Question 1

Which of the following correctly ranks the ionic compounds CaO, NaBr, and MgO from smallest to largest lattice energy magnitude?

Accepted Answer

NaBr \u003c CaO \u003c MgO

Question 2

How many resonance structures can be drawn for XeO$$_4 in $$which the central atom has a formal charge of 0 and all terminal atoms have formal charges of zero?

Accepted Answer

$$4$$

Question 3

An impure sample of hydrocarbon with a mass of $$35.0\ \mathrm{g}$$ undergoes combustion to produce $$54.6\ \mathrm{g} CO$_2$$ and $$17.3\ \mathrm{g} H$_2O. $$What percentage of the initial sample is pure hydrocarbon?

Accepted Answer

$$71.1\%$$

Question 4

Which molecular orbital could be formed by the in-phase overlap of the adjacent atomic orbitals shown below (head-to-head overlap of p orbitals)?

Accepted Answer

$$\sigma_{2p}$$

Question 5

Which of the following ions is isoelectronic with K$$^+$$?

Accepted Answer

Cl$$^-$$

Question 6

Consider the proposed Lewis structure for SF$$_4$$ shown below. Which of the following mistakes/issues does the Lewis structure exhibit?

$$\begin{array}{c}
\mathrm{F} - \mathrm{S} - \mathrm{F} \
| \quad \quad | \
\mathrm{F} \quad \quad \mathrm{F}
\end{array}$$

Accepted Answer

The structure shows the wrong number of electrons in total and places positive formal charges on highly electronegative fluorine atoms.

Question 7

What mass of aluminum oxide is required to provide the same number of oxide ions as in $$186\ \mathrm{g} of $$lead(IV) oxide ($$\mathrm{PbO}_2$$)?

Accepted Answer

$$70.6\ \mathrm{g}$$

Question 8

The bond energy of Br–Br is $$193\ \mathrm{kJ/mol}. $$Which one of the following chemical equations is associated with this value?

Accepted Answer

$$\mathrm{Br}_2(g) \rightarrow 2\ \mathrm{Br}(g)$$

Question 9

A molecule of compound X contains $$13$$ carbon atoms (along with other non-carbon atoms) and is $$75.6\%$$ carbon by mass. What is the molar mass of compound X?

Accepted Answer

$$206.3\ \mathrm{g/mol}$$

Question 10

The neutral atom having which electron configuration below is expected to have the largest second ionization energy?

Accepted Answer

$$[\mathrm{Ne}]\ 3s^1$

Question 11

Based on Molecular Orbital (MO) theory, which of the following is predicted to have the most unpaired electrons in its ground state MO diagram?

Accepted Answer

$$\mathrm{O}_2$$

Question 12

Rank the following atoms in order of decreasing electronegativity: F, Cs, Mg, P.

Accepted Answer

F \u003e P \u003e Mg \u003e Cs

Question 13

Which of the following compounds contains bonds with the greatest percent ionic character?

Accepted Answer

HF

Question 14

Molecules of which of the following organic families necessarily contains nitrogen?

Accepted Answer

Amines

Question 15

Draw the best contributing resonance structure for HNO$$_2$$ and choose a true statement about this structure.

Accepted Answer

There is a single bond between N and O.

Question 16

Calculate the mass of chlorine in $$250.0\ \mathrm{g} of C$_2F$_3Cl$_3.$$

Accepted Answer

$$142\ \mathrm{g}$$

Question 17

A student draws a Lewis structure for HNO$$_2$$ having 24 electrons and in which the formal charge on each atom is zero. Select a true statement about this structure.

Accepted Answer

The structure is invalid because it expends the octet of N.

Question 18

All of the following compounds are molecular except:

Accepted Answer

NH$$_4Cl$$

Question 19

How many of the following molecules could be either polar or nonpolar depending on how the atoms are arranged around the central atom? (CO$$_2$$, PF$$_5$$, XeF$$_4$$, SF$$_4)$$

Accepted Answer

$$2$$

Question 20

Element M is a metal that forms an ionic compound with the formula M$$_2(NO$_3$$)$$_2$$ and a molar mass of $$213.0\ \mathrm{g/mol}. $$What is the molar mass of the ionic compound that forms between M and oxygen?

Accepted Answer

$$120.0\ \mathrm{g/mol}$$

Question 21

The structure of caffeine is shown below. Determine the number of sigma bonds and pi bonds in caffeine.

Accepted Answer

$$21\ \sigma-$$bonds,\ 4\ \pi$-bonds

Question 22

What is the hybridization and molecular geometry about the carbon atom in a carboxylic acid functional group?

Accepted Answer

sp$$^2$$, trigonal planar

General Chemistry Exam Review: Atomic Structure, Bonding, Molecular Geometry, and Chemical Properties

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