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WorksheetsExamen 2
Total questions: 31
Worksheet time: 8hrs 45mins
One of the frequencies used to transmit and receive cellular telephone signals in the United States is 850 MHz. What is the wavelength in meters of these radio waves?
0.353 m = 35.3 cm
0.356 m = 35.6 cm
0.300 m = 30.0 cm
0.253 m = 25.3 cm
The microwaves in an oven are of a specific frequency that will heat the water molecules contained in food. (This is why most plastics and glass do not become hot in a microwave oven-they do not contain water molecules.) This frequency is about 3 × 10 9 Hz. What is the energy of one photon in these microwaves?
2 x 10^-24 J
5 x 10^-15 J
10 x 10^-24 J
15 x 10^-3 J
Calculate the threshold energy in kJ/mol of electrons in aluminum, given that the lowest frequency photon for which the photoelectric effect is observed is 9.87 × 10 14 Hz.
3.4 kJ/mol
304 kJ/mol
325 kJ/mol
394 kJ/mol
Early researchers were very excited when they were able to predict the energy of an electron at a particular distance from the nucleus in a hydrogen atom. If a spark promotes the electron in a hydrogen atom into an orbit with n = 3, what is the calculated energy, in joules, of the electron?
−5.421 × 10 −19 J
−2.421 × 10 −19 J
−421 × 10 −19 J
34.9 × 10 −19 J
What is the energy in joules and the wavelength in meters of the photon produced when an electron falls from the n = 5 to the n = 3 level in a He + ion (Z = 2 for He+ )?
6.198 × 10 –19J; 3.780 × 10 −7m
7.342× 10 –19J; 3.205 × 10 −7m
6.198 × 10 –19J; 3.205 × 10 −7m
6 × 10 –19J; 205 × 10 −7m
If an electron travels at a velocity of 1.000 × 10 7 m s –1 and has a mass of 9.109 × 10 –28 g, what is its wavelength?
7.274 × 10 −11 m
7.458 × 10 −11 m
2.374 × 10 −11 m
7.594 × 10 −11 m
What is the hybridization of the selenium atom in SeF4 ?
sp3d hybridized
sp hybridized
sp2d hybridized
spd hybridized
Acetic acid, H3 CC(O)OH, is the molecule that gives vinegar its odor and sour taste. What is the hybridization of the two carbon atoms in acetic acid?
H3C, sp3d; C(O)OH, sp2
H3C, sp3; C(O)OH, sp2d
H3C, sp; C(O)OH, sp3d
H3C, sp3; C(O)OH, sp2
Another acid in acid rain is nitric acid, HNO3 , which is produced by the reaction of nitrogen dioxide, NO2 , with atmospheric water vapor. What is the hybridization of the nitrogen atom in NO2 ? (Note: the lone electron on nitrogen occupies a hybridized orbital just as a lone pair would.)
sp3d
sp3
sp2
sp
The main component of air is N2 . From the molecular orbital diagram of N2 , predict its bond order and whether it is diamagnetic or paramagnetic.
N 2has a bond order of 5 and is paramagnetic
N 2has a bond order of 3 and is diamagnetic
N 2has a bond order of 5 and is diamagnetic
N 2has a bond order of 3 and is paramagnetic
The main component of air is N2 . From the molecular orbital diagram of N2 , predict its bond order and whether it is diamagnetic or paramagnetic.
N 2has a bond order of 5 and is diamagnetic
N 2has a bond order of 5 and is paramagnetic
N 2has a bond order of 3 and is diamagnetic
N 2has a bond order of 3 and is paramagnetic
A typical barometric pressure in Kansas City is 740 torr. What is this pressure in atmospheres, in millimeters of mercury, in kilopascals, and in bar?
0.974 atm; 740 mm Hg; 98.7 kPa; 0.987 bar
0.900 atm; 730 mm Hg; 10.7 kPa; 0.790 bar
0.74 atm; 77 mm Hg; 9.7 kPa; 0.680 bar
0.89 atm; 712 mm Hg; 57 kPa; 987 bar
Calculate the height of a column of water at 25 °C that corresponds to normal atmospheric pressure. The density of water at this temperature is 1.0 g/cm3 .
12.7 m
1.3 m
13.2 m
10.3 m
The pressure of a sample of gas is measured with a closed-end manometer. The liquid in the manometer is mercury. Determine the pressure of the gas in:
(a) torr
(b) Pa
(c) bar
(a) ~145 torr; (b) ~24,000 Pa; (c) ~0.33 bar
(a) ~150 torr; (b) ~20,000 Pa; (c) ~0.20 bar
(a) ~230 torr; (b) ~27,000 Pa; (c) ~0.78 bar
(a) ~189 torr; (b) ~26,000 Pa; (c) ~0.45 bar
The pressure of a sample of gas is measured at sea level with an open-end Hg manometer, as shown to the right. Determine the pressure of the gas in:
(a) mm Hg
(b) atm
(c) kPa
(a) 642 mm Hg; (b) 0.845 atm; (c) 85.6 kPa
(a) 578 mm Hg; (b) 0.354 atm; (c) 83.9 kPa
(a) 470 mm Hg; (b) 0.89 atm; (c) 457 kPa
(a) 628 mm Hg; (b) 0.436 atm; (c) 26.6 kPa
How many unpaired electrons would be present on a Be 2 2− ion? Would it be paramagnetic or diamagnetic?
Two, paramagnetic
two, diamagnetic
One, paramagnetic
Four, diamagnetic
A sample of nitrogen, N2 , occupies 45.0 mL at 27 °C and 600 torr. What pressure will it have if cooled to –73 °C while the volume remains constant?
400 torr
411 torr
445 torr
437 torr
A sample of oxygen, O2 , occupies 32.2 mL at 30 °C and 452 torr. What volume will it occupy at –70 °C and the same pressure?
13.6 mL
23.9 mL
36.4 mL
21.6 mL
What is the volume of a sample of ethane at 467 K and 1.1 atm if it occupies 405 mL at 298 K and 1.1 atm?
243 mL
635 mL
605 mL
255 mL
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.
330 bar
350 bar
457 bar
438 bar
A sample of ammonia is found to occupy 0.250 L under laboratory conditions of 27 °C and 0.850 atm. Find the volume of this sample at 0 °C and 1.00 atm.
0.587 L
0.268 L
0.347 L
0.193 L
What is the density of molecular hydrogen gas at 17.0 °C and a pressure of 760 torr?
d = 0.0780 g/L
d = 0.0847 g/L
d = 0.0578 g/L
d = 0.0455 g/L
A sample of phosphorus that weighs 3.243 × 10 −2 g exerts a pressure of 31.89 kPa in a 56.0-mL bulb at 550 °C. What are the molar mass and molecular formula of phosphorus vapor?
543 g/mol P4
234 g/mol P4
124 g/mol P4
100 g/mol P4
A 5.73-L flask at 25 °C contains 0.0388 mol of N2 , 0.147 mol of CO, and 0.0803 mol of H2 . What is the total pressure in the flask in atmospheres?
1.137 atm
3.953 atm
8.912 atm
4.089atm
What is the pressure of a mixture of 0.200 g of H2 , 1.00 g of N2 , and 0.820 g of Ar in a container with a volume of 2.00 L at 20 °C?
5.21 atm
2.65 atm
1.87 atm
3.78 atm
A sample of oxygen collected over water at a temperature of 29.0 °C and a pressure of 764 torr has a volume of 0.560 L. What volume would the dry oxygen have under the same conditions of temperature and pressure?
0.237 L
0.583 L
0.346 L
0.587 L
An acetylene tank for an oxyacetylene welding torch provides 9340 L of acetylene gas, C2 H2 , at 0 °C and 1 atm. How many tanks of oxygen, each providing 7.00 × 10 3 L of O 2 at 0 °C and 1 atm, will be required to burn the acetylene?
2C 2 H 2 + 5O 2 ⟶ 4CO 2 + 2H 2 O
8.00 tanks (2.4 × 10 4 L)
4.45 tanks (7.80 × 10 4 L)
3.34 tanks (2.34 × 10 4 L)
3.34 tanks (3.90 × 10 4 L)
What volume of O2 (g) measured at 25 °C and 760 torr is required to react with 17.0 L of ethylene, C2 H4 (g), measured under the same conditions of temperature and pressure? The products are CO 2 and water vapor.
51.0 L
34.0 L
26.8 L
10.5 L
Sulfur dioxide is an intermediate in the preparation of sulfuric acid. What volume of SO 2 at 343 °C and 1.21 atm is produced by burning l.00 kg of sulfur in excess oxygen?
1.30 × 10 3 L
2.87 × 10 3 L
14.7 × 10 3 L
7.10 × 10 3 L
Water rises in a glass capillary tube to a height of 8.4 cm. What is the diameter of the capillary tube?
diameter = 0.36 mm
diameter = 0.49 mm
diameter = 0.16 mm
diameter = 0.67 mm
How much heat is required to evaporate 100.0 g of liquid ammonia, NH3 , at its boiling point if its enthalpy of vaporization is 4.8 kJ/mol?
5.8 kJ
28 kJ
50 kJ
3.4 kJ
