Q4- GEN CHEM

Question 1

A substance which speeds up a reaction but is chemically unchanged as it ends

Answer 1

Catalyst

Question 2

The process of speeding up a reaction by using a catalyst

Answer 2

Catalysis

Question 3

Types of catalyst

Answer 3

Homogeneous Catalyst, heterogeneous catalyst

Question 4

When a catalyst and the reactants are in the same physical state or phase, the reaction is considered

Answer 4

Homogenously catalyzed/ homogeneous Catalyst

Additional info: this happens mostly with gaseous catalyst-reactant pairs.

Question 5

When the catalyst and the reactant are in different phases, the reaction is said to be

Answer 5

Heterogeneously catalyzed
Additional info: common heterogeneous catalyst mostly include inorganic or a non carbon containing solid like elemental metals, sulfides and metallic salts.

Question 6

proteins that function as catalyst in all living systems. They are natural catalysts found in the body.

Answer 6

Enzymes

Question 7

They are responsible for many essential

Answer 7

Biochemical reactions

Question 8

They have components called ______ binding sites or an active site, where molecules involved in a reaction under catalysis become attached

Answer 8

substrate

Question 9

_____ ___ of Thermodynamics states that energy cannot be created or destroyed.

Answer 9

First Law

Question 10

The _______ ___ of thermodynamics states that a spontaneous process will increase the ENTROPY of the universe.

Answer 10

second law

Question 11

If the system becomes less ordered, the entropy________.

Answer 11

increases

Question 12

If the system becomes more ordered, the entropy _________

Answer 12

decreases

Question 13

Comparing entropies

The greater the number of possible microstates for a system, the higher the entropy. Microstate refers to the arrangement of the energy of each molecule in the whole system at one instant. It is directly related to the amount of the substance.

Answer 13

A. Number of Possible Microstates

Question 14

Comparing entropies

Different phases have different entropies. Gases have higher entropy than liquids and liquids have higher entropy than solids.

Answer 14

B. Phases

Question 15

the process of changing solid to liquid

Answer 15

Melting

Question 16

the process of changing liquid to gas

Answer 16

Evaporation

Question 17

the process of changing liquid to gas

Answer 17

Evaporation

Question 18

the process of changing gas to liquid

Answer 18

Condensation

Question 19

the process of changing liquid to solid

Answer 19

Freezing

Question 20

Comparing entropies

The higher the temperature, the higher the entropy

Answer 20

C. Temperature

Question 21

Comparing entropies

Compared to a pure substance, in which all particles are identical, the entropy of a mixture of two or more different particle types is greater. This is because of the additional orientations and interactions that are possible in a system comprised of nonidentical components

Answer 21

D. Mixture vs pure solvent

Question 22

Comparing entropies.

When a solid dissolve in a liquid such as sodium chloride in water, the particles of the solid experience both a greater freedom of motion and additional interactions with the solvent particles. This corresponds to a more uniform dispersal of matter and energy. The process of dissolution therefore involves an increase in entropy.

Answer 22

E. Dissolved Substances vs. Precipitate

Question 23

Comparing entropies.

The side of the equation with more moles of gas has a higher total entropy. This is because a greater number of moles indicates a greater number of gas particles and a greater number of arrangements of the gas particles.

Answer 23

F. Presence of gas

Question 24

What formula is this?
∆S reaction= ∆Sproducts - ∆Sreactant

Answer 24

Formula of entropy

Question 25

The symbol for entropy is

Answer 25

S

Question 26

standard entropy of a substance is given by the symbol

Answer 26

S°

Question 27

Standard entropy is the entropy of a substance at 25°C and 1 atm of pressure. The units for entropy are J/K mol

Answer 27

Read carefully 🐯

Question 28

Generally, a reaction is said to occur _____________ if the entropy increases. Entropy (S) is a measure of the disorder in a system.

Answer 28

spontaneously

Question 29

Are attractive forces BETWEEN molecules

Answer 29

Intermolecular forces They are important because they determine some physical properties of molecules like boiling point, melting point, and density

Question 30

Hold atoms together in a molecule

Answer 30

Intramolecular forces

Question 31

Van der waals forces Between polar molecules

Answer 31

Dipole-Dipole Interaction

Question 32

Van der waals forces Between polar and non polar molecules

Answer 32

Dipole-induced dipole interaction

Question 33

Van der waals forces Between non polar molecules

Answer 33

Dispersion forces

Question 34

the relative tendency of an atom to attract electrons to itself when chemically combined with other atoms

Answer 34

Electronegativity Values

Question 35

__________ of Molecules depends on: Electronegativity (EN) Difference Geometrical Shapes of Molecules

Answer 35

Polarity

Question 36

Electronegativity Difference (ΔΕΝ) and Type of Bonds

Answer 36

lonic Bond ≥ 1.7 Polar Covalent 0.5-1.6 Nonpolar Covalent ≤ 0.4

Question 37

formed when electrons are shared unequally by two atoms in a compound, forming an electric dipole

Answer 37

Polar Covalent Bond An atom with higher EN value becomes the partially negative pole And with lower EN value becomes partially positive

Question 38

Between ion and polar molecules

Answer 38

Ion-dipole interaction

Question 39

Between polar molecules (H must be attracted to O, N or F or another molecule)

Answer 39

Hydrogen bond

Question 40

the ability water has to flow upward against the force of gravity, due to cohesion and adhesion

Answer 40

Capillary Action

Question 41

2. Capillary Action - sticking together of two like molecules

Answer 41

• Cohesion (cohesive) -2 water molecules are cohesive due to the hydrogen bonds

Question 42

2. Capillary Action - sticking together of two unlike molecules

Answer 42

• Adhesion (adhesive) Ex: A water molecule being attracted to a sugar molecule (Like making Kool-aid) Add: 1. Polarity

Question 43

- a measure of the force necessary to stretch or break the surface of a liquid

Answer 43

Surface tension

Question 44

- amount of heat that must be absorbed or lost before it actually changes temperature

Answer 44

Specific Heat

Question 45

-The cooling of a surface occurs when the liquid evaporates

Answer 45

Heat of Vaporization

Question 46

- a measure of how compact the atoms or molecules are within a substance or how much mass there is in a given space (volume)

Answer 46

Density

Question 47

- a liquid that dissolves a particle (solute)

Answer 47

Solvent

Question 48

7. Universal Solvent - particle or liquid that gets dissolved in the solvent

Answer 48

Solute

Question 49

-A unique temperature and pressure at which three phases (usually solid, liquid, and gas) can exist together

Answer 49

Triple Point

Question 50

The temperature and pressure at which gas and liquid merge together to form a supercritical fluid. Beyond this temperature, no amount of pressure will condense the gas to a liquid

Answer 50

Critical Point

Question 51

At 1 atm pressure, the temperature at which the solid melts to liquid.

Answer 51

Normal Melting Point

Question 52

At 1 atm pressure, the temperature at which the liquid vaporizes to become a gas

Answer 52

Normal Boiling Point

Question 53

A measure of kinetic or translational energy

Answer 53

Heat

Question 54

Measure of warmth and coldness

Answer 54

Temperature

Question 55

■The _______ ______ is a graph which represents how a sample changes phases. As heat is added over time, the sample changes temperature and phase accordingly.

Answer 55

heating curve

Question 56

It is a "map" that tells us which state(s) of matter (solid, liquid, gas) exist for a given set of temperature and pressure conditions.

Answer 56

Phase diagram

Question 57

is the amount of energy needed to completely make a solid into a liquid

Answer 57

Heat fusion

Question 58

is the amount of energy needed to completely make a liquid into a gas

Answer 58

Heat vaporation

Question 59

A ratio comparing the amount of solute to the amount os solution

Answer 59

Concentration

Question 60

A homogeneous mixture of one substance(the solute) dissolved in another substance (the solvent (

Answer 60

Solution

Question 61

mass solute (g)/ mass solution (g) × 100

Answer 61

Percent mass

Question 62

volume solute (ml)/volume solution (ml) × 100

Answer 62

Percent volume

Question 63

Expresses the concentration of solution as the mass of solute in a given mass of solution

Answer 63

Ppm

Question 64

Typically used for very small Concentration

Answer 64

Ppb

Question 65

Moles • grams/1mole= grams

Answer 65

Mass to moles

Question 66

An expression of moles/Liter of the solute

Answer 66

Molarity

Question 67

Another quantitative expression of the concentration of the solution

Answer 67

Molality

Question 68

The study of quantities of materials consumed and produced in chemical reactions.

Answer 68

Stoichiometry

Question 69

The minimum energy required for a reaction to take place

Answer 69

Activation energy

Question 70

The measure of how much exposed has which is expressed in square units

Answer 70

Surface area

Question 71

Those that result in a chemical reaction and a new product is formed.

Answer 71

Effective Collisions

Question 72

A collision is considered __________ when one doesn't lead to product formation

Answer 72

Ineffective