EXAM III

Question 1

five visual evidences of a chemical reaction

Answer 1

1. color change
2. formation of a solid
3. formation of a gas
4. emission of a light
5. emission or absorption of heat

Question 2

limiting reactant

Answer 2

the reactant which gets used up first, completely in a chemical reaction

Question 3

theoretical yield

Answer 3

amount of product which can be produced based on the amount of limiting reactant

Question 4

actual yield

Answer 4

amount of product that is actually isolated in reactipon

Question 5

percent yield

Answer 5

actual/theoretical x 100

Question 6

negative ΔH rxn

Answer 6

exothermic

Question 7

positive ΔH rxn

Answer 7

endothermic

Question 8

solvent

Answer 8

majority component

Question 9

solute

Answer 9

minority component

Question 10

electrolyte solution

Answer 10

ionic compound dissolved in water; dissolved salt ions; conducts electricity well

Question 11

non-electrolyte solution

Answer 11

dissolved sugar molecules; does not conduct electricity well

Question 12

solubility

Answer 12

amount of solute which can dissolve in a fixed amount of solvent

Question 13

saturated solution

Answer 13

holds dissolved the maximum amount of solute

Question 14

concentration

Answer 14

quantity of a solute dissolved in a fixed amount of solvent

Question 15

mass percent of solution

Answer 15

mass solute/mass solution x 100

Question 16

molarity of solution

Answer 16

most common way to measure solution concentration; moles per 1L or M solution

Question 17

solution dilution

Answer 17

diluting stock solutions to decrease the concentration (molarity)

Question 18

molarity (M)

Answer 18

mol solute/1L solution

Question 19

molarity (m)

Answer 19

mols solute/1kg solvent

Question 20

colligative properties

Answer 20

solution properties which are determined only by the concentration of a particular solute in it

Question 21

freezing point depression

Answer 21

lower than that of the pure solvent; directly proportional to molality of solute

Question 22

kinetic molecular theory

Answer 22

collection of particles in constant motion; no attraction/repulsion between particles; a lot of space between particles compared to size of particles; speed of particles increases with temp.

Question 23

measureables of a gas

Answer 23

volume, temperature, pressure

Question 24

boyle’s law

Answer 24

P(1)V(1)=P(2)V(2)
inverse relationship between p and v

Question 25

charles’ law

Answer 25

V(1)/T(1)=V(2)/T(2)
direct relationship between V and T

Question 26

The combined gas law

Answer 26

P(1)V(1)/T(1)= P(2)V(2)/T(2)
inverse relationship between P and V
direct relationship between V and T

Question 27

Avogadro’s Law

Answer 27

V(1)/n(1)=V(2)/n(2)
direct relationship between V and # of moles (n)

Question 28

ideal gas law

Answer 28

PV=nRT

Question 29

gas constant

Answer 29

R= 0.082 L x atm/mol x K

Question 30

Dalton’s law of partial pressures

Answer 30

each of the components of a gaseous mixture exert a partial pressure independent of those of the other gases in the mixture
P (total)= P(1)+P(2)

Question 31

Viscosity

Answer 31

resistance of a liquid to flow
greater in substances w/ stronger intermolecular forces
long molecules

Question 32

Surface Tension

Answer 32

tendency of liquids to minimize surface area
unequal intermolecular forces on surface particles creates a “skin”
generally increase w/ increasing intermolecular forces

Question 33

dispersion forces

Answer 33

weakest intermolecular forces
exhibited by all particles

Question 34

dipole-dipole forces

Answer 34

intermediate strength intermolecular force
exhibited only by certain particles

Question 35

hydrogen bonding

Answer 35

strongest intermolecular forces

Question 36

Particles which bear only dispersion forces

Answer 36

nobles gasses
hydrocarbons