Question 1

On the periodic table, there is a family of elements that are not very reactive but do form compounds under special conditions. The elements in this family are referred to as&#10;A) noble gases.&#10;B) transition metals.&#10;C) alkaline metals.&#10;D) radioactive.

Accepted Answer

Certain elements are unreactive and will not combine with other elements to give compounds; these elements are all members of the eighth group shown in the periodic table and constitute a family. They all exist in the gaseous state under normal conditions and, being inert, are commonly referred to as the noble gases.

Question 2

The pH of a solution is determined to be 6. This solution would be considered&#10;A) neutral.&#10;B) acidic.&#10;C) basic.&#10;D) water.

Accepted Answer

Any solution in which [H₃O⁺] is equal to [OH^-] must be neutral, and any solution in which [OH^-] and [H₃O⁺] are unequal must be either basic or acidic. The concentration of H₃O⁺ is expressed as moles/liter and is commonly expressed in terms of pH (from the French phrase puissance d'hydrogene, meaning "power of hydrogen") as a number between 0 and 14. For those solutions in which [H₃O⁺] is larger than 10^-7, the solution will contain a concentration of H₃O⁺ ions greater than that of OH^- ions, and will therefore be acidic. Whenever the [H₃O⁺] is greater than [OH^-], the pH will be less than 7, and for those solutions in which the [H₃O⁺] is less than [OH^-], the pH will be greater than 7 and the solution will be basic.

Question 3

A buffer solution&#10;A) helps maintain pH.&#10;B) is necessary for a neutralization reaction.&#10;C) is necessary for the suspension of colloids.&#10;D) is important in redox reactions.

Accepted Answer

A means by which pH limits can be maintained is referred to as buffering and involves a solution that contains a mixture-some that are acidic and others that are basic.

Question 4

The atomic number of an element is defined as the&#10;A) number of neutrons in an atom.&#10;B) atomic mass of an atom.&#10;C) number of protons in an atom.&#10;D) the number of protons minus the number of neutrons.

Accepted Answer

The number above a chemical symbol is the atomic number (Z number) of the element, and the number below a chemical symbol is the average atomic mass (A number) of the element. Z number indicates the number of protons.

Question 5

The equation used for calculation of the quantity of an acid or base in a given sample is A) C₁V₁=C₂V_2. B) V₁N₁=V₂N_2. C) C₁V₁²=C₂V₂². D) V₁N₁²=V₂N₂².

Accepted Answer

This is a useful relationship for calculation of the quantity of an acid or base: V₁ = Volume of the standard solution (prepared in the laboratory) N₁ = Normality of the standard solution V₂ = Volume of the unknown solution N₂ = Normality of the unknown solution

Question 6

In the chemical symbol ^ZX_A, the A number is A) the number of protons and neutrons. B) the number of protons and electrons. C) the number of protons minus the number of electrons. D) the number of neutrons minus the number of protons.

Accepted Answer

The atomic mass minus the atomic number gives the number of neutrons present in the nucleus. The atomic mass is the sum of the protons and neutrons.

Question 7

Avogadro's number is&#10;A) the ratio of the weight of each element in a compound.&#10;B) equal to the atomic mass of an element.&#10;C) the number of atoms or molecules in 1 gaw or gmw.&#10;D) the electron configuration of an element.

Accepted Answer

One gram molecular weight (1 gmw) of any two substances will contain the same number of atoms or molecules. The number of atoms or molecules in 1 gram atom weight (1 gaw) or gmw has been shown by experiment to be 6.02 F1F1F1S1F1F1F10 10²³. This number is called Avogadro's number, and 1 gaw or gmw of any substance is commonly referred to as 1 mole.

Question 8

The chemical properties of a substance may be affected by a change in conditions. If this occurs, the change will&#10;A) result in the formation of one or more &#34;new&#34; substances.&#10;B) exhibit the initial properties of the substance.&#10;C) always be irreversible.&#10;D) result in a change of the physical state of the substance.

Accepted Answer

A chemical change always results in the formation of one or more "new" substances, each of which has unique chemical and physical properties.

Question 9

A solution is a homogeneous mixture&#10;A) of two substances.&#10;B) of particles and a solute.&#10;C) of particles and a solvent.&#10;D) of a substance and a ligand.

Accepted Answer

A solution by definition is a homogeneous mixture of two or more substances. The solute can be a gas, liquid, or solid, and the solvent is generally a liquid.

Question 10

A colloid is a type of mixture in which&#10;A) the particles are aerosolized.&#10;B) the particles settle and result in a layered mixture.&#10;C) the particles remain suspended in the dispersing medium indefinitely.&#10;D) all of the particles are of equal size and shape.

Accepted Answer

Dispersed colloid particles remain suspended in the dispersing medium indefinitely; the behavior is attributed to a constant bombardment of the dispersed particles by the molecules of the dispersing medium; thus, the colloid particles are in constant motion. The phenomenon is called the Brownian movement.

Question 11

Titrations are procedures in which&#10;A) an accurately measured but unknown volume of solution must be determined.&#10;B) an accurate volume of a known substance must be determined.&#10;C) an accurate volume of a ligand must be determined and measured.&#10;D) an accurate volume is used to determine an unknown redox reaction.

Accepted Answer

The answer of Titrations are procedures in which&#10;A) an accurately...

Question 12

Atoms that differ only in the number of neutrons present in the nucleus are called&#10;A) isomers.&#10;B) isotones.&#10;C) isotopes.&#10;D) isomorphs.

Accepted Answer

The answer of Atoms that differ only in the number...

Question 13

A characterization of a weak acid is that it&#10;A) completely dissociates in water.&#10;B) does not completely dissociate in water.&#10;C) needs a buffer water.&#10;D) neutralizes water.

Accepted Answer

The answer of A characterization of a weak acid is...

Question 14

Which type of compound is held together by purely electrostatic forces?&#10;A) Ionic&#10;B) Covalent&#10;C) Constant&#10;D) Cooperative

Accepted Answer

The answer of Which type of compound is held together...

Question 15

The products of a neutralization reaction are&#10;A) an acid and a base.&#10;B) salt and water.&#10;C) a chelate and a ligand.&#10;D) a standard solution.

Accepted Answer

The answer of The products of a neutralization reaction are&#10;A)...

Question 16

Each family of simple organic compounds is characterized by a functional group that determines&#10;A) the number of covalent bonds necessary for interactions within the family.&#10;B) the number of aromatic rings for each family.&#10;C) their location on the periodic table.&#10;D) the chemical reactions that all members of the family undergo.

Accepted Answer

The answer of Each family of simple organic compounds is...

Question 17

A compound, regardless of its origin or method of preparation, always contains the same elements in the same proportions by weight; this is called&#10;A) the law of constant composition.&#10;B) the law of multiple proportions.&#10;C) a complex ion.&#10;D) a ligand.

Accepted Answer

The answer of A compound, regardless of its origin or...

Question 18

Sharing of electrons between two bonded elements forms a(an)&#10;A) ionic bond.&#10;B) covalent bond.&#10;C) coordinate bond.&#10;D) cooperative bond.

Accepted Answer

The answer of Sharing of electrons between two bonded elements...

Question 19

The physical properties of a substance may be affected by a change in conditions. If this occurs, when the substance returns to its original condition, the physical properties&#10;A) result in the formation of one or more &#34;new&#34; substances.&#10;B) will be the same as the initial properties.&#10;C) will still be different because they cannot have their change reversed.&#10;D) result in a change of physical state.

Accepted Answer

The answer of The physical properties of a substance may...

Question 20

The Pauli exclusion principle states that&#10;A) no electrons can be in the nucleus.&#10;B) no two electrons can have the same set of quantum numbers.&#10;C) only one electron can occupy the same orbital.&#10;D) no electron can be at a subenergy level.

Accepted Answer

The answer of The Pauli exclusion principle states that&#10;A) no...

Question 21

What is the simplest aromatic compound?&#10;A) Benzene&#10;B) Ethene&#10;C) Ethanol&#10;D) Methane

Accepted Answer

The answer of What is the simplest aromatic compound?&#10;A) Benzene&#10;B)...

Question 22

All of the following are types of organic compounds, EXCEPT&#10;A) halides.&#10;B) amines.&#10;C) acids.&#10;D) alkenes.

Accepted Answer

The answer of All of the following are types of...

Question 23

Nitrate has a&#10;A) neutral charge.&#10;B) -3 charge.&#10;C) +1 charge.&#10;D) -1 charge.

Accepted Answer

The answer of Nitrate has a&#10;A) neutral charge.&#10;B) -3 charge.&#10;C)...

Question 24

All of the following organic compounds are used in radiopharmaceuticals, EXCEPT&#10;A) arenes.&#10;B) alcohols.&#10;C) phenols.&#10;D) esters.

Accepted Answer

The answer of All of the following organic compounds are...

Deck 3: Chemistrybiochemistry