Chemistry 1411

Practice questions for Exam 2(chapter 3)

1) How many electrons are in the ion, P3-?

A) 12

B) 18

C) 28

D) 34

2) What is the identity of element Q if the ion Q2+ contains 10 electrons?

A) C

B) O

C) Ne

D) Mg

3) How many electrons are in the ion, CO32-?

A) 16

B) 28

C) 30

D) 32

4) Which of the following is the correct chemical formula for a molecule of bromine?

A) Br

B) Br-

C) Br+

D) Br2

5) Which of the compounds, C3H8, MgCl2, Zn(NO3)2, OCl2, are expected to exist as

molecules?

A) only C3H8

B) C3H8 and OCl2

C) C3H8, Zn(NO3)2, and OCl2

D) MgCl2 and Zn(NO3)2

6) How many electrons are in the outermost shell of the In3+ ion in its ground state?

A) 2

B) 3

C) 6

D) 18

7) Which ion has the smallest ionic radius?

A) F–

B) Cl–

C) Br–

D) I–

8) Which ionization process requires the most energy?

A) P(g) → P+(g) + e-

B) P+(g) → P2+(g) + e-

C) P2+(g) → P3+(g) + e-

D) P3+(g) → P4+(g) + e-

9) Calculate the energy change for the formation of CaF2(s) from its elements in their

standard states and the following information:

A) +4046 kJ/mol

B) -965 kJ/mol

C) -1214 kJ/mol

D) -3286 kJ/mol

10) What is the charge on the Cr in the ionic compound Cr2O3?

A) 2-

B) 1+

C) 2+

D) 3+

11) The chemical formula for calcium nitride is

A) Ca(NO3)2.

B) Ca(NO2)2.

C) Ca3N2.

D) CaN2.

12) The bonding in MgO is ________, whereas the bonding in CO is ________.

13) Which of the species below has 28 protons and 26 electrons?

A) Fe2+

B) Ni2+

C) 54Fe

26

D) 54N i

28

14) How many electrons are in the ion, Zn2+?

A) 28

B) 30

C) 32

D) 65

15) The solid compound, Na2CO3, contains

A) Na+, C4+, and O2- ions.

B) Na+ ions and CO32- ions.

C) Na2+ and CO32- ions.

D) Na2CO3 molecules.

16) Which one of the following compounds contains ionic bonds?

A) CaO

B) HF

C) NI3

D) SiO2

17) What is the ground-state electron configuration of Se2-?

A) [Ar]3d104s24p2

B) [Ar]3d104s24p4

C) [Ar]3d124s24p4

D) [Ar]3d104s24p6

18) Which element has the most favorable (most negative) electron affinity?

A) B

B) C

C) Li

D) N

19) What is the general trend in ionization energy and electron affinity values?

A) Both decrease as one traverses a period from left to right and both decrease as one

descends a group.

B) Both decrease as one traverses a period from left to right and both increase as one

descends a group.

C) Both increase as one traverses a period from left to right and both decrease as one

descends a group.

D) Both increase as one traverses a period from left to right and both increase as one

descends a group.

20) Which of the following elements has the least tendency to form an ion?

A) Ca

B) K

C) Kr

D) Se

21) An element that has the valence electron configuration 3s23p3 belongs to which

period and group?

A) period 3; group 3A

B) period 3; group 5A

C) period 4; group 3A

D) period 4; group 5A

22) An element M reacts with chlorine to form MCl2, with oxygen to form MO, and with

nitrogen to form M3N2. The most likely candidate for the element is

A) Li

B) Mg

C) Al

D) Si

23) Calculate the lattice energy for MgCl2(s) using a Born-Haber cycle and the following

information:

A) +641.6 kJ/mol

B) +1240.5 kJ/mol

C) +1882.1 kJ/mol

D) +2523.7 kJ/mol

24) Calculate the energy change for the formation of MgBr2(s) from its elements in their

standard states:

A) -150.8 kJ/mol

B) -286.0 kJ/mol

C) -499.2 kJ/mol

D) -5682 kJ/mol