Exam 3 Pretest

1) The octet rule indicates that A) all of the noble gases have eight total electrons.
B) all of the shells in an atom hold a maximum of 8 electrons.
C) all of the Group A elements have 8 valence electrons.
D) atoms lose, gain, or share valence electrons to have 8 valence electrons.
E) the noble gases react with other compounds to get 8 valence electrons.

2) In ionic compounds, ________ lose their valence electrons to form positively charged ________.

A) metals, anions
B) nonmetals, cations
C) metals, polyatomic ions
D) nonmetals, anions
E) metals, cations

3) How many electrons will aluminum gain or lose when it forms an ion?

A) lose 1
B) gain 5
C) lose 2
D) lose 3
E) gain 1

4) What is the symbol for the ion with 19 protons and 18 electrons?

A) F+
B) F-
C) Ar+
D) K-
E) K+

5) To form an ion, a sodium atom

A) gains one electron.
B) gains two electrons.
C) loses seven electrons.
D) loses one electron.
E) loses two electrons.

An anion always

A) has a positive charge.
B) contains a group of two or more atoms with a positive charge.
C) contains a metal and a nonmetal.
D) forms covalent bonds.
E) has a negative charge.

What is the ionic charge of an ion with 18 protons and 15 electrons?

A) 1+
B) 2+
C) 3+
D) 2-
E) 3-

The number of electrons in an ion with 20 protons and an ionic charge of 2- is

A) 24.
B) 22.
C) 20.
D) 18.
E) 16.

Elements in group 2A(2) of the periodic table form ions with a charge of

A) 1+.
B) 1-.
C) 2+.
D) 3+.
E) 0.

The ion of aluminum is

A) Al+ .
B) Al2+
C) Al3+
D) Al3-
E) Al2-

How many electrons will chlorine gain or lose when it forms an ion?

A) lose 1
B) gain 1
C) lose 7
D) gain 2
E) lose 3

An ionic compound

A) has a net positive charge.
B) has a net negative charge.
C) contains only cations.
D) contains only anions.
E) has a net charge of zero.

The correct formula for a compound formed from the elements Al and O is

A) AlO
B) Al2O
C) Al3O2-
D) AlO3-
E) Al2O3-

The correct formula for the compound formed from Mg and S is

A) MgS
B) MgS2-
C) Mg2S-
D) Mg2S2-
E) Mg2S3-

Which one of the following compounds contains an ion with a 3+ charge?

A) KCl
B) Na2O
C) FeCl3
D) CuCl
E) MgCl2

16) What is the correct formula for the oxide ion?

A) O2-
B) O
C) O+
D) O2+
E) O3+

17) The compound MgCl2 is named

A) magnesium chlorine.
B) magnesium dichloride.
C) magnesium (II) chloride.
D) magnesium chloride.
E) dimagnesium chloride.

) Which one of the following elements forms two or more ions with different ionic charges?

A) K
B) F
C) Ca
D) O
E) Fe

19) What is the correct formula for the iron (II) ion?

A) Fe+
B) Fe2+
C) Fe3+
D) Fe2-
E) Fe3-

) The name of the Cu+ ion is

A) copper (II).
B) copper (I).
C) copper (III).
D) copper.
E) cuprum.

What is the correct formula for iron (III) sulfide?

A) Fe2S2
B) Fe2S
C) FeS
D) FeS2
E) Fe2S3

A(n) ________ is the smallest neutral unit of two or more atoms held together by a covalent bond.

A) ionic compound
B) nucleus
C) molecule
D) formula
E) unit

In a molecule with covalent bonding,

A) oppositely charged ions are held together by strong electrical attractions.
B) atoms of metals form bonds to atoms of nonmetals.
C) atoms of different metals form bonds.
D) atoms are held together by sharing electrons.
E) atoms of noble gases are held together by attractions between oppositely charged ions.

Which of the following elements does NOT exist as a diatomic molecule?

A) hydrogen
B) nitrogen
C) chlorine
D) oxygen
E) carbon

In a covalently bonded molecule, the number of electrons that an atom shares with others is usually equal to the number of electrons

A) in the atom.
B) in its nucleus.
C) in all the atoms.
D) in its ion.
E) needed to give it a noble gas arrangement.

Double and triple bonds form because

A) the atoms involved have high electronegativities.
B) single covalent bonds do not give all of the atoms in the molecule eight valence electrons.
C) one of the atoms in the molecule has more than 8 valence electrons.
D) the ions involved have charges larger than one.
E) there is at least one hydrogen atom involved in the bond.

The correct name of the compound NCl3 is

A) nitrogen chloride.
B) trinitrogen chloride
C) nitrogen(III) chloride.
D) nickel chloride.
E) nitrogen trichloride.

According to naming rules, the types of compound that use prefixes in their names are

A) ionic compounds.
B) ionic compounds involving transition metals.
C) polyatomic ions.
D) covalent compounds.
E) compounds that contain polyatomic ions.

The correct name for the compound N2O3 is

A) nitrogen oxide.
B) nitrogen trioxide.
C) dinitride trioxide.
D) dinitrogen oxide.
E) dinitrogen trioxide.

What is the formula of carbon tetraiodide?

A) CI
B) CI4
C) C4I
D) CI3
E) C2I4

The name of Al2(SO4)3 is

A) aluminum(III) sulfate.
B) dialuminum trisulfate.
C) dialuminum sulfate.
D) dialuminum trisulfide.
E) aluminum sulfate.

The ability of an atom to attract the shared electrons in a covalent bond is its

A) electronegativity.
B) bonding ability.
C) polarity.
D) ionic character.
E) nonpolarity.

Which of the following substances contains a nonpolar covalent bond?

A) H2O
B) NaCl
C) NH3
D) MgF2
E) N2

Which of the following compounds contains a polar covalent bond?

A) NaF
B) HCl
C) Br2
D) MgO
E) O2

Which of the following compounds contains an ionic bond?

A) NH3
B) H2O
C) CaO
D) H2
E) Ch4

One mole of particles of any substance contains how many particles?

A) 10^6
B) 3 x 10^-10
C) 3 x 10^10
D) 6.02 x10^23
E) 6.02 x 10^-23

Avogadro’s number is the number of

A) particles in 1 mole of a substance.
B) amu in 1 mole of a substance.
C) grams in 1 mole of a substance.
D) moles in 6.02 x 10^23 grams of an element.
E) moles in 6.02 x 10^23 amu of an element.

One mole of copper(II) sulfate, CuSO4, contains________ O atoms.

A) 4
B) 6.02 x 10^23
C) 1.51 x 10^22
D) 2.41 x 10^23
E) 2.41 x 10^24

0.400 mole of sucrose, C12H22O11 contains ______ C atoms

A) 12
B) 6.02 x 10^23
C) 5.02 x 10^22
D) 2.89 x 10^24
E) 4.80

1 mole of neon has a mass of
A) 6.02 x 10^23 g
B) 14.0g
C) 10.0g
D)20.2 g
E) 30.2g

the molar mass of C3H8O2 is
A) 76.0g
B) 60.0g
C)29.0g
D)69.0g
E)52.03g

the molar mass of Calcuim Hydroxide, Ca(OH)2, is

A)58.1g
B)57.1g
C)74.1g
D)14.2g
E)38.0g

What is the molar mass of Mg3(PO4)2, a substance formerly used in medicine as an antacid?

A) 71.3 g
B) 118.3 g
C) 150.3 g
D) 214.3 g
E) 262.9 g

How many moles of water, H2O, are present in 75.0 g H2O?

A) 4.41 moles
B) 4.17 moles
C) 75.0 moles
D) 7.50 moles
E) 1.35 x 10^3 moles

How many grams of glucose (C6H12O6) are in 3.55 moles of glucose?

A) 180 g
B) 639 g
C) 103 g
D) 426 g
E) 50.7 g

A chemical equation is balanced when

A) the total number of molecules is the same in reactants and products.
B) the total number of ions is the same in reactants and products.
C) the sum of the coefficients of the reactants is equal to the sum of the coefficients of the products.
D) the number of atoms of each element is the same in reactants and products.
E) the charge on each atom is the same in reactants and products.

Which of the following gives the balanced equation for this reaction?

K3PO4+Ca(NO3)2 —> Ca3(PO4)2 + KNO3

A) KPO4 + CaNO3 + KNO3
B) K3PO4 + Ca(NO3)2 –> Ca3(PO4)2 + 3KNO3
C) 2K3PO4 + Ca(NO3)2 –> Ca3(PO4)2 + 6KNO 3
D) 2KPO4 + 3Ca(NO3)2 –> Ca3(PO4)2 + 6KNO3
E) K3PO4 + Ca(NO3)2 –> Ca3(PO4)2 + KNO3

Which of the following correctly gives the best coefficients for the reaction below?

N2H4 + H2O2 –> N2 + H2O

A) 1, 1, 1, 1
B) 1, 2, 1, 4
C) 2, 4, 2, 8
D) 1, 4, 1, 4
E) 2, 4, 2, 4

What coefficient is placed in front of to complete the balancing of the following equation?

C5H8 + ?O2 –> 5CO2 + 4H2O

A) 1
B) 3
C) 5
D) 7
E) 9

(H2O) according to the following reaction. Answer the following question(s) about this reaction.
C5H12 + ?O2 –> ?CO2 + ?H2O

What is the coefficient for oxygen in the balanced equation?
A) 2
B) 4
C) 5
D) 6
E) 8
What is the coefficient for carbon dioxide in the balanced equation?
A) 2
B) 4
C) 5
D) 6
E) 8