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
