chemistry

Question 1

accuracy

Answer 1

refers to a measurement giving the actual value for the sample w/ a limited deviation

Question 2

precision

Answer 2

the repeatability of a set of measurements on the same sample

Question 3

test tubes

Answer 3

relatively small & allow a large # of samples to be arrayed in a rack for easy processing

Question 4

beakers

Answer 4

wide mouth cylinders w/ a lip to allow pouring

Question 5

erlenmeyer flasks

Answer 5

tapered & therefore minimize accidental spills

neck is able to be clamped in place

Question 6

round bottom flasks

Answer 6

used for reaction, heating, or vacuum applications

can fit into heating mantle

neck is able to be clamped in place

Question 7

retort

Answer 7

round vacuum flask w/ a long neck that extends to the side

used for distillation & must be placed in a ring stand

Question 8

extraction flask

Answer 8

aka separatory funnel

teardrop shaped flask w/ ground glass stopper at the top and the stopcock at the bottom

Question 9

transfer pipets

Answer 9

made of plastic

have an integral bulb at the top

Question 10

pasteur pipets

Answer 10

made of glass w/ a long tapered tip & require a separate rubber pipet bulb

Question 11

bell jars

Answer 11

used to contain vacuums

Question 12

watch glasses

Answer 12

aka evaporating dishes

shallow glass plates used as evaporating surfaces or to cover beakers

Question 13

calibrated glassware

Answer 13

should be used for any lab experiment that requires accuracy & precision

Question 14

graduated cylinder

Answer 14

a tall, narrow tube w/ volume markings increasing from bottom to top and a lip at the top for pouring

Question 15

meniscus

Answer 15

concave or convex depending on liquid

Question 16

buret

Answer 16

long tube that is clamped in place vertically w/ a stopcock at the bottom

useful with liquids are to be dispensed slowly or dropwise

used to make solutions and perform titration

Question 17

graduated pipet

Answer 17

handheld and controlled by a pipet bulb that maintains a slight vacuum at the top of the pipet

Question 18

volumetric pipets

Answer 18

have a large bulge in the middle of the tube & deliver a single established volume of liquid w/ accuracy and precision

Question 19

volumetric flask

Answer 19

used to make solutions that require a specific volume of liquid, such as molar solutions

Question 20

pH meter

Answer 20

an important piece of measurement equipment consisting of a glass probe and an electronic meter

Question 21

litmus paper

Answer 21

can be used to quickly determine pH

less accurate than pH meter`

Question 22

standard lab balances

Answer 22

used when weights are in the milligram range & require accuracy to w/in +/- 0.5 mg

Question 23

analytical balances

Answer 23

used for much more sensitive weighing applications, w/ accuracy to +/- 0.01 mg

Question 24

calorimetry

Answer 24

a way to measure the energy content of a substance

Question 25

bomb calorimetry

Answer 25

one of the most common versions of calorimetry

Question 26

atom

Answer 26

basic building block of matter representing the smallest unit of a chemical element

Question 27

subatomic particles

Answer 27

protons, neutrons, and electrons

Question 28

nucleus

Answer 28

central core of the atom protons and neutrons

Question 29

orbitals

Answer 29

outside of the nucleus where electrons are

Question 30

elements

Answer 30

composed of very small particles called atoms atoms from one element are different from atoms of all other elements

Question 31

isotopes

Answer 31

atoms of the same element w/ different masses due to different # of neutrons

Question 32

compounds

Answer 32

composed of atoms of more than one element

Question 33

chemical reaction

Answer 33

involves separation, combination, or rearrangement of atoms does not result in creation or destruction of atoms

Question 34

atomic number

Answer 34

equal to the # of protons found in an atom of that element

Question 35

valence electrons

Answer 35

electrons in the electron shell farthest from the nucleus

Question 36

ion

Answer 36

+ or - charge on an atom due to loss or gain of electrons

Question 37

mass number (A)

Answer 37

equal to the total number of nucleons (protons & neutrons) mass # (A) = # of protons + number of neutrons

Question 38

molecular weight

Answer 38

the weight in grams per one mole of a given element

Question 39

mole

Answer 39

unit to count particles and is represented by avagadro's # (6.02x10^23)

Question 40

quantum theory

Answer 40

proposed by max planck in 1900 energy emitted as electromagnetic radiation from matter comes in discrete bundles called quanta

Question 41

energy value of quantum

Answer 41

E = hf h is planck's constant (6.626x10^-34 J*s f is the frequency of radiation

Question 42

angular momentum

Answer 42

L = mvr

Question 43

kinetic energy

Answer 43

(KE = (mv^2)/2)