CHEM 1411 - Ch 8 Part B

2S (s) + 3O2 (g) → 2SO3 (g) Which of the following gives the correct setup for calculating the number of moles of SO3 that will form from the complete reaction of 1.5 mol of O2, according to the balanced reaction equation above?

(1.5×2) / 3

Unlike most metals, lithium and magnesium both react with N2 to form ionic nitrides. Which of the following observed relationships in the periodic table does this illustrate?

Diagonal relationships are often observed between Period 2 elements in Groups 1A, 2A, and 3A and the elements diagonally below them in Period 3.

Which of the formulas below represent halogen compounds that are actually likely to exist?

KI BrCl HF

Which of the noble gases form stable oxides or halides? Select all that apply.

Kr Xe

Which Group 15 elements are classified as nonmetals? Select all that apply.

N P

Which of the formulas below represent compounds of oxygen that are likely to exist?

SO2 Na2O KO2

Which statement below about Group 14 (4A) elements is NOT correct?

The most stable cation of germanium is Ge2+.

The noble gases are generally unreactive. Which statement best explains this observation?

The noble gases have high ionization energies and negative electron affinities, so they usually neither lose nor gain electrons.

Place the halogens in order of decreasing reactivity (e.g., with hydrogen, as shown below). Place the most reactive element at the top. X2 + H2 → 2HX

1. F2 2. Cl2 3. Br2 4. I2

Rank the elements below in order of their metallic character, with the least metallic at the top of the list.

1. N 2. P 3. As 4. Bi

Match each type of reaction yield with the correct definition. 1. Theoretical yield 2. Actual yield 3. Percent yield

1. The maximum possible amount of product calculated from the molar ratio in the balanced chemical equation. 2. Amount of product obtained experimentally from a chemical reaction 3. [(amount of product obtained) / (amount of product possible)] * 100

Correctly order the steps necessary to solve for the mass of a product, or second reactant required, given the mass of one of the reactants in a chemical process. Start with the first step at the top of the list.

1. Write a balance equation for the reaction 2. Convert the given mass into moles using molar mass. Convert moles of A to moles of B using a conversion factor derived from the balanced equation. 3. Convert the moles of the second substance to mass using its molar mass.

B2 + 2AB → 2AB2 In the balanced reaction equation above, if 1.0 moles of B2 and 1.5 moles of AB are allowed to react to completion, what is the maximum amount of AB2 that can form?

1.5 moles

Which of the following statements exemplifies a diagonal chemical relationship between elements of the periodic table?

Boron and silicon both act as semiconductors.

A chemical equation is a statement using chemical ___ that expresses both the identities and the relative ___ of the reactants and products involved in a chemical or physical change.

formulas; quantity

The ___ reactant in a reaction is one that limits the amount of product formed. This reactant will be completely used up in the reaction. Any reactants that are not used up are said to be ___ reactants.

limiting; excess

Although elements in Group 13 of the periodic table typically form ions with a charge of +3, some members of the group also form ions with a charge of ______.

+1

Which of the statements below, concerning periodic trends in the properties of elements, are correct?

-All elements in Group 17 form -1 ions. -Elements with low ionization energies tend to form positive ions. -Elements in Period 2 tend to have somewhat different properties from the rest of the elements in their groups.

Which of the following statements correctly describe halogens, which are found in Group 17 of the periodic table? Select all that apply.

-As pure elements, most halogens form diatomic molecules. -Halogens have high ionization energies and readily form negative ions. -The commonly occurring halogens are all nonmetals.

Select all the statements that correctly describe the properties of the Group 15 elements.

-Both nitrogen and phosphorus combine with oxygen to form oxides. -Nitrogen forms the ion N3- in binary ionic compounds. -Bismuth is the only metal in the group.

Select all the statements that correctly compare the behavior of Group 1 and Group 11 elements.

-Group 1 and 11 elements have similar outer electron configurations. -Group 11 elements are much less reactive than Group 1 elements. -Group 11 elements have higher ionization energies than Group 1 elements.

Which of the following statements describe hydrogen correctly? Select all that apply.

-Hydrogen can form compounds in which it has a -1 charge. -Hydrogen exists as a diatomic molecule on Earth.

Select all the statements that correctly describe the properties of the Group 16 elements.

-In its elemental form, oxygen forms O2 molecules, whereas sulfur forms S8 molecules. -Oxygen forms a large number of molecular compounds with other nonmetals.

Which of the following statements correctly describe the Group 13 elements? Select all that apply.

-Most of the Group 13 elements are metals. -Boron is unreactive with water and oxygen.

Select all the statements that correctly describe Group 14 elements.

-Sn and Pb react with acids to produce hydrogen gas. -Sn and Pb form cations with charges of +2 and +4. -Group 14 elements do not react readily with H2O.

Select all of the statements below that correctly describe the Group 1 metals.

-The alkali metals are reactive with water and oxygen. -Some of the alkali metals can combine with oxygen to form compounds with the formulas M2O, M2O2, and MO2. -Hydrogen is not included in the classification "alkali metals."

Which of the following statements correctly describe the limiting reactant in a reaction? Select all that apply.

-The limiting reactant limits the amount of product that can form. -The maximum amount of product formed is the amount that can be formed from the limiting reactant.

Which of the following statements describe the information that can be gained from a balanced chemical equation? Select all that apply.

-The physical states of reactants and products, usually. -The relative quantities (moles) of the substances involved. -The identities of substances involved.

Which of the following steps would be required to convert between the masses of two substances that are related through a chemical reaction? (For example, calculating the mass of product formed from the mass of a reactant.) Select all that apply.

-Write a balanced chemical equation for the reaction. -Convert from the given mass to moles of the same substance. -Write a conversion factor using the coefficients from the balanced equation, and convert to moles of the second substance.

Given the balanced equation below, determine the moles of HCl required and the mass of AgCl formed from the complete reaction of 18.3 g of Ag2S. Ag2S (s) + 2HCl (aq) → 2AgCl (s) + H2S (g)

0.148 mol HCl 21.2 g of AgCl

Match each element to the charges of its common cations. 1. Aluminum, Al 2. Indium, In 3. Lead, Pb

1. +3 only 2. both +1 and +3 3. both +2 and +4

In an experiment, a student calculates the maximum expected yield of her product to be 3.2 grams. However, when she weighs the purified product, she finds that she only has 2.8 grams, or only 88% of the maximum expected. Match each type of yield to its numerical value. 1. Theoretical yield 2. Actual yield 3. Percent yield

1. 3.2 2. 2.8 3. 88

3H2 (g) + N2 (g) → 2NH3 (g) Calculate the mass of NH3 produced by the complete reaction of 2.55 g of H2 with excess N2 according to the equation above.

14.4 g

Select all the conversion factors that correctly represent the molar relationships in this balanced equation 2Al + 3Cl2 → 2AlCl3.

2 mol Al / 3 mol Cl2 2 mol AlCl3 / 2 mol Al

A + 2B → C Reactants A (blue) and B (red) react according to the balanced equation above. Which of the following statements are correct?

A is the reactant in excess. B is the limiting reactant.

Which of the following chemical species, all containing halogen elements, are likely to exist?

AlCl3 NF3

Which of the following properties are associated with the alkali metals? Select all that apply.

Alkali metals are unusually soft. Alkali metals are very reactive.

______ is difficult to classify in any one group of the periodic table because it displays properties of both metals and nonmetals.

Hydrogen

Which of the formulas below, representing compounds of Group 6A elements, are likely to exist?

SO3 H2S Na2Se

Which elements from Groups 13 and 14 can form cations with more than one possible charge? Select all that apply.

Sn Pb In

Oxygen forms many molecular compounds with other nonmetals. As a group, nonmetal oxides tend to be ______.

acidic

The theoretical determination of how much of the starting mass of reactants ends up in the final mass of desired products is known as ___ economy.

atom

The concept of atom economy consists of determining ______.

the mass of reactants that can end up in the desired product, according to the balanced chemical equation.

Although Group 1 and Group 11 elements have similar (ns1) valence electron configurations, their chemical properties are different. Match each group with its correct description. 1. Group 1 2. Group 11

1. Highly reactive; only occur naturally in compounds 2. Higher ionization energies; often found uncombined in nature

Which of the elements below would have similar chemical properties to those of sodium (Na), and which would be most different? Rank the elements in order of their similarity to Na, with the most similar at the top of the list.

1. K 2. Ca 3. Ti 4. Ne

Elements in the same group in the periodic table often have similar chemical reactivity. Which of the following statements is the best explanation for this observation?

Elements in the same group have the same valence electron configuration.