Chapter 2

Question 1

Potential energy/Chemical energy –

Answer 1

Definition: Energy stored within the structural units of chemical substances.

Comes from bond formation between particles of matter

Question 2

Functions of PE

Answer 2

Energy that holds atoms together, such as when the nucleus of one atom
attracts an electron of another atom (e.g., the C-C bond in ethane) (intramolecular bond).

Energy from two molecules (e.g., methanol and methanol, or methanol and acetone) forming an intermolecular bond.

Question 3

Kinetic energy

Answer 3

Definition: Energy that results from motion

E = 1⁄2mv^2

Kinetic energy consists of translational, rotational and vibrational motion.

Question 4

Relationship of KE and PE

Answer 4

At height, the book has high PE and no KE. As the book drops the potential energy decreases, and the kinetic energy increases. When the book hits the
ground it converts its kinetic energy into thermal energy.

Question 5

Laws of Conservation of Energy

Answer 5

1. The energy of the universe is constant.
2. Energy cannot be created or destroyed.
3. When energy of one form disappears, the same amount of energy must appear in another form(s)

Question 6

Precision

Answer 6

Reproducibility. Closeness of the individual values to the average value.

Question 7

Systematic error

Answer 7

error that tends to be either too high or too low.

Does not tend to average itself out

Question 7

Accuracy

Answer 7

Correctness. Closeness of the average value to the correct value.

Question 8

Random error

Answer 8

Error that has equal probability of being too high or too low.

Tends to average itself out

Question 9

System

Answer 9

That part of the universe we are studying (e.g., methane reacting with oxygen in a
cylinder)

Question 10

Unit of energy

Answer 10

Joule

Named after the English physicist James
Joule. It is the amount of kinetic energy possessed by a 2-kg mass moving at a
speed of 1m/s.

Ek = 1/2mv^2

1 cal = 4.184

Question 11

Surroundings

Answer 11

The rest of the universe

Question 12

∆U = q + w

Answer 12

change of internal energy of the system = heat absorbed by the system plus work done on the system.

Question 12

Heat “q”

Answer 12

• quantity of energy transferred between a system and its surroundings
• It is positive if the system absorbs heat from the surroundings;
• it is negative if the system releases heat to the surroundings (i.e., if the surroundings
  absorbs heat from the system)

Question 13

Work

Answer 13

• Done when a force moves through a distance
• is positive if the system is compressed by the surroundings;
• is negative if the system is expanded by the surroundings (i.e., if the surroundings
  is compressed by the system)

Question 14

Exothermic reaction

Answer 14

Heat is given off by the system to its environment due to stronger bonds being form

Question 15

Metric system prefixes

Answer 15

Multiple Prefix
10^9 giga (G)
10^6 mega (M)
10^3 kilo (k)
10^-1 deci (d)
10^-2 centi (c)
10^-3 milli (m)
10^-6 micro (μ)
10^-9 nano (n)
10^-12 pico (p)

Question 16

Grams to lb

Answer 16

454 g to 1 lb

Question 17

Cm to inches

Answer 17

2.53 cm = 1 in

Question 18

Millimeter to meter

Answer 18

1 mm = 0.001 m
1000 mm = 1 meter

Question 19

Kilometer to meters

Answer 19

1 km = 1000 m

Question 20

Centimeters to mL

Answer 20

1 cm^3 = 1 mL

Question 21

centimeters to meters

Answer 21

1 cm = 0.01 m

Question 22

Mole

Answer 22

defined as number of atoms in 12 g of 12^C