Chemistry
Which of the following correctly expresses 52,030.2 m in scientific notation? a) 5.20302 x 10 4 m b) 5.20 x 10 4 m c) 5.20302 x 10 5 m d) 5.2 x 10 4 m e) 5.203 x 10 4 m
5.20302 x 10 4 m
Avoadro's number (N) or 1 mol
6.022x 10 *23rd*
Max Planck
German physicist whose explanation of blackbody radiation in the context of quantized energy emissions initiated quantum theory (1858-1947)
Law of Conservation of Matter
Matter is not created nor destroyed in any chemical or physical change
Systematic Error
Values that are either all higher or all lower than the actual value
mass percent formula
% = part/whole x 100 %
Wavelength
(A, Greek "lambda") the distance between any point on a wave to the corresponding point on the next wave expressed in units of meters.
Celsius to Fahrenheit
(C x 1.8) + 32
Fahrenheit to Celsius
(F-32)/1.8
The S.I. unit of speed (velocity) is Question options: a) km/h b) km/s c) m/h d) m/s e) none of these choices is correct
m/s
Which of the following is an extensive property of oxygen? a) boiling point b) density c) temperature d) mass e) average kinetic energy of molecules
mass
Density Formula
mass/volume
Neutrons
uncharged particles in the nucleus with mass approximately equal to a proton
JJ Thomson
used the cathode ray tube to discover electrons, plum pudding model
Which one of the following is a "substance" in the sense of the word as used in your textbook? a) air b) tap water c) sea water d) water e) toothpaste
water
Frequency
(v, Greek "nu") - the number of cycles the wave undergoes per second expressed as 1/second or s-1.
Celsius absolute zero
-273
Fahrenheit absolute zero
-460 degrees
The area of a 15-inch pizza is 176.7 in2. Express this area in square centimeters. a) 1140. cm2 b) 448.8 cm2 c) 96.8 cm2 d) 69.57 cm2 e) 27.39 cm2
1140. cm2
Acetone, which is used as a solvent and as a reactant in the manufacture of Plexiglas®, boils at 56.1°C. What is the boiling point in degrees Fahrenheit? a) 159°F b) 133°F c) 101°F d) 69.0°F e) 43.4°F
133°F
Robert Millikan
1909 oil drop experiment, calculated the charge of the electron, calculate the mass of electrons
How fast does electromagnetic radiation travel?
2.99792458 x 108 m/s or 3.00 x 108 m/s
Select the answer with the correct number of decimal places for the following sum: a) 269.01860 cm b) 269.02 cm c) 269.0186 cm d) 269.0 cm e) 269.019 cm
269.0 cm
Freezing point in kelvin
273
What is the energy of one photon with a wavelength of 590 nm?
3.37×10-19 J
Freezing point in Fahrenheit
32
Accuracy
Refers to how close a measurement is to the actual value
speed (c)
The product of a wave's frequency and its wavelength
Temperature
a measure of how hot or cold an object is
Which of the following correctly expresses 0.000007913 g in scientific notation? a) 7.913 x 10 6 g b) 7.913 x 10-6 g c) 7.913 x 10 5 g d) 7.913 x 10-9 g e) 7.913 x 10-5 g
7.913 x 10-6 g
Express 96,342 m using 2 significant figures. a) 9.60 x 10 4 m b) 9.6 x 10-4 m c) 9.6 x 10 4 m d) 96,000. m e) 9.60 ´ 10-4 m
9.6 x 10 4 m
average mass
= ∑(𝑓𝑟𝑎𝑡𝑖𝑜𝑛𝑎𝑙 𝑎𝑏𝑢𝑛𝑑𝑎𝑛𝑐𝑒)(𝑖𝑠𝑜𝑡𝑜𝑝𝑒 𝑚𝑎𝑠𝑠)
Absolute zero definition
The lowest temperature that ceases all movement of matter
You prepare 1000. mL of tea and transfer it to a 1.00 quart pitcher for storage. Which of the following statements is true? a) The pitcher will be filled to 100% of its capacity with no tea spilled. b) The pitcher will be filled to about 95% of its capacity. c) The pitcher will be filled to about 50% of its capacity. d) The pitcher will be completely filled and a small amount of tea will overflow. e) The pitcher will be completely filled and most of the tea will overflow.
The pitcher will be completely filled and a small amount of tea will overflow.
fundamental unit of charge
The smallest measured electric charge, which belongs to a single proton or electron, and is equal to 1.6x10^-19 C.
What is the frequency (in s-1) of the electromagnetic radiation from blue sky ( = 473 nm)?
6.34 x 1014 s-1
Which measurement is expressed to 4 significant figures? a) 0.00423 kg b) 24.049 cm c) 1300 K d) 82,306 m e) 62.40 g
62.40 g
A dose of medication was prescribed to be 35 microliters. Which of the following expresses that volume in centiliters? a) 3.5 ´ 105 cL b) 3.5 ´ 10-4 cL c) 3.5 ´ 104 cL d) 3.5 ´ 10-3 cL e) 3.5 cL
d) 3.5 ´ 10-3 cL
A cook uses a microwave oven to heat a meal. The wavelength of the radiation is 1.20 cm. What is the energy of one photon of this microwave radiation?
1.66 x 10 (-23) J
A flask has a mass of 78.23 g when empty and 593.63 g when filled with water. When the same flask is filled with concentrated sulfuric acid, H2SO4, its mass is 1026.57 g. What is the density of concentrated sulfuric acid? (Assume water has a density of 1.00 g/cm3 at the temperature of the measurement.) a) 1.992 g/cm3 b) 1.598 g/cm3 c) 1.840 g/cm3 d) 0.543 g/cm3 e) 1.729 g/cm3
1.840 g/cm3
Boiling point in Celsius
100
Which of the following represents the largest volume? a) 10,000 µL b) 1000 pL c) 100 mL d) 10 nL e) 10 cm3
100 mL
The S.I. prefix mega- (M) means a) 10x-6 b) 10x-3 c) 10x3 d) 10x6 e) 10x9
10x6
Boiling point in Fahrenheit
212 degrees
Ion
charged atom due to unequal numbers of protons and electrons
Electron
negatively charged particles, surround nucleus
electromagnetic radiation
energy propagated through space by means of alternating electric and magnetic fields.
Albert Einstein
explained the photoelectric effect in terms of the absorption of small bundles of electromagnetic energy. He termed these 'particles' of electromagnetic energy as light quanta.
empirical formula
indicates atoms present in compound in the simplest whole-number ratio of atoms
Atoms
indivisible particle that is the smallest unit of an element
atomic number (z)
number of protons in nucleus
The density of mercury, the only metal to exist as a liquid at room temperature, is 13.6 g/cm3. What is that density in pounds per cubic inch? a) 849 lb/in3 b) 0.491 lb/in3 c) 491 lb/in3 d) 1.83 x 10-3 lb/in3 e) 376 lb/in3
0.491 lb/in3
Iron (Fe) is the main component of steel and is therefore the most important metal in society; it is also essential in the body. How many Fe atoms are in 95.8 g of Fe?
1.04 x 1024 atoms Fe
The average distance between the Earth and the Moon is 240,000 miles. Express this distance in kilometers. a) 6.1 ´ 105 km b) 1.5 ´ 105 km c) 5.3 ´ 105 km d) 9.4 ´ 104 km e) 3.9 ´ l05 km
3.9 ´ l05 km
Boiling point of Kelvin
373
molecular formula
A chemical formula that shows the number and kinds of atoms in a molecule, but not the arrangement of the atoms.
Scientific Notation
A method of writing or displaying numbers in terms of a decimal number between 1 and 10 multiplied by a power of 10.
Density
A physical property that relates the mass of a substance to its volume.
Ammonium carbonate, (NH4)2CO3, a white solid that decomposes on warming, is an component of baking powder. a)How many molecules are in 41.6 g of ammonium carbonate? b) How many O atoms are in this sample?
A. = 2.61x10(23) molecules (NH4)2 CO(3) B.= 7.83 x 10(23) O atoms
Ernest Rutherford is credited with...
All positive charge in an atom is concentrated in a tiny, heavy nucleus located at the atom's center (Gold Foil Experiment). Also discovered the Atomic Nucleus.
Law of Definite Proportions
All samples of a pure compound contain the same elements in the same proportion by mass
Anion
An atom that gains one or more electrons will exhibit a negative charge
Cation
An atom that loses one or more electrons will exhibit a positive charge
Isotopes
Atoms of the same element that have different numbers of neutrons / have the same atomic number (# protons)
absence of a time lag
Current flows the moment light of the minimum frequency shines on the metal, regardless of the light's intensity
At the turn of the 20th century, three phenomena involving matter and light confounded physicists
Blackbody radiation, The Photoelectric Effect, Atomic Spectra
Bud N. Chemist must determine the density of a mineral sample. His four trials yield densities of 4.77 g/cm3, 4.67 g/cm3, 4.69 g/cm3, and 4.81 g/cm3. Independent studies found the correct density to be 4.75 g/cm3. Which of the following statements represents the best analysis of the data? a) Bud's results have much greater accuracy than precision. b) Bud's results have much greater precision than accuracy. c) Bud's results have high accuracy and high precision. d) Bud's results have low accuracy and low precision. e) Bud's equipment is faulty.
Bud's results have much greater accuracy than precision.
Select the best statement. a) Chemical changes provide the only valid basis for identification of a substance. b) Chemical changes are easily reversed by altering the temperature of the system. c) Chemical changes always produce substances different from the starting materials. d) Chemical changes are associated primarily with extensive properties. e) Chemical changes are accompanied by changes in the total mass of the substances involved.
Chemical changes always produce substances different from the starting materials.
Heinrich Rudolf Hertz
Discovered radio waves; unit of frequency named after him
E = n h v
E is the energy of the radiation v is its frequency n is a positive integer (1, 2, 3 and so on) called a quantum number h = 6.626 x 10-34 Js (planck's constant
Thomsons's "Plum Pudding" Atomic Model showed that...
Electrons are negatively charged particles. But matter is neutral, so atoms must also contain a positively charged component
As chief chemist at Superior Analytical Products (SAP) you must design an experiment to determine the density of an unknown liquid to three (3) significant figures. The density is of the order of 1 g/cm3. You have approximately 7 mL of the liquid and only graduated cylinders and balances are available for your use. Which of the following combinations of equipment will allow you to meet but not exceed your goal? a) Graduated cylinder with ±0.1 mL uncertainty; balance with ±0.1 g uncertainty b) Graduated cylinder with ±0.01 mL uncertainty; balance with ±0.1 g uncertainty c) Graduated cylinder with ±0.01 mL uncertainty; balance with ±0.01 g uncertainty d) Graduated cylinder with ±0.001 mL uncertainty; balance with ±0.001 g uncertainty e) Graduated cylinder with ±0.1 mL uncertainty; balance with ±0.001 g uncertainty
Graduated cylinder with ±0.01 mL uncertainty; balance with ±0.01 g uncertainty
What happened in 5th Century B.C?
Greek philosophers propose matter composed of small, finite particles called atomos (meaning indivisible)
Random Error
In the absence of systematic error, produces values that are higher and lower than the actual value
Kelvin to Celsius
K-273
Celsius to Kelvin
K=C+273
Precision
Refers to reproducibility or how close the measurements are to one another
The Electromagnetic Spectrum
We perceive different wavelengths (or frequencies) of visible light as different colors, red ( = 750 nm) to violet ( = 400 nm).
angle of refraction.
When a wave strikes a boundary (say between air and water) at any angle other than 90°, the change in speed causes a change in direction.
Law of Multiple Proportions
When two elements react to form more than one compound, a fixed mass of one element will react with masses of the other element in a ratio of small, whole numbers
cathode ray
a stream of electrons produced at the negative electrode (cathode) of a tube containing a gas at low pressure
atomic mass unit
a unit of mass that describes the mass of an atom or molecule
Diffraction
a wave striking the edge of an object will bend around it.
At a pressure of one billionth (10-9) of atmospheric pressure, there are about 2.7 ´ 1010 molecules in one cubic centimeter of a gas. How many molecules is this per cubic meter? a) 2.7 ´ 10x16 b) 2.7 ´ 10x14 c) 2.7 ´ 10x12 d) 2.7 ´ 10x8 e) 2.7 ´ 10x4
a) 2.7 ´ 10x16
Element
consists of only one type of atom, which has characteristic mass and other properties
Compound
consists of atoms of two or more elements combined in whole number ratios
polychromatic
(Greek "many colors") light - light consisting of many wavelengths.
monochromatic
(Greek "one color") light- light consisting of a single wavelength.
Freezing point in Celsius
0
Kelvin absolute zero
0 K
How many moles of pyridine (C5H5N) are contained in 3.13 g of pyridine (Molar mass 79.10 g/mol)?
0.0396 mol
The result of (3.8621 ´ 1.5630) - 5.98 is properly written as Question options: a) 0.06 b) 0.056 c) 0.0565 d) 0.05646 e) 0.056462
0.06
The average distance from Earth to the Sun is 150 megameters. What is that distance in meters? a) 1.5 ´ 108 m b) 1.5 ´ 103 m c) 1.5 ´ 106 m d) 1.5 ´ 10-6 m e) 1.5 ´ 105 m
1.5 ´ 108 m
Select the best statement. a) Physical changes may be reversed by changing the temperature. b) Physical changes alter the composition of the substances involved. c) Physical properties are not valid characteristics for identifying a substance. d) Physical properties are mostly extensive in nature. e) Physical changes are usually accompanied by chemical changes.
Physical changes may be reversed by changing the temperature.
black body radiation
an object the absorbs all electromagnetic radiation that falls on it. Classical physics predicts that a _______ will produce a continuous spectrum of visible light if it is heated to very high temperatures
Which of the following is a chemical change? a) boiling of water b) condensing water vapor into rainfall c) melting wax d) carving a piece of wood e) broiling a steak on a grill
broiling a steak on a grill
Isomers
compounds with same chemical formula but different molecular structures
Given that 1 inch = 2.54 cm, 1 cm3 is equal to a) 16.4 in3 b) 6.45 in3 c) 0.394 in3 d) 0.155 in3 e) 0.0610 in3
e) 0.0610 in3
diffraction pattern
generated when light passes through adjacent slits.
Refraction
light of a given wavelength travels at different speeds through different transparent media - vacuum, air, quartz, water, etc.
threshold frequency
light shining on the metal plate must have a minimum frequency, or no current flows AND different metals have different minimum frequencies.
Water vapor is less dense than ice because a) molecules in the gas phase are in constant motion. b) molecules in the gas phase have more potential energy than in solids. c) molecules in the gas phase have more kinetic energy than in solids. d) gaseous molecules have less mass. e) molecules in the gas phase have more space between them than in solids.
molecules in the gas phase have more space between them than in solids.
Protons
positively charged particles, reside in the nucleus
How did Thomson establish that cathode rays were composed of negative particles?
showed experimentally that the cathode ray was deflected by electric fields away from the negative electrode and toward the positive electrode.
structural formula
shows how the atoms are connected in the molecule ex: ball-and-stick , space-filling models
mole
the SI base unit used to measure the amount of a substance
photoelectric effect
the flow of electric current when monochromatic light falls on a metal plate
amplitude
the height of the crest (or the depth of the trough). Measure of the strength of a wave's electric and magnetic fields. Also related to what we perceive as light intensity.
molar mass (M)
the mass per mole of its entities (atoms, molecules or formula units)
Chemistry Definition
the study of the composition, structure, and properties of matter, the processes that matter undergoes, and the energy changes that accompany these processes
mass number (A)
the sum of the number of neutrons and protons in an atomic nucleus
Hertz
the unit of frequency, equal to one cycle per second
atomic mass
weighted average mass of its naturally occurring isotopes