CHEM TEST 1 REVIEW
The process of the evolution of species as described by Darwin is best thought of as
Theory
Which element has the ground state electron configuration [Xe]6s²4f¹⁴5d⁴?
W
Which of the following is a step that is NOT in the scientific method?
modifying laws
Which of the following pairs represent isotopes?
²⁸Si and ²⁹Si
Which of the following would be an isotope of ¹⁴N?
¹⁶N
Red light has a _____ frequency and a _____ wavelength than ultraviolet rays.
lower, longer
Which of the following metric prefixes corresponds to 10⁶? A) centi- B) kilo- C) mega- D) micro- E) milli-
mega-
Which of the following groups of elements tend to form cations?
metals
Which of the following metric prefixes corresponds to 10⁻³? A) centi- B) kilo- C) mega- D) micro- E) milli-
milli-
How many electrons in an atom can have the following quantum numbers? n = 4, ℓ = 2, mℓ = -2, ms = +½
1
If n = 2, what is the maximum allowed value for ℓ?
1
Which of the following contains the most moles of atoms?
1 g of helium
For each of the following atoms or ions, determine the correct ground state electron configuration. Tin, Sn Sn⁴⁺ Iodine, I I⁻
1- [Kr]5s²4d¹⁰5p² 2- [Kr]4d¹⁰ 3- [Kr]5s²4d¹⁰5p⁵ 4- [Kr]5s²4d¹⁰5p⁶
What is the frequency of a photon if the energy is 7.27 × 10⁻¹⁹ J? (h = 6.626 × 10⁻³⁴ J • s)
1.10 × 10¹⁵ s⁻¹
Determine the number of atoms of O in 22.3 moles of Al₂(CO₃)₃.
1.21 × 10²⁶ atoms
For a hydrogen atom, calculate the wavelength of light (in m) that would be emitted for the orbital transition of n(initial) = 2 to n(final) = 1. Submit an answer to four significant figures. The Rydberg constant is 1.09678 x 10⁷ m⁻¹.
1.216 × 10⁻⁷ m
How many atoms of vanadium are in 1.28 grams of vanadium?
1.51 × 10²² atoms V.
What is the energy of a mole of photons that have a wavelength of 701 nm? (h = 6.626 × 10⁻³⁴ J • s and c = 3.00 × 10⁸ m/s)
1.7 × 10⁵ J
A student is determining the density of an unknown metal with a mass of 56.5 g. The student partially fills a graduated cylinder with water and measures the volume of the water by itself as 54.8 mL. The student then adds the metal to the water and measures the new volume as 87.3 mL. What is the density, in g/mL, of the metal?
1.74 g/mL
What is the energy of light that must be absorbed by a hydrogen atom to transition an electron from n = 3 to n = 6?
1.82 × 10⁻¹⁹ J
How many milliliters are in a liter?
1000 mL
You were given a dose of 500 mg rather than 500 μg of a drug. How much more of the drug did you receive?
1000 times more
Which of the following options correctly rounds 126.006 to two significant figures?
130
Determine the molar mass of RbNO₃
147.47 g/mol
The chemical formula of caffeine is C₈H₁₀N₄O₂. How many N atoms are in 4 molecules of caffeine?
16
The ground state electron configuration of an Al atom is
1s²2s²2p⁶3s²3p¹
What is the electron configuration of K⁺?
1s²2s²2p⁶3s²3p⁶
Which of the following represents the electron configuration of P³⁻?
1s²2s²2p⁶3s²3p⁶
What is the electron configuration of Co²⁺?
1s²2s²2p⁶3s²3p⁶3d⁷
The ground state electron configuration of a Se atom is
1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁴
Calculate the effective nuclear charge on a valence electron in a calcium atom
2
What is the maximum number of electrons that can have the following set of quantum numbers? n = 2, ℓ = 1, mℓ = 1.
2
When an electron in excited energy level drops to a lower energy level, a photon is emitted. If the electron is dropping to n=1, which transition will emit the longest wavelength? n=______ to n=1
2
How many moles of hydrogen are in 3.06 × 10⁻³ g of glycine, C₂H₅NO₂?
2.04 × 10⁻⁴ mol H.
Platinum has a work function (Φ) of 9.05 × 10⁻¹⁹ J. What is the longest wavelength of light that will cause the ejection of electrons?
2.20 × 10⁻⁷ m
The mass of a piece of metal is 20.7651 grams. When the piece of metal was dropped into a graduated cylinder that had an initial water volume of 5.35 cm³, the total volume was 13.34 cm³. What is the density of the piece of metal in g/cm³?
2.60 g/cm3
Calculate the wavelength in meters of electromagnetic radiation that has a frequency of 1.09 × 10⁸ s⁻¹. (c = 3.00 X 10⁸ m/s)
2.75 m
How many electrons are in a neutral ⁴¹Ca atom?
20
What is the mass number for an atom of mercury containing 80 protons and 121 neutrons?
201
Chlorine exists in nature as a mixture of two stable isotopes, Cl-35 and Cl-37. If the atomic mass of chlorine is given as 35.45 amu, which of the following represents the percent abundance of Cl-37?
23%
Determine the mass, in grams, of 0.450 moles of Mn (1 mol of Mn has a mass of 54.94 g).
24.7 g
What type of light on the electromagnetic spectrum has the highest energy per photon?
Gamma waves
Which element has the electron configuration 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p²?
Ge
You have a 100 gram sample of each of the following metals. Which sample has the smallest volume? A) Aluminum, d = 2.7 g/cm³ B) Gold, d = 19.3 g/cm³ C) Iron, d = 7.86 g/cm³ D) Magnesium, d = 1.74 g/cm³ E) Silver, d = 10.5 g/cm³
Gold, d = 19.3 g/cm³
Which scientist surmised the scientific principle that the position and momentum of an electron cannot be known simultaneously with a high degree of accuracy?
Heisenberg
Which of the following terms describes what a doctor forms when treating patients prior to ordering medical tests?
Hypothesis
Which element has the electron configuration 1s²2s²2p⁶3s²3p⁶4s²3d⁵?
Mn
The element antimony (Sb) has an atomic mass of 121.76 amu. Two naturally occurring isotopes of antimony are ¹²¹Sb (57% abundant) and ¹²³Sb (43% abundant). In a sample of 100 Sb atoms, what is the probability that a single selected atom has a mass of 121.76 amu?
0%
The number 1.44 × 10⁻⁴ when taken out of scientific notation would be
0.000144
Perform this mathematical operation and express the answer to the correct number of significant figures: 0.085631 × 1.32
0.113
Determine the mass in grams of 3.00 × 10²¹ atoms of arsenic. (The mass of one mole of arsenic is 74.92 g.)
0.373 g
How many moles of RbF are in 57.0 grams of RbF?
0.546 mol
An unknown element X has the following isotopes: ²⁵X (80.5% abundant) and ²⁷X (19.5% abundant). What is the average atomic mass in amu of X
25.4 amu
A chemist has a block of copper metal (density is 8.96 g/mL). They drop the metal into a graduated cylinder containing water, and find the volume change is 3.10 mL. What is the mass of the block, in grams?
27.8 g
What is the wavelength (in nm) of a photon if the energy is 7.26 × 10⁻¹⁹ J? (h = 6.626 × 10⁻³⁴ J • s)
273.79 nm
How much money will it cost to drive a school bus 75.0 miles if it gets 6.50 miles per gallon and gas costs $2.459/gallon?
28.37 $
A thermometer reads 18.3 °C. What is the temperature in Kelvin?
291.5 K
How many significant figures does the number 67,200 have?
3
How many molecules are in 50.8 moles of CCl₄?
3.06 × 10²⁵ molecules
The number 3780000 written in scientific notation would be
3.78 × 10⁶
How many grams are in 5.32 × 10²² molecules of CO₂?
3.89 g CO₂.
A chemist has a block of gold metal (density is 19.3 g/mL). They drop the metal into a graduated cylinder containing water, and find the volume change is 1.9 mL. What is the mass of the block, in grams?
36.7 g
How many protons are in an atom of strontium-90?
38
Which of the following orbitals cannot exist?
3f
For which atomic orbital does n = 3 and ℓ = 1?
3p
How many significant figures are in 0.06300
4
How many significant figures does the number 1.006 × 10⁷ have?
4
What is the mass in grams of 7.57 × 10²⁵ molecules of O₂?
4.02 × 10³ g
What is the energy of a photon with a frequency of 7.00 × 10¹⁴ s⁻¹? (h = 6.626 × 10⁻³⁴ J • s)
4.64 × 10⁻¹⁹ J
Calculate the wavelength in meters of electromagnetic radiation that has a frequency of 710.0 kHz. (c = 3.00 X 10⁸ m/s)
422.5 m
What is the wavelength of light (in nm) emitted when an electron transitions from n = 5 to n = 2 in a hydrogen atom?
434 nm
What is the wavelength (in nm) of blue light that has a frequency of 6.69 × 10¹⁴ s⁻¹? (c = 3.00 × 10⁸ m/s)
448.4 nm
In a multi-electron atom, which orbital will have the highest energy? A) 4s B) 4p C) 4d D) 4f E) All are equal
4f
The scattering of sunlight by the mixture of gas molecules in air results in the blue color of the sky. Calculate the energy (in Joules) of a single photon of blue light with a frequency of 7.5 × 10¹⁴ Hz. (h = 6.626 × 10⁻³⁴ J • s)
5.0 × 10⁻¹⁹ J
The density of helium in a balloon is 1.18 g/L. If a balloon holds 2.93 L of He, how many atoms of He are in the balloon?
5.21 × 10²³ atoms
Determine the energy of a photon with a wavelength of 364 nm
5.47 × 10⁻¹⁹ J
Determine the energy of a photon with a wavelength of 361 nm. (h = 6.626 × 10⁻³⁴ J • s and c = 3.00 × 10⁸ m/s)
5.50 × 10⁻¹⁹ J
What is the frequency of green light that has a wavelength of 531 nm? (c = 3.00 x 10⁸ m/s)
5.65 × 10¹⁴ s⁻¹
A photon has a frequency of 8.6 × 10⁸ Hz. What is the energy of this photon?
5.7 × 10⁻²⁵ J
Which of the following numbers contains five significant figures?
50.260
A particular medication dosage is 45.0 mg/kg of body weight. What is the mass in mg of the medication a child weighing 25.1 lb. should receive?
513 mg
What is the mass percentage of Na in NaF?
54.75%
An atom of the isotope ¹³³Cs contains how many protons (p), neutrons (n), and electrons (e)?
55 p, 78 n, 55 e
For an atom of carbon, which ionization will exhibit a very large increase in the energy relative to the preceding ionization?
5th
In a ground state atom of Ar how many electrons total will have the quantum number ℓ = 0?
6
The number 0.00000620 written in scientific notation would be
6.20 × 10⁻⁶
Determine the energy of a photon with a wavelength of 303 nm. (h = 6.626 × 10⁻³⁴ J • s and c = 3.00 × 10⁸ m/s)
6.56 × 10⁻¹⁹ J
If 4.9 kg of CO₂ are produced during a combustion reaction, how many molecules of CO₂ would be produced?
6.7 × 10²⁵ molecules
How many atoms are in 1.2 mol of carbon
7.22 × 10²³ atoms
An unknown element is a mixture of isotopes ¹²⁰X and ¹²²X. The average atomic mass of X is 121.47 amu. What is the percent abundance of ¹²²X?
73.5%
What is the atomic number for an element whose mass number is 180, which contains 106 neutrons per atom?
74
An irregularly-shaped piece of tin (Sn) has a mass of 65.0 grams. What is the volume in cm³ of this piece of tin if its density is 7.30 g/cm³?
8.90 cm³
Determine the number of atoms in 61.0 grams of calcium, Ca. (The mass of one mole of calcium is 40.08 g.)
9.17 × 10²³ atoms
How many hydrogen atoms are in 15 molecules of diborane, B₂H₆?
90
A white powder mixture is placed into water. Some of the powder sinks to the bottom of the container, some rises to the top. The separation of the powder mixture is an example of
A physical change
Which one of the following would have the largest density? A) 56.0 g of a metal with a density of 11.3 g/cm³. B) A sample of metal that occupies 24.7 cm³ and weighs 326 g. C) 250.0 g of a liquid that has a volume of 180.0 mL. D) A 781 g of sample of metal that occupies 74.3 cm³.
A sample of metal that occupies 24.7 cm³ and weighs 326 g
If light has a lot of energy, it will have
A small wavelength
Consider two compounds. Compound A contains 15.7 g of sulfur and 18.6 g of fluorine. Compound B contains 25.4 g of sulfur and 60.2 g of fluorine. What is the mass ratio of fluorine to sulfur in Compound A? What is the mass ratio of fluorine to sulfur in Compound B? For Compound A, the ratio of fluorine to sulfur is 1.18. For Compound B, the ratio of fluorine to sulfur is 2.37. Using the Law of Definite Proportions (also called the Law of Constant Composition), could Compound A and Compound B be the same compound?
A- 1.18 B- 2.37 C- No, because they have different ratios of the same elements
Which color (frequency) of light travels the fastest in a vacuum?
All have the same speed
If you go mini-golfing, in which of these scenarios are you precise but not accurate?
All of your shots are off, but they all go to the same place
Which of the following hypotheses is testable by using the scientific method?
All swans are white
Which postulate(s) of Dalton's atomic theory of matter is/are NOT true?
Atoms of a given element are identical & atoms are indestructible
Write the empirical formula corresponding to B₃N₃H₆?
BNH₂
What scientist proposed that the electron in a hydrogen atom can only have certain energies (i.e., the electron is quantized)?
Bohr
Based on the positions of the following elements on the periodic table, which of them would you expect to form a 3+ cation?
Both scandium and aluminum
Which of the following describes a chemical change involving water? A) H₂O(l) → H₂O(s) B) H₂O(s) → H₂O(g) C) H₂O(l) → H₂(g) + ½O₂(g) D) H₂O(g) → H₂O(l)
C) H₂O(l) → H₂(g) + ½O₂(g)
Glucose is an important biological molecule with the molecular formula C₆H₁₂O₆. What is its empirical formula?
CH₂O
Which of the following is a physical change?
Condensation forms on cold glass
A chemist is trying to identify an unknown metal, and finds that 25.0 cm³ of the substance has a mass of 224.43 g at 20°C. Which of the following metals is it?
Copper, d = 8.98 g/cm³
Which element has the electron configuration 1s²2s²2p⁶3s²3p⁶4s¹3d⁵?
Cr
Which of the following elements has the smallest first ionization energy?
Cs
A molecule has an empirical formula of CH, and its molar mass is known to be 26 g/mol. What is its molecular formula?
C₂H₂
The analysis of a compound shows it contains 5.4 mol C, 7.2 mol H, and 1.8 mol N. What is the empirical formula of the compound?
C₃H₄N
Write the empirical formula corresponding to caffeine, C₈H₁₀N₄O₂.
C₄H₅N₂O
The empirical formula of a covalent compound is CH₂. Which of the following is NOT a possible chemical formula for this compound?
C₆H₁₀
Determine the empirical formula for C₆H₁₄O
C₆H₁₄O
What is the molecular formula of a compound with an empirical formula of CH and a molar mass of 78.1 g/mol?
C₆H₆
Which of the following is an example of an empirical formula?
C₇H₁₄Cl₂
Which of the following quantities is equivalent to 594 mg? A) 0.594 μg B) 5.94 g C) 594,000 kg D) 0.594 g E) 0.00594 kg
D) 0.594 g
Because electron energy levels are quantized, which of the following is true? I) Atomic emission spectra are a series of discrete lines. II) Atomic emission spectra are continuous. III) Electrons may only occupy a discrete set of energy levels. IV) Electrons may occupy a continuous range of energy levels.
E) I and III
Which of the following combinations would form a solution? I) Water and ethanol II) Sand and table salt III) Oxygen and nitrogen IV) Oil and vinegar
E) I and III
Cathode rays are composed of what fundamental particle?
Electrons
Calcium is an example of a(n)
Element
What happens to the energy of a photon if the wavelength is doubled?
Energy is reduced by one-half
Which scientist developed the nuclear model of the atom?
Ernest Rutherford
Rank the following atoms in order of decreasing first ionization energies (i.e., highest to lowest): Li, Be, Ba, F
F > Be > Li > Ba
What is the empirical formula of a compound that contains only iron and oxygen and is 22.27% oxygen?
FeO
An iron-containing compound is 20.1% Fe, 11.5% S, 63.3% O, and 5.1% H. What is the empirical formula for this compound?
FeSO₁₁H₁₄
What element is theoretically the largest of all on the periodic table?
Francium (Fr)
Consider these electron transitions in a hydrogen atom: I. n = 2 → n = 1 II. n = 3 → n = 1 III. n= 1 → n = 4 Which of the electron transitions would release the most energy?
II
Which of the following statements about subatomic particles are true? I. Protons and neutrons have charges of opposite signs but the same magnitude. II. Protons and neutrons have about the same mass. III. A neutral atom always has the same number of neutrons and electrons.
II only
Which of the following statements about subatomic particles are false? I. Some atoms do not have any neutrons. II. Protons and neutrons reside in the nucleus. III. Some atoms do not have any protons
III only
Which one of the following would be a physical property of glucose?
In its pure form, it is a white powder
Which of the following radii comparisons is correct?
In³⁺ < In⁺
Which of the following is an example of an extensive property of copper nugget?
It has a mass of 52.3 g.
Which one of the following is an example of a heterogeneous mixture?
Italian salad dressing
Which of the following is an intensive property of a sample of neon gas?
Its temperature
Which of the following metric prefixes corresponds to 10³? A) centi- B) kilo- C) mega- D) micro- E) milli-
Kilo-
What is the noble gas core in the electron configuration for Ru?
Kr
Which of the following atoms would have the longest de Broglie wavelength, if all have the same velocity?
Li
The law of conservation of mass is best described as which of the following statements? A) The total energy of the universe is constant. B) Matter can neither be created nor destroyed. C) Energy equals mass times the speed of light squared. D) For every action, there is an equal and opposite reaction. E) Mass can only decrease as a result of a chemical reaction.
Matter can neither be created nor destroyed
Which of these ions is isoelectronic to the oxide anion O²⁻?
Mg²⁺
For each of the following ground state electron configurations, determine what is incorrect. N: 1s²2s¹2p³ Si: 1s²2s²2p⁶3s²3p³ Cr: 1s²2s²2p⁶3s²3p⁶4s²3d⁴
N- The configuration is missing an electron in the 2s orbital. Si- The configuration has too many electrons in the 3p orbital. Cr- Cr is an exception and has only 1 electron is the 4s orbital.
Rank the following compounds in order of increasing mass percentage of nitrogen: NO, NO₂, N₂O.
NO₂ < NO < N₂O
A compound containing Na, C, and O is found to have 1.06 mol Na, 0.528 mol C, and 1.59 mol O. What is the empirical formula of the compound?
Na₂CO₃
Valence electrons in which of the following atoms experience the greatest effective nuclear charge (Zeff)?
Ne
Which of the following elements would have a very different electron affinity value compared to the others?
Ne- it is a noble gas
Which of the following is the first step in the scientific method?
Observation
Which following ions share an electron configuration with a noble gas?
O²⁻
Which pair of elements have the same valence electronic configuration of np³?
P and Sb
The nucleus of an atom contains
Protons and neutrons
Which type of electromagnetic radiation has the largest wavelength?
Radio waves
Rank the following atoms in order of decreasing size (i.e., largest to smallest): Rb, F, Mg, B, N
Rb > Mg > B > N > F
Which scientist determined the charge of the electron
Robert Millikan
Which of the following transition metals would be expected to have the smallest atomic radius?
Ruthenium (Ru)
Who developed the equation that allowed the energy of the electron to be described quantum mechanically?
Schrodinger
Gasoline is composed of a variety of different liquid hydrocarbons, which do not separate as time passes. Gasoline is an example of a
Solution
If a hydrogen (H) atom and a helium (He) atom travel at the same speed, which of the following is true about the de Broglie wavelengths of the atoms?
The H atom is about 4 times longer than the He atom.
Which is not one of Dalton's hypotheses of atomic theory?
The atoms of one element are the same as atoms of another element.
Which of the following is an example of an intensive property of a bar gold?
The bar has a density of 19.2 g/mL
The Millikan oil drop experiment determined
The charge of the electron
Photons are shone on a piece of metal and one electron is ejected for each absorbed photon. What happens when the wavelength of light is decreased?
The ejected electrons would have greater kinetic energy.
The cathode ray tube experiment determined
The existence of electrons
Which of the following laws explains the following statement? Acetylene gas, regardless of its method of preparation, always has the same carbon to hydrogen ratio
The law of definite proportions
In two chemical reactions, 4.0 grams of oxygen combine with 3.0 grams of carbon to form one compound, and 8.0 grams of oxygen combine with 3 grams of carbon to form another. This can be explained by
The law of multiple proportions
When methane is completely combusted in oxygen forming carbon dioxide and water, how does the mass of the reactant gases compare to the products?
The masses of the reactants and products are equal.
The atomic mass of germanium (Ge) on the periodic table is 72.630 amu. Which of the following best explains why the atomic mass is a fraction between 72 and 73?
The presence of different isotopes
In the photoelectric effect, if the intensity of light shone on a metal increases, what will happen?
There will be more electrons ejected
Which of these statements is true concerning the following reaction? Na(g) → Na⁺(g) + e⁻
This is an ionization process.
True or false: two electrons can simultaneously occupy the same (n,ℓ,mℓ) orbital.
True
Which of the following has the electron configuration 1s²2s²2p⁶3s²3p⁶3d³?
V²⁺
Light wave A has a greater frequency than light wave B. Which has a greater wavelength?
Wave B
Which of the following is the electron configuration for Ba?
[Xe]6s²
An electron has the following set of quantum numbers: 3, 2, -1, -½. What is the energy level for this electron? What type of orbital is represented by these quantum numbers? Which of the following atoms could have an electron in the ground state with these quantum numbers?
a- 3 b- a d-orbital c- Kr
Positively charged particles of radiation emitted from the decay of radioactive substances are known as
alpha particles
Most early attempts to organize the elements were based on atomic mass. Mendeleev occasionally switched elements so that apparently lighter elements occurred after a heavier element. He did this so that elemental properties properly recurred in the same group. This choice anticipated the discovery of which two features of elements?
atomic number and isotopes
Energy of a photon is ______ proportional to frequency, and _______ proportional to wavelength
directly, inversely
The trend towards smaller atomic radii as one moves to the right in a period is _____.
due to the effective nuclear charge increasing.
Which particle would have the longest de Broglie wavelength traveling with the same velocity?
electron
The net charge on an atom of a given element changes as ______ are added or removed
electrons
Which of the following forms of radiation has the highest frequency?
gamma rays
In the Bohr model of the hydrogen atom, the energy required to excite an electron from n = 2 to n = 3 is _______________ the energy required to excite an electron from n = 3 to n = 4?
greater than
What quantum mechanics principle states that electrons are added to atomic orbitals with the same energy so that each orbital is singularly occupied with electrons having the same spin?
hunds rule
What is observed when a noble gas is heated and the emitted light shone through a prism?
individual lines of varying colors
Rutherford's gold foil experiment determined that
most of the space in an atom is empty except for a concentrated area called the nucleus
Which of the following sets of quantum numbers is not allowed?
n = 2, ℓ = 2, mℓ = 2
Which of the following sets of quantum numbers is not allowed?
n = 4, ℓ = 0, mℓ = -1
Which of the following sets of quantum numbers can describe a 4s electron?
n = 4, ℓ = 0, mℓ = 0
If ℓ = 0, which of the following may be true?
n = 6
In an investigation of the electronic absorption spectrum of a particular element, it is found that a photon having λ = 500 nm provides just enough energy to promote an electron from n = 2 to n = 3. From this information, we can deduce
the difference between the energies of the n = 2 and n = 3 levels.
Effective nuclear charge, Zeff, is defined as
the true nuclear charge minus the charge that is shielded by electrons.
You measured the mass of a dry powder on a balance to be 23.76 g. What would you report as the uncertainty of this measurement?
± 0.01
Which of the following is true concerning ψ²?
ψ² describes the probability of finding an electron in space.