Chemistry: Energy

Question 1

Matter

Answer 1

Anything that has mass and occupies space
- weight-pull of gravity in mass
- States of Matter: Solid,Liquid, Gas

Question 2

Energy

Answer 2

• Capacity to for work or put matter into motion
• Types: Kinetic, Potential
  -Energy can be transferred

Question 3

Chemical Energy

Answer 3

Stored in bonds of chemical substances

Question 4

Electrical Energy

Answer 4

Results from movement of charged particles

Question 5

Mechanical Energy

Answer 5

Directly involved in moving matter

Question 6

Radiant or electromagnetic energy

Answer 6

Travels in waves

Question 7

Atomic structure

Answer 7

• Protons, Neutrons, Electrons
• P & N found in nucleus
• E orbit the nucleus in a cloud

Question 8

Atoms

Answer 8

• atomic # = # of protons
• Molecular weight = Protons+ Neutrons
• # of electrons = # of protons

Question 9

Isotopes

Answer 9

• Structural variation of atoms
• Differ in the number of neurons they contain
• Atomic numbers same; mass numbers different

Question 10

Atomic Weight

Answer 10

Average of mass numbers of all isotopes if an atom

Question 11

Election configurations

Answer 11

• the extent to which another atom interacts with others is deterred by the electron configuration
• Filled shell = inert
• Unfilled shell p unstable reactive

Question 12

What types of elects are found in living organisms?

Answer 12

Unstable, reactive elements

Question 13

Chemical bonds

Answer 13

• Energy relationships between electrons of reacting atoms
• electrons can occupy up to seven electron shells around the nucleus
• electrons in valance shells
  
  • have the most potential energy
  • are chemically reactive
• octet rule
  
  • except for the first shell atoms interact to have eight electrons in their valance shell

Question 14

Major elements of the human body

Answer 14

• Carbon, Hydrogen, Oxygen, Nitrogen
• makeup 96.1% of body mass

Question 15

Lesser elements of the human body

Answer 15

• 9 elements make up 3.9% of body mass
• Ca, P, K, S, Na, Cl, Mg, I, Fe

Question 16

Trace elements in the body

Answer 16

• 11 elements make up <0.01% of body mass
• Cr, Cu, F, Mn, Si, Zn

Question 17

Chemical composition of cells

Answer 17

Cells are primarily composed of macromolecules, which define the physics and chemistry of the cell

Question 18

Chemical bonds of cellular molecules

Answer 18

Water is an important chemical component of cell bonds
- polar
-water molecules form hydrogen bonds with each other
-solvent for most cellular molecules
-Reaction or product in biochemical reactions

Question 19

Mixtures

Answer 19

most matter exists as mixtures
-three types: Solution, Colloids, Suspensions

Question 20

Solutions

Answer 20

-Homogeneous mixtures
-most are true solutions in the body
- gases, liquid, solid
- Solvent: substance present in great amount
- Solute: Present in smaller amount

Question 21

Concentration of true solution

Answer 21

• % of solute in total solution
  
  • parts solute per 100 parts solvent
• milligrams per deciliter
• molarity or moles per liter (M)
  
  • 1 mole of any substance contain 6.02x10^23 molecules
  • 1 mole of any element = atomic #

Question 22

Colloids

Answer 22

• heterogeneous mixtures
• large solute particles do not settle out
• some undergo sol-gel transfer

Question 23

Suspension

Answer 23

• heterogeneous mixtures
• large, visible solutes settlers out

Question 24

Mixtures

Answer 24

-no chemical bonding between compounds
- can be separated by physical means, such as straining
- Heterogenous or homogeneous

Question 25

compounds

Answer 25

- chemical bonding between compounds - can be separated only by breaking bonds

Question 26

intramolecular interaction

Answer 26

- covalent bonds -noncovalent bonds - electrostatic attraction - hydrogen bonds - van der Waals attraction

Question 27

Intermolecular interactions

Answer 27

- electrostatic interactions - Hydrogen bonds -van der Waals attraction - Hydrophobic forces

Question 28

Covalent bonds

Answer 28

- abundant in cellular molecules - electrons shared - short length and strongest - single bonds (2E) -double bonds(4E) - nonpolar: equally shared electrons - polar: two different elements, unequal sharing

Question 29

Noncovalent bonds

Answer 29

- ionic bonds -hydrogen bonding -van der Waals attraction

Question 30

Hydrophobic forces

Answer 30

- molecules can be hydrophobic or hydrophilic hydrophilic: polar or charged that dissolve in water hydrophobic: nonpolar, insoluble in water - nonpolar surfaces tend to be pushed out of the water molecules' network - hydrophobic effects stabilize biological structures

Question 31

Chemical reactions

Answer 31

- Synthesis - Decomposition - Exchange

Question 32

Synthesis(condensation)

Answer 32

A+B -> AB Anabolic: construct molecules from smaller units

Question 33

Decomposition(Hydrolysis)

Answer 33

AB -> A+B Catabolic: molecules broken down into smaller units that are wither oxidized to realise energy, or used in another anabolic reaction

Question 34

Exchange(displacement)

Answer 34

AB+C -> AC+B bonds are both broken and made

Question 35

Redox reaction

Answer 35

- decomposition reaction - exchange reaction because electrons are exchanged between reactions

Question 36

Energy Flow

Answer 36

Exergonic: net release of energy - products have less energy than reactants - catabolic and oxidative reactions Endergonic: net absorption of reaction - products have more energy potential than reactants - anabolic reactions

Question 37

Rate of reaction

Answer 37

Affected by: - increase temperature, increase in reaction rate - increased concentration of reactants, increase in reaction rate - decrease particle size, increase in reaction rate - Catalyst: increases reaction rate

Question 38

First law

Answer 38

- there are many forms of energy: mechanical, electrical, chemical - in chemical reaction, energy is transformed from one to another: ∆U = q-w - q<0 = exothermic - q>0 = endothermic

Question 39

Free Energy

Answer 39

∆H = ∆G +T∆S ∆H: overall change in boding energy ∆G: Change in free energy ∆S: change in bond energy - when ∆G <0 :exergonic, forward reaction is spontaneous - when ∆G >0 :endergonic, reverse reaction tens to occur - when ∆G =0 : forward or reverse reaction equally probable, living things are not in equilibrium For A+B --> C+D ∆G = ∆Gº +RT ln{([C][D])/([A][B])}

Question 39

Second law

Answer 39

∆S1 + ∆S2 = ∆Su >0 S= entropy S1 = entropy of the system S2 = Entropy of surrounding Su = entropy of universe - if + then there's in increase in disorder - all spontaneous change occurs with an increase of entropy of the universe - the sum of all entropy change for the system and the surrounding must be positive for a spontaneous process

Question 40

Enzymes

Answer 40

- most chemical reactions require an energy input to start - activation energy - needed to overcome repulsive bonds between electrons of two molecules, break existing bonds - in living cells, enzymes lower the activation energy - hold substrates in a way that reduces activation energy