chem defs

Question 1

fuel

Answer 1

a substance with stored energy that can be released relatively easily for use as heat or electricity

Question 2

enthalpy

Answer 2

the chemical energy stored in a substance

Question 3

non renewable

Answer 3

rate of consumption is faster than the rate of production

Question 4

3 fossil fuels to know

Answer 4

coal, crude oil, natural gas

Question 5

fossil fuel

Answer 5

fuels found in earth’s crust and contain carbon and hydrogen, which can be burned for energy.

Question 6

coal is made from

Answer 6

wood and plant material

Question 7

crude oil is

Answer 7

(petroleum) a mixture of hydrocarbon molecules that are mostly alkanes.

Question 8

natural gas can be found

Answer 8

-in gas resorvoirs trapped between layers of rocks
-as a component of petroleum deposits
-bonded to the surface of coal deposits, known as coal seam gas (CSG)

Question 9

biofuel

Answer 9

a type of fuel derived from plant materials such as grains, sugar cane, and vegetable waste (oils)

Question 10

3 biofuels to know

Answer 10

bioethanol, biodiesel, biogas

Question 11

why do we use biofuels

Answer 11

bc they are predicted to have less impact on the environment than fossil fuels

Question 12

bioethanol

Answer 12

ethanol produced from plants such as sugar cane, used as an alternative to petrol.

Question 13

bioethanol is produced by

Answer 13

fermentation of starches and sugars. this process is accelerated using enzymes.

Question 14

biogas

Answer 14

a fuel that is produced when organic matter such as food or animal waste is broken down in the absence of oxygen.

Question 15

biodiesel

Answer 15

a renewable fuel produced in a reaction between a vegetable oil or an animal fat and a small alcohol molecule such as methanol.

Question 16

transesterification

Answer 16

the process of exchanging the organic functional group of an ester with the organic group of an alcohol.

Question 17

photosynthesis

Answer 17

the process by which green plants and other organisms use sunlight to make nutrients from carbon dioxide and water.

Question 18

activation energy

Answer 18

energy required to break the bonds of the reactants so that a reaction can proceed.

Question 19

specific heat capacity

Answer 19

the energy required to raise the temperature of 1 g of a substance by 1 degree C.

Question 20

calorimetry

Answer 20

experimental method of measuring the heat energy released or absorbed by a chemical reaction or physical process.

Question 21

calibration factor

Answer 21

amount of energy (in J or kJ) required to be released/absorbed in a given calorimeter to increase/decrease the water temp by 1 degree C.

Question 21

calibrated

Answer 21

when the instrument has been adjusted to ensure it produces accurate results

Question 22

percentage efficiency

Answer 22

percentage of energy transformed to a ‘useful’ form or transferred to a substance.

Question 23

galvanic cell

Answer 23

an electrochemical cell that converts the chemical energy of spontateneous redox reactions into electrical energy.

Question 24

what makes a collision successful

Answer 24

-reactants must collide.
-reactants must collide w/ sufficient kinetic energy to break the bonds within them (activation energy Ea).
-reactants must collide in the correct orientation.

Question 25

5 factors affecting the rate of a reaction:

Answer 25

-SA of solid reactants
-concentration of reactants in a solution
-gas pressure
-temp
-presence of a catalyst

Question 26

what does a catalyst do