Chemistry Block 2

Question 1

Chemical Reactions Example

Answer 1

●matches (phosphorus and sulfur ignite with friction)
●cooking on gas (burning chemicals to produce energy)
●engines for vehicles (burning of chemicals produce energy) like cars, buses, planes etc.
●batteries (involves chemical reactions that produce electricity)
●antacid tablets/liquids (react with HCl in stomach to reduce stomach acid)
●toothpaste (sodium fluoride in toothpaste reacts to rebuild enamel and control bacteria)
●soap and shampoo (has sodium or potassium which clean dirt and oils off body)
AND MANY MORE……………..!!!
0
4. Chemical Reactions

Question 2

The number of formula units in a mole is known as _______.

Answer 2

Avogadro’s

Question 3

What is Avogadro’s number?

Answer 3

6.02214199 x 10^23

Question 4

Atomic mass (in grams) relationship with 1 mole.

Answer 4

atomic mass (in grams) of any atom will be the mass same as the mass of 1 mole of that particular atom/element.

Question 5

A balanced chemical equation tells us about…

Answer 5

Reactants
–Products
–Their state
–Also Molar Ratios

Question 6

Stoichiometry

Answer 6

“the study of mass relationships in chemical reactions”

Question 7

Oxidation

Answer 7

the gain of oxygen and/or loss of hydrogen.

Question 8

Reduction

Answer 8

the loss of oxygen and/or gain of hydrogen

Question 9

Gas pressure

Answer 9

the force per unit area exerted against a surface.
–most commonly measured in millimeters of mercury (mm Hg), atmospheres (atm), and torr.
–SI unit is pascal

Question 10

At sea level, the average pressure of the atmosphere is _______

Answer 10

760 mm Hg, that equals to 1 atm.

Question 11

Pressure is measured using a _________

Answer 11

barometer

Question 12

Boyle’s law

Answer 12

P- V relationship

Question 13

Charles’s law:

Answer 13

T-V relationship

Question 14

Gay- Lussac’s law:

Answer 14

P-T relationship

Question 15

Combined gas law:

Answer 15

combination of these 3 gas laws

P1V1/T1=P2V2/T2

Question 16

Explains relationship between mass of gas (M) and its volume (V)

Answer 16

“Equal volumes of gases at the same temperature and pressure contain equal numbers of molecules.”

Question 17

PV = nRT

Answer 17

Where P = pressure of the gas (atm)
V = volume of the gas (L)
n = amount the gas in moles (mol)
T = temperature of the gas (K)
R = Ideal gas constant [a constant for all gases]

Question 18

three types of intermolecular forces:

Answer 18

A. London dispersion forces
B. Dipole-dipole interactions
C. Hydrogen bonding

Question 19

Although the three intermolecular forces are relatively weak compared to the strength of ionic and covalent bonds, they determine many properties of biomolecules such as_______.

Answer 19

melting point
boiling point
viscosity
3D shape

Question 20

London Dispersion Forces

Answer 20

“Extremely weak attractive forces between atoms or molecules caused by electrostatic attraction between temporary induced dipoles.”

However, at any given instant, the electron density may be shifted more towards one part of the atom than another, thus creating a temporary dipole.

0.01 to 2 kcal/mol

Question 21

Dipole-Dipole

Answer 21

“The attraction between positive end of dipole of one molecules and negative end of another dipole in the same or different molecule.”

Question 22

Hydrogen Bonds

Answer 22

“A noncovalent force of attraction between the partial positive charge on a hydrogen bonded to an atom of high electronegativity, most commonly O or N, and the partial negative charge on a nearby O or N.”

Hydrogen bonding ranges from 2 to 10 kcal/mol.

Question 23

Saturated solution:

Answer 23

that contains the maximum amount of a solute that can be dissolved at a given temperature.

Question 24

Unsaturated solution:

Answer 24

that contains less than the maximum amount of a solute that can be dissolved at a given temperature.

Question 25

Supersaturated solution:

Answer 25

that contains more than the maximum amount of a solute that can be dissolved at a given temperature under equilibrium condition.
It is not stable.
–when this solution is disturbed in any way, the excess solute precipitates- solution returns to equilibrium, and becomes merely saturated.

Question 26

Factors Affecting Solubility

Answer 26

Nature of the solvent and solute
Temperature
Pressure

Question 27

Henry’s law

Answer 27

higher the pressure, greater the solubility of a gas in a liquid.

Question 28

Concentration of solution:

Answer 28

amount of solute dissolved in a given quantity of solvent.

Question 29

When we need quantitative values, we can express the concentration of solution in 3 different ways

Answer 29

–Percent Concentration
–Molarity & Dilution
–Parts per million (ppm)

Question 30

Molarity:

Answer 30

moles of solute per liter of solution.

Question 31

Colloid:

Answer 31

a solution in which the solute particle diameter is between 1nm and 1000 nm.

Question 32

Tyndall effect:

Answer 32

a characteristic of colloids in which, light passing through the colloid, scatters.

Question 33

Brownian motion:

Answer 33

the random motion of any colloidal particle suspended in solvent.

Question 34

Add colloids chart

Answer 34

Add colloids chart

Question 35

Colligative Properties

Answer 35

“Any property of a solution that depends on the number of solute particles, and not on the nature of the particles.”

Question 36

Colligative properties are:

Answer 36

• Freezing-point depression
• Boiling-point elevation
• Osmotic pressure
• Dialysis

Question 37

Freezing-Point Depression

Answer 37

“The decrease in the freezing point of a liquid caused by adding a solute”

Question 38

Boiling point:

Answer 38

“temperature at which the vapor pressure of the substance equals atmospheric pressure.”

Question 39

Semipermeable membrane:

Answer 39

a membrane with pores that are big enough to allow solvent molecules to pass through them, but not big enough to allow the passage of larger solute molecules.

Question 40

Osmosis:

Answer 40

the movement of solvent particles through a semipermeable membrane from a region of lower solute concentration (higher solvent concentration) to a region of higher solute concentration (lower solvent concentration).

Question 41

Movement of solvent particles from higher to lower_____________ concentration.

Answer 41

Solvent

Question 42

Movement of solvent particles from lower to higher _____________ concentration.

Answer 42

solute

Question 43

Osmotic pressure:

Answer 43

the pressure necessary to prevent osmosis.

–Solution of higher concentration has a higher osmotic pressure.

Question 44

Osmolarity (osmol):

Answer 44

the molarity multiplied by the number of particles produced by each formula unit of solute.

Question 45

Isotonic solutions:

Answer 45

solutions with the same osmolarity.

Question 46

Isotonic solution:

Answer 46

a term used primarily in the health sciences to refer to a solution with the same osmolarity as blood plasma and red blood cells.
• Use of isotonic IV fluids

Question 47

Hypotonic solution:

Answer 47

a solution with lower osmolarity than blood plasma.

Question 48

Hemolysis:

Answer 48

RBC in hypotonic solution, swell and finally burst.

Question 49

Hypertonic solution:

Answer 49

a solution with higher osmolarity than blood plasma.

Question 50

Crenation:

Answer 50

RBC, in a hypertonic solution, undergo shrinkage and acquire a notched surface.

Question 51

Hemodialysis: .

Answer 51

A procedure for removing metabolic waste products or toxic substances from the bloodstream by dialysis