chem review

Which radioisotope emits alpha particles?

Pu-239

Properties of nonmetal atoms include

high ionization energy and high electronegativity

As ice melts at standard pressure, its temperature remains at 0°C until it has completely melted. Its potential energy

increases

As the atmospheric pressure increases, the temperature at which water boils in an open vessel

increases

A compound is made up of iron and oxygen, only. The ratio of iron ions to oxide ions is 2:3 in this compound. The IUPAC name for this compound is

iron(III) oxide

Which two characteristics are associated with metals?

low first ionization energy and low electronegativity

Which element is a metal that is in the liquid phase at STP?

mercury

Which characteristics both generally decrease when the elements in Period 3 on the Periodic Table are considered in order from left to right?

metallic properties and atomic radius

A correct name for N2O3 is

nitrogen (III) oxide

Which atom contains exactly 15 protons?

phosphorus-32

When an atom of lithium loses an electron, the atom becomes a

positive ion with a radius smaller than the radius of the atom

The stability of an isotope is based on its

ratio of neutrons to protons

Which element has the highest melting point?

rhenium

Given the balanced equation representing a reaction: 4Al(s) + 3O2(g) 2Al2O3(s) Which type of chemical reaction is represented by this equation?

synthesis

What is the density of N2 at STP?

.00125 g/cm

The total number of moles represented by 20 grams of CaCO3 is

0.2

The number of atoms in a molecule of helium is

1

Which quantity of particles is correctly represented by the formula H2SO4?

1.0 mole of molecules

What is the total number of electron pairs shared between the two atoms in an O2 molecule?

2

Which electron configuration represents an atom of an element having a completed third principal energy level?

2-8-18-2

Given the balanced equation representing a reaction: 4NH3 + 5O2 4NO + 6H2O What is the minimum number of moles of O2 that are needed to completely react with 16 moles of NH3?

20. mol

What is the total number of atoms represented in the formula CuSO4 • 5H2O?

21

When 200 grams of water cools from 50.°C to 25°C, the total amount of heat energy released by the water is

21 kJ

At 25ºC, gas in a rigid cylinder with a movable piston has a volume of 145 mL and a pressure of 125 kPa. Then the gas is compressed to a volume of 80. mL. What is the new pressure of the gas if the temperature is held at 25ºC?

230 kPa

A 100.00-gram sample of naturally occurring boron contains 19.78 grams of boron-10 (atomic mass = 10.01 atomic mass units) and 80.22 grams of boron-11 (atomic mass = 11.01 atomic mass units). Which numerical setup can be used to determine the atomic mass of naturally occurring boron?

(0.1978)(10.01) + (0.8022)(11.01)

Based on Reference Table N, what fraction of a radioactive 90Sr sample would remain unchanged after 56.2 years?

1/4

The temperature of a sample of water changes from 10°C to 20°C when the sample absorbs 418 joules of heat. What is the mass of the sample

10g

According to Reference Table H, what is the boiling point of ethanoic acid at 80 kPa?

111°C

At 1 atmosphere of pressure, 25.0 grams of a compound at its normal boiling point is converted to a gas by the addition of 34,400 Joules. What is the heat of vaporization for this compound, in Joules per gram?

1376 J/g

What is the gram-formula mass of (NH4)3PO4?

149 g/mol

Which group in the Periodic Table contains elements that are all monatomic gases at STP?

18

What is the total number of kiloJoules of heat energy absorbed when the temperature of 200 grams of water is raised from 10ºC to 40ºC?

25.2 kJ

What is the percent composition by mass of sulfur in the compound MgSO4 (gram-formula mass = 120. grams per mole)?

27%

What is the total number of moles of sulfur atoms in 1 mole of Fe2(SO4)3?

3

A 36-gram sample of water has an initial temperature of 22°C. After the sample absorbs 1200 joules of heat energy, the final temperature of the sample is

30.°C

An original sample of the radioisotope fluorine-21 had a mass of 80.0 milligrams. Only 20.0 milligrams of this original sample remain unchanged after 8.32 seconds. What is the half-life of fluorine-21?

4.16s

What is the total mass in grams of 0.75 mole of SO2?

48g

What is the minimum amount of heat required to completely melt 20.0 grams of ice at its melting point?

6,680 J

Given the balanced equation representing a reaction: C3H8(g) +5O2(g) 3CO2(g) + 4H2O(g) What is the total number of moles of O2(g) required for the complete combustion of 1.5 moles of C3H8(g)?

7.5 mol

A 1.0-mole sample of krypton gas has a mass of

84g

Which statement explains why sulfur is classified as a Group 16 element?

A sulfur atom has 6 valence electrons.

Which statement describes the relative energy of the electrons in the shells of a calcium atom?

An electron in the third shell has more energy than an electron in the second shell

Which statement identifies the element arsenic?

Arsenic has an atomic number of 33

Given the balanced equation: X + Cl2 C2H5Cl + HCl Which molecule is represented by X?

C2H6

Which ionic compound dissolves in water to form a colored solution?

Cu(NO3)2

What is the chemical formula for copper(II) hydroxide?

Cu(OH)2

Which formula represents copper(I) oxide?

Cu2O

Which of the following ions has the smallest radius

F-

What is the chemical formula for iron(III) oxide?

Fe2O3

Which ion has no electrons?

H+

Which formula represents a homogeneous mixture?

HCl(aq)

In which compound is the percent composition by mass of chlorine equal to 42%?

HClO3 (gram-formula mass = 84 g/mol)

What occurs when a 35-gram aluminum cube at 100°C is placed in 90. grams of water at 25°C in an insulated cup?

Heat is transferred from the aluminum to the water, and the temperature of the water increases.

Which equation represents sublimation?

I2(s) to I2(g)

Which two solutions, when mixed together, will undergo a double replacement reaction and form a white, solid substance?

KCl(aq) and AgNO3(aq)

In the ground state, which element's atoms have five completely filled orbitals?

Ne

Which list includes elements with the most similar chemical properties?

O, S, Se

Which radioisotope is matched with its decay mode?

P-32 and B-

According to Table F, which of these salts is least soluble in water?

PbCl2

Which trends are observed when the elements in Period 3 on the Periodic Table are considered in order of increasing atomic number?

The atomic radius decreases, and the first ionization energy generally increases.

As the elements Li to F in Period 2 of the Periodic Table are considered in succession, how do the relative electronegativity and the covalent radius of each successive element compare?

The relative electronegativity increases, and the atomic radius decreases.

According to Reference Table G, how does a decrease in temperature from 40°C to 20°C affect the solubility of NH3 and KCl?

The solubility of NH3 increases, and the solubility of KCl decreases

A solution consists of 0.50 mole of CaCl2 dissolved in 100. grams of H2O at 25°C. Compared to the boiling point and freezing point of 100. grams of H2O at standard pressure, the solution at standard pressure has

a higher boiling point and a lower freezing point

Which phrase describes an atom?

a positively charged nucleus surrounded by negatively charged electrons

Which precipitate does the following reaction form? Ba(NO3)2(aq) + Na2SO4(aq) 2 NaNO3(aq) + BaSO4(s),

barium sulfate

Which polyatomic ion contains the greatest number of oxygen atoms?

carbonate

The two forms of oxygen, O2(g) and O3(g), have

different molecular structures and different properties

Which sequence represents a correct order of historical developments leading to the modern model of the atom?

the atom is a hard sphere → most of the atom is empty space → electrons exist in orbitals outside the nucleus

Which process increases the potential energy of the particles of a sample?

vaporization