Chem quiz questions

Evaluate the following expression to the correct number of significant figures: 2.34 × 10-2 mL + 1.002 × 10-2 mL + 0.02 mL a. 5. × 10-2 mL b. 5.0 × 10-2 mL c. 5.3 × 10-2 mL d. 5.34 × 10-2 mL e. 5.342 × 10-2 mL

A

How many atoms are there in a 10.0 g sample of aluminum? Note: 1 amu = 1.6606 × 10-24 grams a. 2.23 × 1023 atoms b. 6.15 × 10-25 atoms c. 1.62 × 1026 atoms d. 4.48 × 10-22 atoms e. 2.23 × 1021 atoms

A

How many micrograms are in a kilogram? a. 109 b. 10-9 c. 10-6 d. 106 e. 103

A

Put the following in order of increasing mass. I: beryllium ion, Be2+ II: electron III: neutron IV: tritium, 1 3H a. II < III < IV < I b. II < III < I < IV c. I < IV < III < II d. III < IV < I < II e. IV < III < II < I

A

Sodium and lithium have similar chemical properties because a. they have the same number of valence electrons. b. sodium ion and lithium ion are isoelectronic. c. they are both alkaline earth metals d. a and b e. a and c

A

The atomic weight of hydrogen from the periodic table is 1.0079 amu. From this information, what is the likely approximate isotopic composition of naturally occurring hydrogen on earth? a. mostly protium (no neutrons) b. mostly deuterium (1 neutron) c. mostly tritium (2 neutrons) d. equal amounts of protium, deuterium and tritium e. equal amounts of protium and deuterium, with a lesser amount of tritium

A

Which of the following has exactly 4 significant figures? a. 5.050 × 107 b. 9.7001 c. 0.0020 d. 0.15510 e. 3510

A

Which of the following is equivalent to the volume of a cube that is 100 cm on each side? Note: The volume of a cube is length × width × height. a. 1 kiloliter b. 1 megaliter c. 102 centiliters d. 106 microliters e. 109 milliliters

A

A certain isotope has 17 protons, 18 neutrons, and 18 electrons. The correct symbol for this is: a. 35Ar b. 35Cl- c. 17Cl+ d. 36K2- e. 53I-

B

Convert 3.5 liters to milliliters. a. 3.5 × 10-3 mL b. 3.5 × 103 mL c. 3.5 × 106 mL d. 350000 mL e. 0.00350 mL

B

Convert 5.0 × 10-8 cm to units of Å. Note that 1 Å is exactly 10-10 m. a. 0.50 Å b. 5.0 Å c. 50 Å d. 5.0 × 10-2 Å e. 5.0 × 101 Å

B

How many distinct d-orbitals exist? Remember, the d-block is ten elements wide. a. 3 b. 5 c. 6 d. 10 e. 18

B

Put the following types of electromagnetic radiation in order of increasing energy. I: orange light II: UV radiation III: red light IV: microwaves a. IV < I < II < III b. IV < III < I < II c. I < IV < III < II d. III < IV < I < II e. II < I < III < IV

B

The atomic weight listed for an element in the periodic table is a. the same as the mass number (A) for the element. b. a weighted average of the weights of naturally-occurring isotopes of the element. c. the average of the mass number (A) and the atomic number (Z). d. the mass of an atom with the weight adjusted to reflect loss or gain of electrons. e. the weight of the predominant isotope found on earth.

B

The nucleus is held together by a. electromagnetic radiation. b. nuclear strong force. c. electrostatic attraction. d. gravitational force. e. all of the above

B

What is the approximate mass in amu of 33 atoms of gold-203? a. 5200 amu b. 6700 amu c. 1.1 × 10-19 amu d. 1.1 × 10-20 amu e. 1.0 × 10-23 amu

B

Which is the correct ground state electron configuration for a neutral scandium atom? a. [Ar]4d3 b. [Ar]4s23d1 c. [Ar]3s23p1 d. 1s21p62s22p63s23p3 e. 1s22s22p63s23p64s24d1

B

Which of the following represents a ground state electron configuration? a. 1s ↑↓ 2s ↑↓ 2p ↑ ↑ ↑ 3s ↑ b. 1s ↑↓ 2s ↑↓ 2p ↑↓ ↑↓ ↑ 3s c. 1s ↑↓ 2s ↑ 2p ↑ ↑ ↑ 3s d. 1s ↑ 2s ↑ 2p ↑ ↑ ↑ 3s ↑ e. 1s ↑↓ 2s ↑↓ 2p ↑↓ ↑ ↑ 3s ↑

B

A compound is a liquid at 250°F. Which of the following could be the correct melting point and boiling point for this material? a. 0°C and 100°C b. 390°C and 840°C c. 100°C and 212°C d. -20°C and 120°C e. 130°C and 180°C

C

A single orbital (for example: a d orbital in the 3rd shell or a 2p orbital) has a maximum capacity of a. 2 protons. b. 2 neutrons. c. 2 electrons. d. 6 electrons. e. 10 electrons.

C

How many electrons can occupy the shell having n = 2? a. 2 b. 6 c. 8 d. 18 e. 32

C

Suppose an equal amount of heat is absorbed by different masses of each of the following metals and you discover that the temperature of the magnesium sample changes the most. Which of the following could be a correct statement of the relative masses of the metal samples studied? Au: 0.031 cal/g⋅°C Fe: 0.106 cal/g⋅°C Mg: 0.245 cal/g⋅°C a. mass Mg > mass Au > mass Fe b. mass Mg > mass Fe > mass Au c. mass Au > mass Fe > mass Mg d. mass Au > mass Mg > mass Fe e. mass Fe > mass Mg > mass Au

C

Which is the correct electron configuration for an uncharged selenium atom in the ground state? a. [Ar]3s23d103p4 b. [Ar]4s24d104p4 c. [Ar]4s23d104p4 d. 1s22s22p63s23p64s23d104p6 e. 1s22s22p63s23p64s24d104p6

C

Which of the following elements is misspelled? a. scandium b. vanadium c. tellerium d. iridium e. lanthanum

C

Which of the following sets of isotopic abundance data does NOT make sense based on the atomic weights listed in the periodic table for these elements? a. vanadium-50, 0.25% and vanadium-51, 99.75% b. bromine-79, 50.7% and bromine-81, 49.3% c. lithium-6, 72.3% and lithium-7, 27.7% d. neon-20, 90.5% and neon-22, 9.5% e. boron-10, 19.8% and boron-11, 80.2%

C

A charged atom (-1) has 76 electrons and has a mass number (A) of 190. How many protons and neutrons are in the nucleus of this atom? a. 114 p 190 n b. 115 p 75 n c. 75 p 190 n d. 75 p 115 n e. 76 p 114 n

D

Alkali metals a. react violently with water. b. have one valence electron. c. form 1:1 compounds with halogens. d. all of the above e. none of the above

D

The densities of ethylene glycol, water and wood alcohol are 1.11 g/mL, 1.00 g/mL and 0.79 g/mL respectively. Suppose an object floats in water and ethylene glycol but sinks when placed in wood alcohol. Which of the following could be the density of the object? a. 1.22 g/mL b. 1.11 g/mL c. 1.05 g/mL d. 0.92 g/mL e. 0.75 g/mL

D

The elements tin, titanium, tantalum and thallium are represented respectively by the symbols: a. Ti, Tm, Ta, Th b. Sb, Ti, Tl, Tm c. Sn, Ti, Tl, Th d. Sn, Ti, Ta, Tl e. W, Tc, Tl, Hg

D

The valence electrons in a neutral atom of gallium are: a. 3p1 b. 4p1 c. 3s23p1 d. 4s24p1 e. 4s24p6

D

When a substance undergoes a physical change a. it always undergoes a change of state. b. the process cannot be reversed. c. a new substance is produced. d. its chemical composition remains unchanged. e. heat is always given off.

D

Which of the following is equivalent to 0.002100? a. 2.1 × 103 b. 2.10 × 104 c. 2.10× 10-3 d. 2.100 × 10-3 e. 2.100 × 10-4

D

Which represents the electron configuration of a neutral sodium atom in an excited state? a. [He]2s22p63s13p1 b. 1s22s22p6 c. 1s22s22p53s1 d. [Ne]3p1 e. [Ne]3s2

D

A polonium atom that has gained 2 electrons has the same number of electrons as: a. a neutral atom of lead b. a neutral atom of radium c. an atom of astatine that has lost 1 electron d. an atom of barium that has lost 2 electrons e. an atom of radium that has lost 2 electrons

E

Which of the following would be described as a heterogeneous mixture? a. air, a mixture of O2, N2, CO2 and other gases b. propane gas, C3H8 c. 95% ethyl alcohol (C2H6O dissolved in water) d. elemental sulfur, S8 e. none of the above

E