Chem exam 2

Consider the reaction shown and identify the statement that is not true. CaCO3 (s) → CaO (s) + CO2 (g) a. water is needed for the reaction to proceed b. the equation is balanced c. the products are a solid and a gas d. there are no solutions in this reaction

a

The charge on a sulfide ion is _________. a. 2- b. 6+ c. 4+ d. 2+

a

The net ionic equation for the reaction between zinc and hydrochloric acid solution is ______________. a.Zn(s) + 2 H+(aq) → Zn2+(aq) + H2(g) b. Zn2+(aq) + H2(g) → ZnS(s) + 2 H+(aq) c. ZnCl2(aq) + H2(g) → ZnS(s) + 2 HCl(aq) d.Zn(s) + 2 HCl(aq) → ZnCl2(aq) + H2(g) e. none of the above

a

The smallest possible unit of a covalent compound is a(an) ___________. a. molecule b. ion c. polyatomic d. electron

a

The spectator ions in the following reaction are 2 AgNO3(aq) + K2SO4(aq) → 2 KNO3(aq) + Ag2SO4(s) a. potassium ion and nitrate ion b. silver ion and sulfate ion c. silver ion and nitrate ion d. potassium ion and sulfate ion e. hydrogen ion and hydroxide ion

a

What is the name of Mg3(PO4)2? a. magnesium phosphate b. magnesium phosphide c. trimagnesium phosphorous d. magnesium phosphorous oxide

a

When the following reaction is balanced, the coefficient in front of carbon dioxide is:___ C5H12 + ___ O2 → ___ CO2 + ___ H2O a. 5 b. 11 c. 6 d. 10 e. 12

a

Which element listed is the most electronegative? a. Cl b. C c. Na d. B

a

Which is the correct equation for the reaction between magnesium with hydrochloric acid to produce hydrogen and magnesium chloride? a. Mg + 2 HCl → H2 + MgCl2 b. Mg + HCl → H + MgCl c. 2 Mg + 6 HCl → 3 H2 + 2 MgCl2 d.Mg + 2 HCl → 2 H + MgCl2 e. Mg + 3 HCl → 3 H + MgCl2

a

Which property could describe a covalent compound? a. it is a gas at room temp b. it conducts electricity c. its a brittle solid d. its composed of a metal and a non-metal

a

What is the name of AlCl3? a. trialuminum chloride b.aluminum chloride c.aluminum carbide d.aluminum (III) chloride e.aluminum trichloride

b

What is the name of Mn3As7? a. trimanganese arsenide b. manganese(VII) arsenide c. heptamanganese arsenide d. magnesium arsenic

b

When a substance loses an electron, it is acting as an __________. a. oxidizing agent b. reducing agent c. neither

b

Which group contains only elements that normally exist as diatomic molecules? a. nitrogen; sulfur; bromine b. nitrogen; oxygen; fluorine c. hydrogen; lithium; sodium d. helium; neon; argon e. oxygen; phosphorous; germanium

b

Which of the compounds is most likely ionic? a. nitrogen dioxide b. strontium bromide c. carbon monoxide d. carbon tetrachloride

b

Which of the following could represent a compound that is classified as a base? a. calcium sulfate b. magnesium hydroxide c. hydrogen gas d. all of the above

b

Which of the following ions does not have the same electron configuration as the noble gas neon? a.Mg+2 b.S-2 c. F- d. Al+3 e. O-2

b

Which of the following is not soluble in water? a. iron(III) nitrate b. iron(III) hydroxide c. ammonium sulfate d. potassium sulfide e. iron(II) bromide

b

In the correctly balanced reaction, the coefficient for H2O is:___ Al(OH)3 + ___ H2SO4 → ___ Al2(SO4)3 + ___ H2O a. 2 b. 3 c. 6 d. 1 e. 8

c

What is the charge of an ion that will be formed from an element that has seven valence electrons? a electronegativity b. electron affinity c. ionization energy d. atomic number e. none of the above

c

When looking at a bond between nitrogen and oxygen, which of the following is true? a. both atoms have a partial negative charge b. the nitrogen has a partial negative charge; the oxygen has a partial positive charge c. the nitrogen has a partial positive charge; oxygen has a partial negative charge d. the electrons are shared equally

c

When the reaction shown is correctly balanced, the coefficients are:___ KClO3 → ___ KCl + ___ O2 a. 2,2,2 b. 4,4,6 c.2,2,3 d.1,1,1 e. 2,2,1

c

A precipitation reaction typically has two reactants and two products. What state will the products be in? a. aqueous and liquid b. liquid and liquid c. solid and solid d. solid and aqueous solution

d

Although noble gases do not normally form covalent compounds, XeO3 has been prepared. The name of this compound is __________. a. xenon (III) oxide b. trixenon trioxide c. trioxy xenon d. xenon trioxide e. none of the above

d

In a Lewis dot structure, the electrons which complete an octet but are not located between two atoms are referred to as ___________. a. extra electrons b. filled shells c. double bonds d. lone pairs

d

In a chemical reaction, _________________. a. there are always the same number of products as there are reactants b. the numbers of atoms present in a reaction can vary when conditions change during the reaction c. there are equal numbers of molecules on each side of the reaction arrow d. there are equal numbers of atoms on each side of the reaction arrow

d

In a precipitation reaction, the insoluble product can be identified by the symbol ________. a. aq b. g c. l d. s

d

One definition of an acid is a substance that provides what ion in water? a. Na+ b. NH4+ c. OH- d. H+

d

The oxidation number of iron in the compound FeBr3 is ________. a. +2 b. +4 c. +1 d.+3

d

The water molecule has a ________geometry because its central atom has ________ bonds and ________ lone pairs of electrons. a. pyramidal; two; one b. tetrahedral; four; none c. linear; two; two d. bent; two; two

d

What is the charge of an ion that will be formed from an element that has seven valence electrons? a. 1+ b. 3+ c. 5- d. 1-

d

What is the formula for the compound formed between calcium and sulfur? a. CaSi b. SCa c. CaSu d. CaS

d

What is the symbol for an ion that has 19 protons and 18 electrons? a. Ar+1 b. Na+1 c. Ca+1 d. K+1 e. Sr+1

d

When a solution of iron(III) nitrate is mixed with a solution of sodium hydroxide, a rust-colored precipitate forms. This precipitate is probably __________. a. iron(III) oxide b. sodium hydride c. sodium nitrate d. iron(III) hydroxide e. all of the above

d

Which element is most likely to form three covalent bonds? a. O b. Cl c. C d. P

d

Which is the correct formula for the ionic compound containing iron (III) ions and oxide ions? a. FeIIIO b. Fe3O2 c. FeO d. Fe2O3 e. None of the above

d

Which statement regarding balanced chemical equations is not true? a. reactants are written to the left of the reaction arrow b. when no coefficient is written in front of the formula, the number "one" is assumed c. coefficients are used in front of formulas to balance equations d. subscripts may be changed to make an equation simpler to balance e. the number of each kind of atom must be the same on each side

d

The number of valence electrons in the acetic acid molecule, CH3CO2H, is a. 0 b. 16 c. 32 d. 8 e.24

e

Which representation of a methane molecule is not correct? (A methane molecule is composed of one carbon atom and four hydrogen atoms.) a. CH4 b. (look at structure) c. (look at structure) d. all shown are correct e. none of the above

e

A chemical bond formed when two atoms share two pairs of electrons is a ________ bond; it is best described as________. a. single; covalent b. double; covalent c. single; ionic d. triple; ionic

b

In order to form an octet, an atom of selenium will __________. a. lose 2 electrons b. gain 2 electrons c. gain 6 electrons d. gain 3 electrons e. lose 6 electrons

b

In order to form the salt calcium sulfate, which acid and base combination should you choose? a. H2SO3 and Ca(OH)2 b. H2SO4 and Ca(OH)2 c. H2SO4 and CaOH d.H2SO3 and CaOH e. None of the above

b

Main group elements that are metals usually ______ one or more electrons to form _______, which have a _______ charge. a. lose; anions; negative b. lose; cations; positive c. gain; cations; positive d. gain; anions; negative

b

The balanced equation for the reaction occurring when iron(III) oxide, a solid, is reduced with pure carbon to produce carbon dioxide and molten iron is ____________. a.4 Fe2O3(s) + 6 C(s) → 8 Fe(l) + 6 CO2(g) b.2 Fe2O3(s) + 3 C(s) → 4 Fe(l) + 3 CO2(g) c.2 FeO(s) + C(s) → 2 Fe(l) + CO2(g) d.2 Fe3O(s) + C(s) → 6 Fe(l) + CO2(g) e.2 FeO3(s) + 3 C(s) → 2 Fe(l) + 3 CO2(g)

b

The element chlorine is very reactive as a(an) ________ agent because it readily ________ electrons to form the chloride ion. a. oxidizing; loses b. oxidizing; gains c. reducing; gains d. reducing; loses

b

The formula PO4-3 means that an ion is composed of __________. a. four atoms of phosphorous, four atoms of oxygen, and three electrons have been lost b. one atom of phosphorous, four atoms of oxygen, and three extra electrons c. one atom of phosphorous, one atom of oxygen, and three extra electrons d. four atoms of phosphorous, four atoms of oxygen, and three extra electrons e.one atom of phosphorous, four atoms of oxygen, and three electrons have been lost

b

The formula for phosphorous pentafluoride is ________. a.PhF5 b.PF5 c.P5F d.(PF)5 e. P5F5

b

What is the formula of the ammonium ion? a. AmO b. NH4+ c. NH4-1 d. Am+

b