Chapter 1 Flashcards
The atomic number of boron is 5. The correct electronic configuration of boron is: A) 1s22s3 B) 1s22p3 C) 1s22s22p1 D) 2s22p3 E) 1s22s23s1
C) 1s22s22p1
How many distinct p orbitals exist in the second electron shell, where n = 2? A) 2 B) 3 C) 4 D) 5 E) 6
B) 3
The \_\_\_\_\_\_\_\_ tells us that each orbital can hold a maximum of 2 electrons. A) aufbau principle B) Pauli exclusion principle C) Hund's rule principle D) LeChatelier principle E) uncertainty principle
B) Pauli exclusion principle
A node is a region of high electron density between the two atoms in a covalent bond.
true or false?
Answer: FALSE
When filling two or more orbitals of the same energy with electrons, the electrons will go into different orbitals rather than pair up in the same orbital.
true or false?
Answer: TRUE
Atoms with the same number of protons but different numbers of neutrons are called ________.
Answer: isotopes
The electron density of ________ orbitals has spherical symmetry.
s
An oxygen atom has ________ valence electrons.
6
Orbitals which are equal in energy are referred to as \_\_\_\_\_\_\_\_. A) degenerate B) polar C) nodes D) filled E) nonpolar
A) degenerate
In a carbon atom, the 2s and 2p orbitals are equal in energy.
true or false?
Answer: FALSE
A carbon-hydrogen bond in ethane (CH3CH3) is best described a \_\_\_\_\_\_\_\_. A) highly polar B) essentially nonpolar C) ionic D) a multiple bond E) resonance stabilized
B) essentially nonpolar
The electronegativity of elements on the periodic table increases going \_\_\_\_\_\_\_\_ a column and to the \_\_\_\_\_\_\_\_ in each row. A) up, right B) up, left C) down, right D) down, left
A) up, right
Which of the following molecules contains a polar covalent bond? A) H2 B) F2 C) CH3Cl D) NaCl E) He
C) CH3Cl
The compound methylamine, CH3NH2, contains a C-N bond. In this bond, which of the following best describes the charge on the carbon atom? A) +1 B) slightly positive C) uncharged D) slightly negative E) -1
B) slightly positive
The formal charge on oxygen in dimethyl ether, CH3OCH3, is \_\_\_\_\_\_\_\_. A) +2 B) +1 C) 0 D) -1 E) -2
C) 0
For most compounds in which a nitrogen atom bears no formal charge, the valence of this nitrogen atom is ________.
Answer: 3
In the compound sodium methoxide (NaOCH3), there is \_\_\_\_\_\_\_\_ bonding. A) ionic B) polar covalent C) nonpolar covalent D) a mixture of ionic and covalent E) resonance stabilized
D) a mixture of ionic and covalent
Which of the following compounds are covalent compounds? A) KCl B) CF4 C) NH3 D) both A and B E) both B and C
E) both B and C
When a negatively charged species is most appropriately depicted as a hybrid of several resonance forms, the negative charge present is considered to be rapidly moving between the resonance forms bearing the formal negative charge.
true or false?
Answer: FALSE
When a molecule can best be represented as a series of resonance forms, each of these forms always contributes to the same degree in the hybrid.
true or false?
Answer: FALSE
A sample of compound X is subjected to elemental analysis and the following percentages by weight are found: 39.97% C, 6.73% H, and 53.30% O. The molecular weight of X is 90. What is the empirical formula of X? A) C6HO8 B) C2H4O2 C) C4H10O2 D) C3H6O3 E) CH2O
E) CH2O
Calculate the molecular formula for the organic compound whose quantitative elemental analysis showed 48.6% caron and 8.1% hydrogen by weight. A) CH2O B) C2H4O2 C) C2H6 D) C3H6O E) C3H6O2
E) C3H6O2
The pH of a 150 mL aqueous solution of 2.13 x 10-3 M HCl is \_\_\_\_\_\_\_\_. A) -3.000 B) 3.000 C) 2.672 D) 2.130 E) none of the above
C) 2.672
What is the pKa and general acid strength of formic acid if its conjugate base form has a pKb of 10.23?
A) 3.77 - fairly strong weak acid
B) 5.99 - moderately strong weak acid
C) 14.00 - not an acid but rather a strong base
D) 3.23 - fairly strong weak acid
E) cannot be determined from the information given
A) 3.77 - fairly strong weak acid
The conjugate acid of ammonia, NH3, is \_\_\_\_\_\_\_\_. A) NH2- B) NH2OH C) NH4+ D) none of the above
C) NH4+
The Ka of formic acid is 1.7 x 10-4. The pKa of formic acid is \_\_\_\_\_\_\_\_. A) 1.70 B) 4.00 C) -2.36 D) 3.77 E) 10.38
D) 3.77
When methanol (CH3OH) acts as a base, its conjugate acid is \_\_\_\_\_\_\_\_. A) -CH2OH B) CH3O- C) CH4OH D) CH3OH2+ E) CH4O+
D) CH3OH2+
Which of the following pairs of bases lists the stronger base first? A) I- > Cl- B) H2O > HO- C) HO- > H2N- D) CH3COO- > HO- E) H2N- > CH3COO-
E) H2N- > CH3COO-
According to the following pKa values listed for a set of acids, which would lead to the strongest conjugate base? A) -2 B) 1 C) 7 D) 25 E) 50
E) 50
Rank the following compounds in order of increasing acidity: CH3OH, HCl, NH3, and CH4.
Answer: CH4
Rank the following compounds in order of increasing basicity: CH3O-, H2N-, H2O, and NH3.
Answer: H2O
Which of the following acids has the most stable conjugate base? A) CH3CO2H B) CH3CHO C) CH3CH2OH D) CH3CH2SH E) CH3SO3H
E) CH3SO3H
The hydroxide ion (HO-) cannot function well as which of the following? A) a Bronsted-Lowry base B) a Lewis base C) a nucleophile D) an electron-pair acceptor E) a proton acceptor
D) an electron-pair acceptor
Which of the following terms comes closest to describing an electrophile? A) anion B) Lewis base C) Lewis acid D) nucleophile E) nonpolar
C) Lewis acid
According to the Lewis definition, which of the following may act as acids? A) NH3 B) HCl C) AlCl3 D) A & B E) A, B, & C
E) A, B, & C
Consider the species CH3O-, NH2-, and CH3COO-. Rank these ions in order of increasing basicity.
Answer: CH3COO-
