Question 1

Which of the following best explains why the first ionization energy generally increases across a period from left to right in the periodic table?

Accepted Answer

The effective nuclear charge increases, pulling electrons closer to the nucleus.

Question 2

Which of the following ions has the smallest radius?

Accepted Answer

$$\mathrm{Mg$$^{2+}$$}$$

Question 3

Which of the following elements has the highest electron affinity?

Accepted Answer

Fluorine ($$\mathrm{F})$$

Question 4

Which of the following molecules violates the octet rule?

Accepted Answer

$$\mathrm{BF_3$}$$

Question 5

Which of the following best describes the bonding in $$\mathrm{NaCl}$$?

Accepted Answer

Ionic bonding with electron transfer from Na to Cl

Question 6

Which of the following molecules is polar?

Accepted Answer

$$\mathrm{H_2O}$$

Question 7

What is the molecular geometry of $$\mathrm{NH_3$}$$ according to the VSEPR model?

Accepted Answer

Trigonal pyramidal

Question 8

Which of the following statements about resonance structures is correct?

Accepted Answer

The actual structure is a hybrid of all resonance forms.

Question 9

Which of the following bonds is the shortest and strongest?

Accepted Answer

Triple bond in $$\mathrm{N_2$}$$

Question 10

Which hybridization corresponds to the central atom in $$\mathrm{CH_4$}$$?

Accepted Answer

$$sp^3$$

Question 11

A sample of gas occupies $$2.0\ \mathrm{L} at$$ $$1.0\ \mathrm{atm}$$ and $$300\ \mathrm{K}. $$What will be its volume at $$2.0\ \mathrm{atm}$$ and $$300\ \mathrm{K}$$?

Accepted Answer

$$1.0\ \mathrm{L}$$

Question 12

Which of the following gases will effuse the fastest under identical conditions?

Accepted Answer

$$\mathrm{H_2$}$$

Question 13

Which of the following best describes the kinetic-molecular theory of gases?

Accepted Answer

Gas particles are in constant, random motion and have negligible volume.

Question 14

Which of the following molecules has a bond angle closest to $$109.5^\circ$$?

Accepted Answer

$$\mathrm{NH_3$}$$

Question 15

A mixture contains $$2.0\ \mathrm{mol} of$$ $$\mathrm{N_2$}$$ and $$3.0\ \mathrm{mol} of$$ $$\mathrm{O_2$} in a$$ $$10.0\ \mathrm{L}$$ container at $$300\ \mathrm{K}. $$What is the total pressure? $$(R = 0.0821\ \mathrm{L\ atm\ $$mol^{-1}$$\ K$$^{-1}$$})$$

Accepted Answer

$$12.3\ \mathrm{atm}$$

Question 16

Which of the following best explains why $$\mathrm{F_2$} is a $$nonpolar molecule even though the $$\mathrm{F-F}$$ bond is polar?

Accepted Answer

The molecule is linear and the bond dipoles cancel.

Question 17

Which of the following is the correct Lewis structure for $$\mathrm{CO_2$}$$?

Accepted Answer

O=C=O, with each O atom having two lone pairs

Question 18

Which of the following statements about electronegativity is correct?

Accepted Answer

Electronegativity increases across a period and decreases down a group.

Question 19

Which of the following best describes the orbital overlap in a sigma ($$\sigma) $$bond?

Accepted Answer

End-to-end overlap of orbitals along the internuclear axis

Question 20

A real-world application: In the Haber process for ammonia synthesis, $$\mathrm{N_2$}$$ and $$\mathrm{H_2$}$$ react to form $$\mathrm{NH_3$}. $$Which property of $$\mathrm{N_2$}$$ makes this reaction require high temperature and pressure?

Accepted Answer

$$\mathrm{N_2$}$$ has a very strong triple bond.

General Chemistry Study Guide: Periodic Properties, Chemical Bonding, Molecular Geometry, and Gases

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