Chemistry Final
5.1 What is the Lewis symbol for I−?
.. - : I : ..
5.1 What is the Lewis symbol for As^3−?
.. 3- : As : ..
4.3 Hydrogen sulfide gas (H2S) is a highly toxic gas that is responsible for the smell of rotten eggs. The volume of a container of hydrogen sulfide is 44.2mL. After the addition of more hydrogen sulfide, the volume increases to 98.5mL under constant pressure and temperature. The container now holds 1.97×10−3mol of the gas. How many grams of hydrogen sulfide were in the container initially? Give your answer in three significant figures.
0.03013g
4.3 A container holds 3.58×10−3mol of the noble gas krypton. After the addition of 5.61×10−3mol of krypton, the volume of the container increases under constant temperature and pressure to 0.206L. What was the initial volume of the container?
0.0802L
4.3 Sulfur hexafluoride is a non-toxic gas that is used to trace airflow in buildings. A 12.2Lcontainer of sulfur hexafluoride contains 0.547mol of gas. More sulfur hexafluoride is added to the container to increase its volume to 17.5L, while the temperature and pressure remain constant. How many additional moles of sulfur hexafluoride gas were added to the container?
0.238mol
4.3 Chlorine gas is held in a container with volume of 1.15L. The container initially held 3.53×10−2mol of chlorine gas, but after some of the gas was removed to carry out a reaction, the volume decreased to 0.790L while the temperature and pressure remained constant. How many grams of chlorine gas were removed from the container? The molar mass of chlorine gas (Cl2) is 70.9gmol. Give your answer in three significant figures.
0.783g
4.3 0.23mol of a gas fills a volume of 0.550L. Additional gas was forced into the container under conditions of constant temperature and pressure, and as a result the container expanded to a volume of 2.20L. How many moles of gas are in the container after the expansion? Round the answer to two decimal places
0.92mol
5.3 How many electron pair geometries are there for an atom with two electron pairs and no lone pairs?
1
4.3 A container initially holds 5.67×10−2mol of propane and has a volume of V1. The volume of the container was increased by adding an additonal 2.95×10−2mol of propane to the container, so that the container has a final volume of 1.93L. If the temperature and pressure are constant, what was the initial volume of the container, V1?
1.27L
4.3 A container with 3.00 moles of gas has a volume of 60.0 L. With a temperature at 400.K, what is the pressure in atm?
1.6412 atm
4.3 A container initially holds 1.24mol of hydrogen gas and has a volume of 27.8L. Hydrogen gas was added to the container, and the final volume increased to 40.6Lwhile the temperature and pressure remained constant. How many moles of hydrogen gas are in the container?
1.81 mol
5.2 A trigonal planar molecule will have bond angles of __________.
120 degrees
4.3 Helium is used to inflate a weather balloon from an initial volume of 2,280L to a final volume of 5,710L under constant temperature and pressure. The final volume contains 255mol of helium. How many moles of helium were added to the balloon?
153mol
4.3 Radon is a radioactive noble gas that can sometimes be found in unventilated basements. A sample of 1.35×10−4mol of radon gas is held in a container with a volume of 3.03mL. A quantity of radon gas is added to the container, which is then found to have a volume of 7.79mL at the same temperature and pressure. How many moles of radon were added to the container?
2.12×10^−4mol
4.2 A sample of oxygen at 300 torr and constant volume cools from 27∘C to −73∘C. What will be the final pressure?
200 torr
4.3 Give the numeric value in units of Lmol for the standard molar volume of an ideal gas at STP with the accuracy of one digit after the decimal point.
22.4L/mol
4.3 What is the value for a temperature of 298.15K in ∘C?
25∘C
4.3 A planet has a surface temperature of 95.0K and an atmospheric pressure of 1.60 atm. If 4.87 L of atmosphere has a mass of 28.6 g, what is the average molar mass of the atmosphere?
28.6 g/mol
5.2 A molecule with linear geometry but five electron regions has ______ lone pairs.
3
5.3 A molecule with linear geometry but five electron regions has ______ lone pairs.
3
4.3 Calculate the pressure in bar of 2520 moles of hydrogen gas stored at 27∘C in the 180 L storage tank of a modern hydrogen-powered car.
350 bar
5.2 How many molecular geometries are possible for a compound that has a central atom with five regions of electron density (trigonal bipyramidal electron pair geometry)?
4
4.3 A researcher studying ozone (O3) fills a plastic bag with ozone and finds that it contains 2.01g of ozone and has a volume of 0.938L. The bag is then filled with additional ozone to make a volume of 2.34L at the same temperature and pressure. How many grams of ozone are now in the bag? The molar mass of ozone is 47.997 g/mol.
5.01g
4.3 A vapor has a mass of 0.846 g, a volume of 354 mL, a pressure of 752 torr, and a temperature of 100.00∘C. What is the molar mass of the vapor?
74.0g/mol
4.3 A container holds 3.41×10−3mol of carbon dioxide (CO2). After the addition of 8.41×10−4mol of carbon dioxide, the volume of the container increases to 95.2mL, with the temperature and pressure remaining constant. What was the initial volume of the container? Give your answer in three significant figures.
76.4mL
4.2 A balloon has a volume of 2.3L at 25.00∘C. Upon increasing the temperature, the balloon expands to 2.7 L. What is the temperature at this increased volume?
76.85∘C
4.2 How much more pressure does a 250lb person exert on the ground than a 120lb person if they are both standing on one foot with area 16in^2?
8.1 lb/in^2
4.2 A gas in a sealed container has an initial pressure of 125 kPa at 25.0∘C. If the pressure is increased to 150.0 kPa, what will the new temperature be?
84.6∘C
4.3 Which of the following represents standard pressure? A. 1 atm B. 101.325 atm C. 1 kPa D. 101.325 kPa
A. 1 atm D. 101.325 kPa
4.3 Which of the following represents STP? Select all that apply. A. 1atm and 273.15K B. 101.325kPa and 273.15K C. 1atm and 0∘C D. 101.325kPa and 0∘C
A. 1atm and 273.15K B. 101.325kPa and 273.15K C. 1atm and 0∘C D. 101.325kPa and 0∘C
4.1 Air pressure at sea level is equal to: (select all that apply) A. 760 torr B. 1 atmosphere C. 101,325 pascals D. 2 bar
A. 760 torr B. 1 atmosphere C. 101,325 pascals
4.3 The ideal gas law displays the relationship in which of the following? A. Amonton's Law B. Charle's Law C. Boyle's Law D. Avogadro's Law
A. Amonton's Law B. Charle's Law C. Boyle's Law D. Avogadro's Law
4.3 Why is it important to know gas properties at STP?
A. Because comparison of properties is possible only if the properties are reported against a standard temperature and pressure. B. In order to know that exactly one mole of an ideal gas has a volume of 22.4L.
5.3 Which of the following has the largest dipole moment? A. NCl3 B. BF3 C. CO2 D. CF4
A. NCl3
4.3 What is true for ideal gases at STP conditions? A. The standard molar volume is 22.4L. B. All gases have the same mass. C. All gases have the same reactivity. D. One mole of any ideal gas has the same volume.
A. The standard molar volume is 22.4L D. One mole of any ideal gas has the same volume
5.2 Which of the following is a step in predicting electron pair geometry and molecular structure using VSEPR theory? Select all that apply. A. count the number of regions of electron density around the central atom B. write the Lewis structure of the molecule C. use the number of lone pairs to determine the molecular structure D. identify the electron-pair geometry based on the number of regions of electron density
A. count the number of regions of electron density around the central atom B. write the Lewis structure of the molecule C. use the number of lone pairs to determine the molecular structure D. identify the electron-pair geometry based on the number of regions of electron density
4.3 Which of the following correctly represents the standard conditions for temperature and pressure (STP)? A. zero degrees Celsius and one atmosphere B. room temperature and one atmosphere C. zero degrees Celsius and 1kPa D. room temperature and 100kPa
A. zero degrees Celsius and one atmosphere
4.3 Which of the following represents the conditions of standard temperature and pressure (STP)? A.25∘C and 1kPa B. 0∘C and 101.325kPa C. 75∘F and 1atm D. 298.15K and 101.325atm E. 273.15K and 1atm
B. 0∘C and 101.325kPa E. 273.15K and 1atm
4.1 Pressure is inversely proportional to which of the following, assuming all other variables are constant? A. Force B. Area C. Both force and area D. Neither force or area
B. Area
4.1 Atmospheric pressure is equivalent to what object resting on your thumbnail? A. Feather B. Bowling Ball C. Grain of Sand D. Elephant
B. Bowling Ball
4.3 What are the units for the ideal gas constant R when the temperature is in kelvin, the volume is in liters, and the pressure is in atmospheres? A. L atm mol K^-1 B. L atm mol^−1 K^-1 C. L atm^−1 mol^−1 K^-1 D. mol K L^−1 atm^−1
B. L atm mol^−1 K^-1
5.3 Which molecule will have a net dipole? A. CO2 B. SO2 C. CH4 D. BF3
B. SO2
5.3 Which of the following molecules have net dipole moments? A. CS2 B. SeS2 C. PCl3 (P is the central atom) D. ClNO (N is the central atom)
B. SeS2 C. PCl3 (P is the central atom) D. ClNO (N is the central atom)
4.2 Gay-Lussac's law assumes that __________. A. The temperature is held constant B. The volume is held constant C. The number of moles is held constant D. The force is held constant
B. The volume is held constant C. The number of moles is held constant
4.1 Which unit of pressure is equivalent to mm Hg? A. Atmospheres B. Torr C. Pascals D. Kilopascals
B. torr
4.2 If the pressure of a gas is kept constant and the temperature (in Kelvin) is cut in half, the volume will __________.
Be cut in half
4.1 Which of the following represents the smallest pressure? A. 1 bar B. 1 millibar C. 1 Pa D. 1 kPa
C. 1 Pa
4.1 Air pressure at sea level is equal to: A. 101,325 torr B. 760 bar C. 14.7 psi D. All of the above
C. 14.7 psi
4.1 What method of walking would apply the least amount of pressure on a surface? A. Tip-toeing B. Walking Normally C. Crawling on all fours D. These all apply the same amount of pressure
C. Crawling on all fours
4.2 Charles's law is described by which of the following equations? A. V=kT B. (V/T)=k C. (V1/T1)=(V2/T2) D. All of the above
D. All of the above
4.2 Which is a correct way of stating Boyle's law? A. P=k*(1/V) where k is a constant B. PV=k where k is a constant C. P1V1=P2V2, where the indices 1 and 2 corresponded to different states of the same gas sample D. All of the above
D. All of the above
5.3 Which molecule will have no net dipole? A. CH3Cl B. CH2Cl2 C. CHCl3 D. CCl4
D. CCl4
5.2 In which molecule are the electron-pair geometry and molecular shape of the same type? A. SO2 B. H2O C. NH3 D. CO2
D. CO2
5.1 Which molecule will have a double bond? A. CO B. CCl4 C. OF2 D. H2CO
D. H2CO
5.3 Use the figure provided to determine which of the following has bonds with the greatest bond-polarity. A. HCl B. NO2 C. NH3 D. H2O
D. H2O
4.2 For an ideal gas, volume and temperature are __________ proportional.
Directly
5.2 Lone pairs present in trigonal bipyramidal electron-pair geometry always occupy which position?
Equatorial
4.3
Gas Laws: Ideal Gas Laws
4.2
Gas Laws: Pressure, Temperature, Volume
4.1
Gas Pressure
4.2 Assuming the temperature and the amount of gas are held constant, a plot of volume vs. pressure will give a:
Hyperbola
4.2 Under conditions of constant temperature and amount of substance, a plot of pressure vs. volume for an ideal gas will result in __________.
Hyperbolic Relationship
4.2 Pressure and volume of an ideal gas are __________.
Inversely Proportional
5.1
Lewis Structures
5.3
Molecular Geometry and Polarity
5.3 Which atom(s) in the molecule CH3OCH3 will display tetrahedral electron-pairgeometry?
O and C
5.1 When drawing the Lewis structure for a molecule, after drawing the skeletal structure and distributing all of the electrons around the terminal atoms, what actions should be taken if the central atom does not have a complete octet?
Rearrange lone pairs of electrons from the outer atom(s) to form double or triple bonds to the central atom.
4.3 Although standard pressure is defined as 1atm, other units of pressure can also be used. It is common to report standard pressure using SI (standard international) units. What is the abbreviation for the SI unit of pressure?
The SI unit of pressure is the pascal, abbreviated as Pa. Standard pressure is defined as 1atm or 1.01325×105Pa in SI units.
4.3 Which of the following best explains why gases deviate from ideal behavior at high density?
The ideal gas law assumes that the gas molecules do not interact. At higher densities, the molecules are closer on average and may experience attractive or repulsive forces that cause the behavior to deviate from ideal.
5.3 Which of the following must be true if a nitrogen in a compound displays a tetrahedral molecular geometry?
The nitrogen atom must form four bonds.
5.2
VSEPR Theory
5.3 The net dipole of a molecule is always:
a combination of the individual bond dipoles
5.3 What will be the molecular structure surrounding a nitrogen atom in a molecule that has a double bond, a single bond, and a lone pair?
bent
5.2 According to VSEPR theory, electrons in the valence shell of a central atom form __________.
both lone pairs and bonding pairs of electrons
5.1 A Lewis symbol with no dots must be a:
cation
5.2 Lewis structures are limited because they do not display the __________.
correct bond angles in the molecule
5.1 When drawing a Lewis structure, the first step is to:
determine the number of valence electrons
5.2 VSEPR theory considers which of the following?
electron-pair repulsions
5.3 The greater the electronegativity difference, the more the bond will exhibit:
ionic character
5.3 When illustrating bond dipoles, vectors point from the ________ electronegative atom to the _______ electronegative atom.
less, more
4.3 mRT/PV allows us to determine:
molar mass of a gas
5.1 Electrons on a Lewis symbol will be arranged:
one on every side before placing a second on any side
5.3 An electrically charged object can be used to attract:
polar molecules
5.3 In an electric field, polar molecules align with the ______ toward the negative plate and the ______ toward the positive plate.
positive end, negative end
5.2 Which of the following is NOT a molecular structure that can be exhibited by a molecule with tetrahedral electron-pair geometry?
see-saw
5.2 What is the molecular structure of IF5?
square pyramidal
5.1 When drawing Lewis structures, which atoms must receive lone pairs first?
terminal atoms
5.3 Why does water have a net dipole while carbon dioxide does not?
the bond dipoles in carbon dioxide cancel each other out
5.2 The molecular structure of a molecule will differ from its electron-pair geometry if:
the central atom has at least one lone pair
5.2 What is the electron pair geometry of SF4?
trigonal bipyramidal
5.2 What will be the electron-pair geometry of XeF2?
trigonal bipyramidal
5.3 What will be the electron-pair geometry for a molecule with five regions of electron density?
trigonal bipyramidal
5.3 Which spatial orientation will involve more than one bond angle value?
trigonal bipyramidal
5.3 What can be used to represent bond dipole moments?
vector
5.3 In the PF5 molecule, what is the geometry of the bond dipole for one PF bond?
vector pointing toward F
4.3 Avogadro's Law states that for an ideal gas:
volume and moles are directly proportional
4.3 Under what condition does the volume of the ideal gas approach zero?
when the temperature approaches 0 K
5.3 The magnitude of a bond dipole moment is represented by the Greek letter mu (μ)and is a function of the magnitude of the partial charges (Q), and the distance between the charge (r). Which of the following equations accurately represents bond dipole moment?
μ=Qr
4.2 A 3.00 L tank of helium gas has an initial pressure of 1.20 atm. When the temperature changes to 37.00∘C, the gas has a pressure of 2.50 atm. What is the initial temperature in units of ∘C?
−124∘C
4.3 An ideal gas is held in a rigid container at temperature of 201∘C. Upon cooling the gas, the pressure decreases by a factor of 2.0, while the volume and the amount of gas remain constant. What must be the final temperature of the gas?
−36∘C
