because the gas has been removed.

a. LDPE does not have the required strength as it is weak.

b. HDPE has a linear structure which is weak but extensive dispersion forces that allows molecules to slip pass one another and gives the stretch properties. In order to meet the required strength, the molecules of HDPE are arranged in the linear orientation. In order to improve the flexibility, a thin HDPE is used for surgical gloves.

When a piece of plastic is stretched, the molecules slip pass one another and the strip necks down. It arranges the molecules parallel to each other in the direction of the pull force.
The change of molecular structure is irreversible and plastic breaks when more force is applied. Paper is composed of cellulose molecules. When force is applied to paper, the paper tears. It is because the cellulose molecules in paper are more rigid and cannot be rearranged in direction of pull force.

a. non-toxic, low cost, not reactive to body fluids, not soluble in body fluids

b. PMMA is used for hard contact lenses. Desirable properties are nontoxic, permeable to oxygen, comfortable to wear, and inexpensive.

c. Hard contact lenses are typically made of PMMA which is not permeable to oxygen. Soft contact lenses are made of silicone. It allows oxygen to reach the eye. Thus, the soft lenses are more comfortable.

One carbon atom can differ from another in the number of neutrons, for example Carbon-12, carbon-13 and carbon-14.
Carbon atoms differ from all uranium atoms by its:
(a) number of protons
(b) number of neutrons
(c) number of electrons
(d) chemical properties

It shows the difference in number of neutrons, atomic mass. It also gives the information that they are isotopes.

(a) 94
(b) 93 – Neptunium
94 – plutonium
(c) 86

(a) control rods
(b) cooling water out of the core
(c) control rod assembly
(d) cooling water into the core
(e) fuel rods

– a lot of energy is required. Since it provides 1% of drinking water but takes 12500 desalination plants
– expensive
– requires more land use

Only water soluble vitamins are polar, because like dissolves like. Fat-soluble vitamins are non-polar therefore making them hydrophobic. A fat molecule has a hydrophilic head and hydrophobic tail. The fat-soluble vitamin will therefore choose the hydrophobic, non-polar tail to dissolve in.

(a) reduce use of dryer. So the electricity consumption is reduced. Thus amount of Sox produced from power plant is reduced.
(b) less Nix produced by automobiles
(c) save electricity thus less Sox produced by power plants
(d) same as (c)
(e) less shipping, so less fuel consumption, and less Nix produced

(a) coal-fired plants release SO2 -> sulphate particles that results in poor visibility. Sulphate particles reflect sunlight and results in low visibility.

(b) normal rain has a natural pH of 5-6. Thus 10 times more acidic than natural meant that pH will decrease by 1 unit. Thus resulting in an estimated pH of 4-5 at the park.

a) Exothermic. Heat released as it burns.

b) Endothermic. Water absorbs heat necessary for evaporation, skin feels cooler.

c) Endothermic. Ice absorbs heat necessary for melting.

The relative bond strength of the reactants must be stronger than that of the products.

Solid -> gas very rapidly, releasing energy quick and massive.

Heat: Energy flow from a hotter object to a colder object(motion).

Temperature: Determine the direction of heat flow, and the measure of the average speed of motion.

Example:
Heat.
1 ice on hand VS 5 ices on hand
More contact results in colder
Both case have the same temperature but more heat transferred from hand to 5 ices.

Temperature of hand is higher than ice. Therefore, heat transfers from hand to ice.

a) knocking characteristic of 98% isooctane and 2% of heptane.
– higher ability to burn smoothly without knocking
– more resistant to knocking

b) does not have enough information to know whether it contains oxygenates.