Energy & Fuels: Energy basics

Question 1

What are the two main types of energy? what are some examples of each?

Answer 1

• Potential energy (e.g. chemical, gravitational, elastic…)
• Kinetic energy (moving water…)

Question 2

What is the SI unit of energy?

Answer 2

Joule

Question 3

What is the definition of a joule?

Answer 3

The amount of energy to heat up 0.2390g of water by 1ºC OR amount of energy transferred to an object when 1 newton is applied to an object for 1 meter

Question 4

What is the definition of energy?

Answer 4

the capacity to do work or transfer heat

Question 5

What is the formula of work?

Answer 5

W = Fd

Question 6

What do the signs of work (e.g. +W or -W ) indicate is happening to the system?

Answer 6

\+ = work done ON the system (energy going to the system)
- = work done BY the system (energy leaving the system)

Question 7

When gas is compressed or expanded, what is the work done on it?

Answer 7

compressed = +W (work done ON system)
expanded = -W (work done BY system)

Question 8

What is the ideal gas law formula? explain each component

Answer 8

PV = nRT
P = Pressure (Pa)
V = volume (M3)
n = number of mole (mol)
R = universal gas constant (8.314J mol-1 K-1)
T = temperature (kelvin)

Question 9

What is the universal gas constant? What is it calculated from?

Answer 9

• 8.314J mol-1 K-1
• Calculated as at STP (standard temperature and pressure, e.g. 273ºK [0ºC] and 1atm) for 1 mole of gas therefore occupies 22.4L of space (e.g. 2.24•10^-2m3)

Question 10

What is isothermal process?

Answer 10

When gas expansion/compression occurs and the change in temperature = 0 (however energy can flow in/out in order to maintain this)

Question 11

What is adiabatic process?

Answer 11

When gas expansion/compression occurs and the change in energy = 0 (therefore temperature and pressure will change)

Question 12

What is the first law of thermodynamics?

Answer 12

Energy can neither be created nor destroyed, the total energy of the universe is constant

Question 13

What are the two parts of the second law of thermodynamics?

Answer 13

• No actual or ideal heat engine which operates in a closed cycle can convert all the heat supplied into work
• heat of itself cannot pass from a cooler to hotter body