Chem 25 Chapter 2-3

What is the mass number for an atom of barium containing 56 protons and 80 neutrons?

136

Solid sodium reacts with liquid water to form hydrogen gas according to the equation 2 Na(s) + 2 H₂O(l) → 2 NaOH(aq) + H₂(g) What is the pressure (in atm) of hydrogen gas in the 20.0 L headspace of a reactor vessel when 2.60 kg sodium is reacted with excess water at 50.0°C?

74.9 atm Explanation: 2.60 kg Na (1000 g/1kg)(1 mol Na/22.99 g)(1 mol H2/2 mol Na)=56.546 mol H2 pV=nRT p=nRT/V p=(56.546 mol H2)(0.08206 L atm/mol K)(50+273.15)/20 L=74.9 atm

What is the formula of a compound containing Al³⁺ and S²⁻ ions? A) Al₂S₃ B) Al₂S C) AlS₃ D) Al₃S₂

A) Al₂S₃ Explanation: Two aluminum ions are needed to balance out the negative charge on the three sulfur ions. This is the lowest number of each ion to reach a neutral formula unit.

Which of the following sets of elements and symbols is paired correctly? A) neodymium, Nd B) cerium, Cr C) osmium, O D) krypton, K E) radon, Ra

A) neodymium, Nd Explanation: The Periodic Table provides element names and symbols. Neodymium has the symbol "Nd."

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

Ag₂O

How many neutrons are in an atom of uranium-235? A) 92 B) 143 C) 235 D) 238.0

B) 143 Explanation: Uranium-235 has a mass of 235. Uranium always has 92 protons. Therefore, uranium-235 has 143 neutrons.

How many neutrons are in a ⁴He atom? A) 0 B) 2 C) 4 D) 6

B) 2 Explanation: The mass number, 4, is the number of protons plus neutrons. Because helium always has 2 protons, this atom has 2 neutrons.

The element symbol for arsenic is _____ A) Ar B) As C) Ac D) Ae E) Ai

B) As Explanation: The Periodic Table provides element names and symbols. The element symbol for arsenic is "As".

Which subatomic particle is found in the nucleus and has no charge? A) Electron B) Neutron C) Proton D) Positron

B) Neutron Explanation: Neutrons are subatomic particles found in the nucleus that have no charge.

Which of the following sets of elements and symbols is paired correctly? A) rubidium, Ru B) indium, In C) thallium, Tm D) francium, Fm E) astatine, As

B) indium, In Explanation: The Periodic Table provides element names and symbols. The element symbol for indium is "In".

Write the chemical formula for bromine pentachloride

BrCl₅

The halogens are found in Group ____ A) 1A (1) B) 2A (2) C) 6A (16) D) 7A (17) E) 8A (18)

D) 7A (17)

Cathode rays are composed of what fundamental particle? A) Protons B) Neutrons C) Alpha particles D) Electrons E) Gamma rays

D) Electrons Explanation: Cathode rays are composed of electrons.

Which of the following elements would be chemically similar to selenium (Se)? A) Br B) Sc C) As D) S E) Ca

D) S Explanation: Elements that are in the same family (column) on the periodic table are chemically similar. S is in the same family as Se.

The element symbol for tungsten is _____ A) Tn B) Tu C) Ts D) W E) Te

D) W Explanation: The Periodic Table provides element names and symbols. The element symbol for tungsten is "W". The "W" comes from the name of mineral that contains the element, which is called wolframite.

What element has the symbol Br? A) barium B) bismuth C) bohrium D) bromine E) boron

D) bromine Explanation: The Periodic Table provides element names and symbols. Bromine has the chemical symbol "Br".

The symbol Cr represents the element _____ A) cerium B) californium C) curium D) chromium E) copernicium

D) chromium

The element symbol for copper is _____ A) C B) Cr C) Co D) Ce E) Cu

E) Cu Explanation: The Periodic Table provides element names and symbols. The element symbol for copper is "Cu". The "Cu" comes from the Latin word "cuprum" which indicates it is from the island of Cyprus, where copper is mined.

Which of the following is most likely to form a +2 ion? A) K B) Sc C) Al D) O E) Mg

E) Mg Explanation: Elements in Group 2 tend to form a +2 ion by losing its two valence electrons.

Which of the following sets of elements and symbols is paired correctly? A) potassium, P B) sodium, S C) copper, Co D) gold, Gd E) silicon, Si

E) silicon, Si Explanation: The Periodic Table provides element names and symbols. Silicon has the symbol "Si."

Write the chemical formula for iron(III) oxide

Fe₂O₃

Write the balanced COMPLETE ionic equation for the reaction when KI and AgNO₃ are mixed in aqueous solution. If no reaction occurs, simply write only NR.

K⁺(aq) + I⁻(aq) + Ag⁺(aq) + NO₃⁻(aq) → AgI(s) + K⁺(aq) + NO₃⁻(aq)

What is the correct IUPAC name for Mg₃P₂?

Magnesium phosphide

Write the chemical formula for magnesium hydrogen sulfite

Mg(HSO₃)₂

Write the chemical formula for the ammonium ion

NH₄⁺

Write the balanced NET ionic equation for the reaction when aqueous SrBr₂ and aqueous K₂SO₄ are mixed in solution to form solid SrSO₄ and aqueous KBr.

Sr²⁺(aq) + SO₄²⁻(aq) → SrSO₄(s)

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

Sulfurous acid

What is the correct IUPAC name for CuIO?

copper(I) hypoiodite

What is the correct IUPAC name for As₂S₅?

diarsenic pentasulfide

What is the correct IUPAC name for S₂F₈?

disulfur octafluoride

What is the correct IUPAC name for HNO₂(aq)?

nitrous acid

What is the correct IUPAC name for HClO₄(aq)?

perchloric acid

What is the correct IUPAC name for Ag₂S?

silver sulfide

What is the correct IUPAC name for Na₂SO₃?

sodium sulfite

What is the correct IUPAC name for P₄S₃?

tetraphosphorus trisulfide

What is the correct IUPAC name for SnSO₄?

tin(II) sulfate

What is the correct IUPAC name for Sn(ClO)₄?

tin(IV) hypochlorite

What is the correct IUPAC name for Fe₃P₂?

Iron (II) Phosphide

Which of the following elements would be chemically similar to calcium (Ca)? A) K B) Sr C) Sc D) S E) Ga

B) Sr Explanation: Elements that are in the same family (column) on the periodic table are chemically similar. Sr is in the same family as Ca.

The Millikan oil drop experiment determined: A) The mass of the electron B) The charge of the electron C) The mass of the proton D) Both (A) and (B)

B) The charge of the electron The Millikan oil drop experiment determined the charge of the electron.

What is the correct IUPAC name for PbF₂?

lead (II) fluoride

Write the chemical formula for the peroxide ion

O₂²⁻

Convert a pressure of 284.2 torr to atm.

0.3739 atm 284.2 torr(1 atm/760 torr)=0.3739 atm

What is the element symbol for titanium? A) Tm B) Ti C) Ta D) Tn E) T

B) Ti Explanation: The Periodic Table provides element names and symbols. The element symbol for titanium is Ti.

What is the correct IUPAC name for BaI₂?

barium iodide

What is the correct IUPAC name for Cr₂O₃?

chromium(III) oxide

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

cobalt(II) nitrite

In a 4.00 L pressure cooker, water is brought to a boil. If the final temperature is 115.0 °C at 4.15 atm, how many moles of steam are in the cooker?

0.521 mol Explanation: pV=nRT n=pV/RT n=(4.15atm)(4L)/(0.08206 L atm/mol K)(115+273.15)=0.521 mol

Which of the following is most likely to make a -3 ion? A) Al B) P C) Be D) Se E) Bi

B) P Explanation: An element that contains 5 electrons in its outer shell (Group 15) will be likely to gain three electrons to form a -3 ion and fill its octet.

What element with a mass number of 100 has 56 neutrons in its nucleus? A) Fermium (Fm) B) Ruthenium (Ru) C) Barium (Ba) D) Copernicium (Cn) E) Radium (Ra)

B) Ruthenium (Ru) Explanation: The mass number of an atom is representative of the number of protons and neutrons. Calculate the number of protons from the mass number and neutrons. 100=x+56 44=x Then, find the element in the periodic table that contains 44 protons. The number of protons is indicated by the atomic number. The element is Ruthenium (Ru).

Which element is classified as a transition metal? A) lithium (Li) B) zirconium (Zr) C) tellurium (Te) D) xenon (Xe)

B) zirconium (Zr) Explanation: Transition metals are found in columns 3-12 of the periodic table. Zirconium is a transition metal found in column 4.

Which of the following would be an isotope of ¹⁴N? A) ¹⁴C B) ¹⁶N C) ¹⁴O D) ¹⁶O E) All of the above

B) ¹⁶N Explanation: Isotopes are forms of the same element that differ in the number of neutrons but contain the same number of protons and electrons. ¹⁶N is an isotope of ¹⁴N.

What is the correct formula for barium phosphate? A) BaPO₄ B) Ba₂PO₄ C) Ba₂(PO₄)₃ D) Ba₃(PO₄)₂

Ba₃(PO₄)₂ Explanation: Barium forms ions with a +2 charge and the phosphate polyatomic ion has a -3 charge. It would take three barium ions to balance the charge of two phosphate ions. This is the lowest number of each ion to reach a neutral formula unit.

Determine the correct formula for chromium(II) nitrite. A) CrNO₂ B) Cr₂NO₂ C) Cr(NO₂)₂ D) Cr₃(NO₂)₂

C) Cr(NO₂)₂ Explanation: The (II) in chromium(II) nitrite indicates that the chromium ion has a 2+ charge. Nitrite is a polyatomic ion that has a -1 charge. Two nitrite ions would be needed to balance the charge on the chromium ion.

Which scientist determined the charge of the electron? A) John Dalton B) J. J. Thomson C) Robert Millikan D) Ernest Rutherford E) James Chadwick

C) Robert Millikan Explanation: Robert Millikan determined the charge of the electron in 1909 during his oil drop experiment.

What is the correct IUPAC name for IF₅?

iodine pentafluoride

What is the correct IUPAC name for IrBr₄?

iridium(IV) bromide

Complete the balanced molecular chemical equation for the reaction below. If no reaction occurs, write NR after the reaction arrow.

(NH₄)₂SO₄(aq) + BaCl₂(aq) → BaSO₄(s) + 2 NH₄Cl(aq)

Predict the chemical formula for the ionic compound formed by NH₄⁺ and PO₄³⁻

(NH₄)₃PO₄

What is the mass in grams of Al that were reacted with excess HCl if 2.92 L of hydrogen gas were collected at STP in the following reaction? 2 Al (s) + 6 HCl (aq) → 2 AlCl₃ (aq) + 3 H₂ (g)

2.34 g Explanation: pV=nRT n=pV/RT n=(1.00 atm)(2.92L)/(0.08206 L atm/mol K)(273.15K) n=0.1303 mol H2 0.1302 mol H2(2 mol Al/3 mol H2)(26.98 g H2/1 mol Al)=2.34g Al

Write the balanced NET ionic equation for the reaction when AlCl₃ and Na₂S are mixed in aqueous solution. If no reaction occurs, simply write only NR.

2 Al³⁺(aq) + 3 S²⁻(aq) → Al₂S₃ (s)

Complete the balanced dissociation equation for the compound below in aqueous solution. If the compound does not dissociate, write NR after the reaction arrow.

Al₂(SO₄)₃(s) → 2 Al³⁺(aq) + 3 SO₄²⁻(aq)

What is the correct IUPAC name for K₂O

Potassium oxide

What is the formula for an ionic compound containing Ba²⁺ ions and Cl⁻ ions? A) BaCl B) Ba₂Cl C) BaCl₂ D) BaCl₃ E) Ba₃Cl

C) BaCl₂ Explanation: Two ions of chlorine are needed to balance out the positive charge on the barium ion.

The element symbol for potassium is _____ A) P B) Po C) K D) Kr E) Pa

C) K Explanation: The Periodic Table provides element names and symbols. The element symbol for potassium is K. The "K" comes from the Latin word "kalium" which translates to potash.

Which subatomic particle is found in the nucleus and has a positive charge? A) Electron B) Neutron C) Proton D) Positron

C) Proton Explanation: Protons are subatomic particles found in the nucleus that have a positive charge.

The element symbol for tin is _____ A) Sb B) Ti C) Sn D) Tn E) Te

C) Sn Explanation: The Periodic Table provides element names and symbols. The element symbol for tin is "Sn". The "Sn" comes from the Latin word "stannum" which translates to mean "to drip".

Which element is classified as a noble gas? A) hydrogen (H) B) oxygen (O) C) bromine (Br) D) neon (Ne)

D) neon (Ne) Explanation: Noble gases are found in column 18 of the periodic table. Neon is a noble gas.

The symbol Se represents the element ______. A) samarium B) silicon C) sulfur D) selenium E) cerium

D) selenium Explanation: The Periodic Table provides element names and symbols. The symbol for selenium is "Se".

Which of the following sets of elements and symbols is paired correctly? A) beryllium, B B) manganese, Mg C) calcium, Cm D) tungsten, W E) lead, La

D) tungsten, W Explanation: The Periodic Table provides element names and symbols. Tungsten has the element symbol "W". Tungsten was originally named wolfram because it was named for the mineral wolframite it is found in.

Which of the following elements is represented by a single-letter element symbol? A) rubidium B) chlorine C) plutonium D) vanadium E) molybdenum

D) vanadium Explanation: The Periodic Table provides element names and symbols. The symbol for vanadium is "V".

Iron forms compounds as both a ferrous Fe(II) and a ferric Fe(III) ion. These two ions differ by: A) 1 proton B) 1 neutron C) 2 protons D) 2 electrons E) 1 electron

E) 1 electron Explanation: A ferrous (Fe²⁺) ion has one more electron than a ferric (Fe³⁺) ion.

Complete the balanced dissociation equation for the compound below in aqueous solution. If the compound does not dissociate, write NR after the reaction arrow.

NaBr(s) → Na⁺(aq) + Br⁻(aq)

Complete the balanced molecular chemical equation for the reaction below. If no reaction occurs, write NR after the reaction arrow.

NaNO₃(aq) + LiCl(aq) →NR Explanation: NaNO3 (aq) + LiCl (aq) → NaCl (aq) + LiNO3 (aq) No rxn

Write the chemical formula for nickel(II) iodide

NiI₂

Write the balanced molecular chemical equation for the reaction in aqueous solution for lead(II) nitrate and sodium chloride. If no reaction occurs, simply write only NR.

Pb(NO₃)₂(aq) + 2 NaCl(aq) → PbCl₂(s) + 2 NaNO₃(aq)

Write the chemical formula for diphosphorus pentabromide

P₂Br₅

Write the balanced NET ionic equation for the reaction when aqueous MgSO₄ and aqueous Ba(NO₃)₂ are mixed in solution to form aqueous Mg(NO₃)₂ and solid BaSO₄.

SO₄²⁻(aq) + Ba²⁺(aq) → BaSO₄(s)

Write the chemical formula for selenium hexafluoride

SeF₆

Predict the chemical formula for the ionic compound formed by V³⁺ and NO₂⁻

V(NO₂)₃

What is the correct IUPAC name for CsHSO₃?

cesium hydrogen sulfite

What is the correct IUPAC name for CoCl₂ ?

cobalt(II) chloride

What is the correct IUPAC name for LiHSO₄?

lithium hydrogen sulfate

What is the correct IUPAC name for Al(NO₂)₃?

aluminum nitrite

What mass of precipitate (in g) is formed when 45.5 mL of 0.300 M K₃PO₄ reacts with 53.0 mL of 0.200 M Cr(NO₃)₃ in the following chemical reaction? K₃PO₄(aq) + Cr(NO₃)₃(aq) → CrPO₄(s) + 3 KNO₃(aq)

1.56 g Explanation: Limiting reactant problem 45.5 mL(0.300 mol K₃PO₄/1000 mL)(1 mol CrPO₄/1 mol K₃PO₄)(146.97g CrPO₄/1 mol CrPO₄)=2.01 g CrPO₄ 53.0 mL(0.200 mol Cr(NO₃)₃/1000 mL)(1 mol CrPO₄/1 mol Cr(NO₃)₃)(146.97g CrPO₄/1 mol CrPO₄)=1.56 g CrPO₄

How many protons are in an atom of Ni?

28

Write the balanced molecular chemical equation for the reaction in aqueous solution for iron(III) chloride and sodium sulfide. If no reaction occurs, simply write only NR.

2FeCl₃(aq) + 3Na₂S(aq) → Fe₂S₃(s) + 6NaCl(aq)

Complete the balanced molecular chemical equation for the reaction below. If no reaction occurs, write NR after the reaction arrow.

3 Cu₂SO₄(aq) + 2 Na₃PO₄(aq) → 2 Cu₃PO₄(s) + 3 Na₂SO₄(aq)

Complete the balanced molecular chemical equation for the reaction below. If no reaction occurs, write NR after the reaction arrow.

3 KOH(aq) + AlCl₃(aq) → Al(OH)₃(s) + 3 KCl(aq)

If 34.0 g of NaOH is added to 0.550 L of 1.00 M Ni(NO₃)₂, how many grams of Ni(OH)₂ will be formed in the following precipitation reaction? 2 NaOH(aq) + Ni(NO₃)₂(aq) → Ni(OH)₂ (s) + 2 NaNO₃ (aq)

39.4 g Explanation: Limiting reactant problem 34.0g NaOH (1 mol NaOH/40g NaOh)=0.85 mol NaOH 0.550L(1 mol Ni(NO₃)₂/1L Ni(NO₃)₂=0.550 mol Ni(NO₃)₂ 0.85 mol NaOH(1 mol Ni(OH)₂/2 mol NaOH)((92.71g Ni(OH)2/1 mol Ni(OH)2)=39.4g Ni(OH)2 0.550 mol Ni(NO₃)₂(1 mol Ni(OH)₂/1 mol Ni(NO₃)₂)(92.71g Ni(OH)2/1 mol Ni(OH)2)=51.0g Ni(OH)2

What pressure in kPa is equivalent to 0.400 atm?

40.5 kPa 0.400 atm(101325 Pa/1 atm)(1 kPa/1000 Pa)=40.5 kPa

What is the mass number for an atom of calcium containing 20 protons and 28 neutrons?

48

A 1.20 L weather balloon on the ground has a temperature of 25.0°C and is at atmospheric pressure (1.00 atm). When it rises to an elevation where the pressure is 0.730 atm, then the new volume is 1.80 L. What is the temperature (in °C) of the air at this elevation?

53 °C Explanation: The combined gas law is: P1V1/T1=P2V2/T2 (1.00 atm)(1.20 L)(25.0+273.15)=(0.730 atm)(1.80 L)/T2 T2=326.15-273.15=53 C

What is the atomic number for an element whose mass number is 138, which contains 81 neutrons per atom?

57

What is the mass number for an atom of nickel containing 28 protons and 36 neutrons?

64

What is the element symbol for gold? A) Au B) Am C) Al D) A E) An

A) Au Explanation: The Periodic Table provides element names and symbols. The element symbol for gold is Au. The "Au" comes from the Latin word "aurum" which means "shining dawn."

What is the atomic symbol for the element in Group 5A (15) and the fifth period? A) As B) Sb C) Sn D) Te E) Bi

B) Sb Explanation: The element that is found in the fifth row of Group 5A (15) is Sb.

A mass spectrometer measures neon to have two masses: 20 and 22 atomic mass units. These are: A) Isotopes B) Ions C) Compounds D) None of the above

A) Isotopes Explanation: Isotopes are forms of the same element that differ in the number of neutrons but contain the same number of protons. This yields atoms of the same element that have different masses.

Which of the following elements is NOT a metal? A) arsenic B) indium C) iridium D) lithium E) lutetium

A) arsenic Explanation: Arsenic is an element on the "staircase" on the Periodic Table, making it a metalloid, not a metal.

Which element is classified as a halogen? A) chlorine (Cl) B) oxygen (O) C) sulfur (S) D) argon (Ar)

A) chlorine (Cl) Explanation: Halogens are found in column 17 of the periodic table. Chlorine is a halogen.

Which of the following sets of elements and symbols is not a correct match? A) nitrogen, Ni B) fluorine, F C) chlorine, Cl D) phosphorus, P E) silicon, Si

A) nitrogen, Ni Explanation: The Periodic Table provides element names and symbols. The element symbol for nitrogen is "N" and the element symbol "Ni" represents nickel.

The symbol Sr represents the element _____ A) strontium B) sulfur C) selenium D) samarium E) seaborgium

A) strontium Explanation: The Periodic Table provides element names and symbols. Strontium has the element symbol "Sr".

What is the formula for an ionic compound containing Sc³⁺ and O²⁻ ions? A) Sc₂O B) Sc₂O₃ C) ScO₃ D) ScO₂

B) Sc₂O₃ Explanation: Two scandium (+3) ions are needed to balance the negative (-2) charges on the three oxide ions. This is the lowest number of each ion to reach a neutral formula unit.

Write the chemical formula for silver sulfate

Ag₂SO₄

Write the chemical formula for aluminum perbromate

Al(BrO₄)₃

Write the chemical formula for gold(III) cyanide

Au(CN)₃

An atom has nine protons and ten electrons. This makes it: A) Nonstoichiometric B) An ion C) A cathode ray D) An alpha particle E) Neutrally charged

B) An ion Explanation: A neutral atom has an equal number of protons and electrons. If there are more or less of one than the other, the atom is an ion.

Write the balanced COMPLETE ionic equation for the reaction when aqueous BaCl₂ and aqueous (NH₄)₂SO₄ are mixed in solution to form aqueous NH₄Cl and solid BaSO₄. If no reaction occurs, simply write only NR.

Ba²⁺(aq) + 2 Cl⁻(aq) + 2 NH₄⁺(aq) + SO₄²⁻(aq) → 2 NH₄⁺(aq) + 2 Cl⁻(aq) + BaSO₄(s)

Write the balanced COMPLETE ionic equation for the reaction when barium chloride and zinc sulfate are mixed in aqueous solution. If no reaction occurs, simply write only NR.

Ba²⁺(aq) + 2Cl⁻(aq) + Zn²⁺(aq) + SO₄²⁻(aq) → BaSO₄(s) + Zn²⁺(aq) + 2Cl⁻(aq)

Which of the following sets of elements and symbols is paired correctly? A) barium, Br B) arsenic, Ac C) iodine, I D) francium, F E) cadmium, Cm

C) iodine, I Explanation: The Periodic Table provides element names and symbols. Iodine has the symbol "I."

Neutral atoms of all isotopes of a given element have the same A) number of protons and neutrons B) number of neutrons C) number of electrons D) mass numbers E) masses

C) number of electrons Isotopes are forms of the same element that differ in the number of neutrons but contain the same number of protons and electrons.

Which of the following sets of elements and symbols is paired incorrectly? A) lithium, Li B) arsenic, As C) silver, Si D) gallium, Ga E) zinc, Zn

C) silver, Si Explanation: The Periodic Table provides element names and symbols. Silver has the element symbol "Ag". It was originally named argentum.

Write the chemical formula for calcium chloride

CaCl₂

What is the correct IUPAC name for Ca(BrO₂)₂?

Calcium bromite

Write the chemical formula for cobalt(II) hydrogen carbonate

Co(HCO₃)₂

Write the chemical formula for chromium(III) cyanide

Cr(CN)₃

What element has the symbol Ge? A) gallium B) gold C) georgium D) roentgenium E) germanium

E) germanium Explanation: The Periodic Table provides element names and symbols. Germanium has the element symbol "Ge".

Which of the following sets of elements and symbols is a correct match? A) niobium, Ni B) platinum, Pm C) rhenium, Rh D) palladium, Pa E) molybdenum, Mo

E) molybdenum, Mo Explanation: The Periodic Table provides element names and symbols. The element symbol for molybdenum is "Mo".

Write the chemical formula for hydrobromic acid

HBr

Write the chemical formula for hypobromous acid

HBrO

Write the formula for nitrous acid

HNO₂

Write the formula for sulfurous acid

H₂SO₃