Chapter 2 Homework - Chemistry

How many protons are in an atom of Fe?

26

Determine the correct formula for aluminum oxide.

A) Al₂O₃

The symbol Cr represents the element _____

D) chromium

The element symbol for copper is _____

E) Cu

What is the mass number for an atom of mercury containing 80 protons and 119 neutrons?

119

What is the atomic number for an element whose mass number is 78, which contains 42 neutrons per atom?

36

Of the following compounds, which contains a metalloid?

A) SiF₄

Write the chemical formula for arsenic pentafluoride

AsF₅

What is the formula for an ionic compound containing Ba²⁺ ions and Cl⁻ ions?

C) BaCl₂

Write the chemical formula for chromium(III) cyanide

Cr(CN)₃

Write the chemical formula for iridum(III) bromide tetrahydrate

IrBr₃•4H₂O

What is the correct IUPAC name for SiCl₄?

Silicon tetrachloride

Which of the following pairs represent isotopes?

C) ²⁸Si and ²⁹Si

Write the chemical formula for carbon tetrafluoride

CF₄

Classify the following compounds as ionic or covalent: KCl, CrCl₃, Cl₂O.

B) Ionic, ionic, covalent.

Which of the following is most likely to make a -3 ion?

B) P

What is the correct IUPAC name for CaBr₂ · 6H₂O?

Calcium bromide hexahydrate

What is the correct IUPAC name for CBr₄?

Carbon tetrabromide

Write the chemical formula for ammonium thiocyanate

NH₄SCN

What is the correct IUPAC name for TiCl₄?

Titanium (IV) chloride

Which of the following would NOT be classified as a molecular element?

E) CO

Cathode rays are composed of what fundamental particle?

D) electrons

When exposed to air, Li metal will react with N₂ in the air to form lithium nitride. What is the charge on the anion in this compound?

E) 3-

Which of the following is most likely to form a +2 ion?

E) Mg

Which is not one of Dalton's hypotheses of atomic theory?

E) The atoms of one element are the same as atoms of another element.

What is the correct IUPAC name for Co(SCN)₂?

Cobalt (II) thiocynate

What is the correct IUPAC name for Co(BrO)₃?

Cobalt (III) hypobromite

What is the correct IUPAC name for CuNO₃?

Copper (I) nitrate

There are three isotopes of an element, X-28, X-29, and X-30, with relative abundances of 92.2297%, 4.6832%, 3.0872%, respectively. a) What is the average atomic mass in amu of this element using four significant figures? b) Which element is this? c) How many neutrons are in an atom of silicon-30?

a) 28.11 amu b) D) Si c) 16

Rutherford's gold foil experiment determined that

C) most of the space in an atom is empty except for a concentrated area called the nucleus.

Toluene is a component of crude oil. It has the chemical formula C₇H₈. What is its empirical formula?

B) C₇H₈

Which of the following statements about subatomic particles are false? I. Some atoms do not have any neutrons. II. Protons and neutrons reside in the nucleus. III. Some atoms do not have any protons.

C) III only

What is the correct IUPAC name for Cr₂(S₂O₃)₃?

Chromium (III) thiosulfate

Write the chemical formula for the chlorite ion

ClO₂⁻

What is the correct IUPAC name for Co(NO₂)₂?

Cobalt (II) nitrite

What is the correct IUPAC name for CuSO₄ · 5H₂O?

Copper (II) sulfate pentahydrate

What is the mass number for an atom of barium containing 56 protons and 81 neutrons?

137

How many carbon atoms are in 27 molecules of benzene, C₆H₆?

162

An unknown element X has the following isotopes: ²⁵X (80.5% abundant) and ²⁷X (19.5% abundant). What is the average atomic mass in amu of X?

25.4 amu

An unknown element is a mixture of isotopes ¹²⁰X and ¹²²X. The average atomic mass of X is 120.70 amu. What is the percent abundance of ¹²²X?

35.0%

The element antimony (Sb) has an atomic mass of 121.76 amu. Two naturally occurring isotopes of antimony are ¹²¹Sb (57% abundant) and ¹²³Sb (43% abundant). In a sample of 100 Sb atoms, what is the probability that a single selected atom has a mass of 121.76 amu?

A) 0%

What is the formula of a compound containing Al³⁺ and S²⁻ ions?

A) Al₂S₃

Which has the correct name-formula combination?

A) Barium oxide - BaO

Which of the following compounds exhibits both ionic and covalent bonding?

A) CaSO₃

A mass spectrometer measures neon to have two masses: 20 and 22 atomic mass units. These are:

A) Isotopes

The element symbol for nickel is _____

A) Ni

An atom has nine protons and ten electrons. This makes it:

A) an ion

What type of forces hold the oxygen atoms together in an O₂ molecule?

A) covalent bonds

Predict the chemical formula for the ionic compound formed by the elements Ag and O

Ag₂O

Write the chemical formula for aluminum perbromate

Al(BrO₄)₃

Predict the chemical formula for the ionic compound formed by Al³⁺ and C₂H₃O₂⁻

Al(C₂H₃O₂)₃

Write the chemical formula for aluminum acetate

Al(C₂H₃O₂)₃

What is the correct IUPAC name for Al₂(CrO₄)₃?

Aluminum chromate

What is the correct IUPAC name for Al(IO₃)₃?

Aluminum iodate

What is the correct IUPAC name for AlPO₄?

Aluminum phosphate

What is the correct IUPAC name for AsBr₃?

Arsenic tribromide

Predict the chemical formula for the ionic compound formed by Au³⁺ and HSO₃⁻

Au(HSO₃)₃

An atom of the isotope ¹³³Cs contains how many protons (p), neutrons (n), and electrons (e)?

B) 55 p, 78 n, 55 e

Determine the number of protons (p) and electrons (e) in N³⁻

B) 7 p, 10 e

Write the chemical formula for tetraphosphorus hexasulfide

P₄S₆

What is the correct IUPAC name for AgI?

Silver iodide

What is the correct IUPAC name for AgNO₂?

Silver nitrite

What is the correct IUPAC name for NaHSO₄?

Sodium hydrogen sulfate

What is the correct IUPAC name for H₂SO₃(aq)?

Sulfurous acid

What is the correct IUPAC name for TiO₂?

Titanium (IV) oxide

What is the correct IUPAC name for V(NO₂)₂?

Vanadium(II) nitrite

Consider two compounds. Compound A contains 15.7 g of sulfur and 18.6 g of fluorine. Compound B contains 25.4 g of sulfur and 60.2 g of fluorine. a) What is the mass ratio of fluorine to sulfur in Compound A? b) What is the mass ratio of fluorine to sulfur in Compound B? c) For Compound A, the ratio of fluorine to sulfur is 1.18. For Compound B, the ratio of fluorine to sulfur is 2.37. Using the Law of Definite Proportions (also called the Law of Constant Composition), could Compound A and Compound B be the same compound?

a) 1.18 b) 2.37 c) D) No, because they have different ratios of the same elements.

In an experiment, the reaction of 100.0 g of iodine produced 144.9 g of a compound formed from iodine and fluorine. a) What mass of fluorine was consumed in the reaction? b) What is the mass ratio of iodine to fluorine in the compound? c) Given that the mass ratio of iodine to fluorine is 2.23, what is the mass in grams of this compound would be expected to form in the same experiment if you started with 85.2 g of iodine?

a) 44.9 g b) 2.23 c) 123.4 g

What is the correct IUPAC name for PBr₃?

Phosphorus tribromide

What is the correct IUPAC name for KClO₃?

Potassium chlorate

Write the chemical formula for the acetate ion

C₂H₃O₂⁻

What is the correct IUPAC name for LiClO₃ · 3H₂O?

Lithium chlorate trihydrate

What is the correct IUPAC name for MgF₂?

Magnesium flouride

What is the correct IUPAC name for Mg₃(PO₄)₂?

Magnesium phosphate

What is the correct IUPAC name for MnCl₃ · 4H₂O?

Manganese(III) chloride tetrahydrate

Write the chemical formula for the dichromate ion

Cr₂O₇²⁻

Write the chemical formula for cesium carbonate

Cs₂CO₃

Write the chemical formula for copper(I) chlorite

CuClO₂

What is the mass number for an atom of zinc containing 30 protons and 39 neutrons?

69

Glucose is an important biological molecule with the molecular formula C₆H₁₂O₆. What is its empirical formula?

B) CH₂O

Which has a greater mass?

B) Proton

What is the atomic symbol for the element in Group 5A (15) and the fifth period?

B) Sb

Which element resides in the third period under group 4A (14) of the periodic table?

B) Si

Which of the following elements would be chemically similar to calcium (Ca)?

B) Sr

Most early attempts to organize the elements were based on atomic mass. Mendeleev occasionally switched elements so that apparently lighter elements occurred after a heavier element. He did this so that elemental properties properly recurred in the same group. This choice anticipated the discovery of which two features of elements?

B) atomic number and isotopes

What type of forces hold the atoms together in a sample of KCl?

B) ionic bonds

The symbol Hg represents the element _____

B) mercury

What is the atomic symbol and mass number for an atom containing 50 protons and 64 neutrons?

B) ¹¹⁴Sn

Write the chemical formula for barium hydroxide octahydrate

Ba(OH)₂•8H₂O

Predict the chemical formula for the ionic compound formed by the elements Ba and S

BaS

What is the correct IUPAC name for BaCr₂O₇?

Barium dichromate

What is the correct IUPAC name for Ba(OH)₂?

Barium hydroxide

Write the chemical formula for the hypobromite ion

BrO⁻

What is the correct IUPAC name for BrCl₃?

Bromine trichloride

Determine the number of protons (p) and electrons (e) in Mg²⁺

C) 12 p, 10 e

Determine the correct formula for chromium(II) nitrite.

C) Cr(NO₂)₂

A molecule has an empirical formula of CH, and its molar mass is known to be 26 g/mol. What is its molecular formula?

C) C₂H₂

The empirical formula of a covalent compound is CH₂. Which of the following is NOT a possible chemical formula for this compound?

C) C₆H₁₀

Determine the correct formula for iron(III) perchlorate.

C) Fe(ClO₄)₃

Which of the following represents a species with 16 protons and 18 electrons?

C) S²⁻

When methane is completely combusted in oxygen forming carbon dioxide and water, how does the mass of the reactant gases compare to the products?

C) The masses of the reactants and products are equal.

What type of forces hold the atoms together in a sample of silver (Ag) metal?

C) metallic bonds

Carbon dioxide is a _____ compound composed two types of _____ atoms.

C) molecular; nonmetal

What is the correct IUPAC name for CsHSO₄?

Cesium hydrogen sulfate

What is the correct IUPAC name for CrBr₃?

Chromium (III) bromide

What is the correct IUPAC name for CrN?

Chromium (III) nitride

Which scientist developed the nuclear model of the atom?

D) Ernest Rutherford

Columns on the periodic table are known as

D) Groups

Classify the following compounds as ionic or covalent: BaO, Fe₂O₃, ZnO.

D) Ionic, Ionic, Ionic.

Which has the correct name-formula combination?

D) Manganese(II) sulfide - MnS

Predict the chemical formula for the ionic compound formed by Fe³⁺ and O²⁻

Fe₂O₃

What is the correct IUPAC name for Au₂O₃?

Gold (III) oxide

Write the chemical formula for hypobromous acid

HBrO

Write the chemical formula for hydrofluoric acid

HF

Write the chemical formula for mercury(I) iodate

Hg₂(IO₃)₂

Write the chemical formula for mercury(I) nitrate dihydrate

Hg₂(NO₃)₂•2H₂O

What is the correct IUPAC name for HCN(aq)?

Hydrocyanic acid

What is the correct IUPAC name for HBrO(aq)?

Hypobromous acid

What is the correct IUPAC name for HOF(aq)?

Hypoflourous acid

Write the formula for sulfurous acid

H₂SO₃

Write the chemical formula for boric acid

H₃BO₃

What is the correct IUPAC name for Fe(IO₄)₂?

Iron (II) periodate

What is the correct IUPAC name for Fe(HSO₄)₃?

Iron (III) hydrogen sulfate

Write the chemical formula for krypton dichloride

KrCl₂

Consider the atom with the chemical symbol Ru. a) What is the name of this element? b) What type of element is Ru? c) What would be the mass number for an atom of Ru which has 56 neutrons? d) What would be the charge on an atom of Ru which only has 41 electrons?

a) D) ruthenium b) B) a transition metal c) 100 d) 3