Chemistry Chapter 12

actual yield < theoretical yield expressed as

% yield

1 mol of any gas is

22.4 L

How many moles of mercury (II) oxide are needed to produce 125 g of oxygen gas?

7.81 mol of HgO are required for the reaction to produce 125 g of O2.

R=

8.31 kPa • L/mol • K

When magnesium burns in air, it combines with oxygen to form magnesium oxide according to the equation 2Mg + O2 → 2 MgO. What mass in grams of magnesium oxide is produced from 2.00 mol of magnesium?

80.6 g of MgO are produced for this reaction.

read notes on empirical formula

:)

for counting many small things use a

large unit of measure

covalent compounds are composed of

molecules

individual gas particles are so small they cannot be be

observed

for counting few or larger things use

small unit of measure

Avogadro's Principle

statement that at the same temperature and pressure, equal volumes of gases contain equal number of particles

actual yield may be affect by

the collection techniques and apparatus used, time, and the skills of the chemist

molar mass

the mass of one mole of a pure substance

sulfuric acid is probably

the single most important industrial chemical in the world

stoichiometry

the study of relationships between measurable quantities, such as mass and volume, and the number of atoms in chemical reactions

balanced chemical equations indicate

the volume of gas required for a reaction or the volume of gas produced

in chemical reactions, when substances react

their particles react

atomic mass unit

u, is defined so that the atomic mass of an atom of the most common car- bon isotope is exactly 12 u

mole

unit of measurement used to count number of atoms, molecules, or formula units of substances

actual yield

usually less than predicted

law of combining volumes

volumes of gases always combine in definite ratios

____ is the source of the conversation factors relating moles of one substance to moles of another substance. A. the balance chemical equation B. the ideal gas law C. the empirical formula D. Avogadro's constant

A. the balance chemical equation

What is the mass percent of each element on NiI₂? A. 33.3% Ni; 66.7% I B. 66.7% Ni; 33.3% I C. 18.8% Ni; 81.2% I D. 81.2% Ni; 18.8 % I

C. 18.8% Ni; 81.2% I

Calculate the formula mass of Ca₃(PO₄)₂. A. 620 grams B. 310 grams C. 310 u D. 620 u

C. 310 u

Which of the following could be an empirical formula? A. C₆H₆ B. N₂O₂ C. CH₂O D. C₄H₁₀

C. CH₂O

What is the formula for a compound with a molecular mass of 695 grams that is made up of 12.1% N, 26.7% P, and 61.2% Cl? A. P₂N₂C₁₄ B. PNC₁₂ C. P₆N₆Cl₁₂ D. P₄N₄C₁₈

C. P₆N₆Cl₁₂

Use the ideal gas law (R = 8.31 kPa L/mol K) to determine how many moles of a gas occupy a 550-mL canister at 11°C and 66.7 kPa pressure. A. 0.00155 mol B. 15.5 mol C. 0.401 mol D. 0.0155 mol

D. 0.0155 mol

How many moles is 146 grams of CaCl₂? A. 0.51 moles B. 1.94 moles C. 0.76 moles D. 1.32 moles

D. 1.32 moles

Convert 0.70 mole benzene, C₆H₆, to grams. A. 111 grams B. 78 grams C. 0.009 grams D. 54 grams

D. 54 grams

Which element in aluminum acetate, Al(C2H3O2)2, has the greatest mass percent of the compound? A. H B. C C. Al D. O

D. O

chemist analyze mixtures to

determine their compositions

the volumes of gases can be measured

directly

In the production of carbon disulfide (CS2), carbon (C) and sulfur dioxide (SO2) are reacted. If 8.00 g of sulfur dioxide reacts, how many moles of carbon dioxide are produced?

0.125 mol of carbon dioxide are produced from this reaction.

Oxygen gas is united with hydrogen gas to form water vapor. How many grams of oxygen are necessary to produce 32.0 grams of water?

28.4 g of oxygen are necessary for this reaction to occur.

In the following reaction, CO2 + 2LiOH → Li2CO3 + H2O, how many moles of lithium hydroxide are required to react with 20 mol of CO2?

40 mol of Lithium Hydroxide are required.

1 mole (Avogadro's constant)=

6.02 x 10²³

When sodium chloride reacts with silver nitrate, silver chloride precipitates. What mass of AgCl is produced from 75.00 g of AgNO3?

63.3 g of AgCl are produced from this reaction.

Determine the volume of ammonia produced by 1.5 L of hydrogen in the following reaction: N₂ (g) + 3H₂ (g) → 2NH₃ (g). A. 1.5 L B. 1 L C. 2.25 L D. 4.5 L

B. 1 L

Find the empirical formula for a compound containing 1.67 grams cerium and 4.54 grams of iodine. A. CeI B. CeI₃ C. CeI₂ D. Ce₃I₃

B. CeI₃

According to Avogadro's principle, at equal temperatures and pressures, equal volumes of gases have equal masses. A. true B. false

B. false

44.0 grams is the ____ for CO₂ A. molecular mass B. molar mass C. atomic mass D. formula mass

B. molar mass

How are actual yield, theoretical yield, and percent yield related? A. actual yield = (theoretical yield / percent yield) x 100 B.percent yield = (actual yield / theoretical yield) x 100 C. theoretical yield = actual yield / percent yield D. percent yield = (theoretical yield / actual yield) x 100

B. percent yield = (actual yield / theoretical yield) x 100

Which of the following is correct about acetone, (CH3)2CO? A. formula mass = 58.1 g B. ionic mass = 58.1 g C. molecular mass = 58.1 g D. molar mass = 58.1 g

D. molar mass = 58.1 g

theoretical yield

The amount of product of a chemical reaction predicted by stoichiometry

Ideal Gas Law

The equation that expresses exactly how pressure P, volume V, temperature T, and the number of particles n of a gas are related PV=nRT

Empirical formula

The formula of a compound having the smallest whole-number ratio of atoms in the compound

Molecular mass of a covalent compound

The mass in atomic mass units of one molecule

Formula mass of an ionic compound

The mass in atomic mass units one formula unit

Find the percentage composition of sucrose, C12H22O11.

The percentage of C12 is 42.1%. The percentage of H22 is 6.4%. The percentage of O11 is 51.5%.

Which are the reactants and which are the products in the following reaction? CO2 + 2LiOH → Li2CO3 + H2O

The reactants are Carbon Dioxide and Lithium Hydroxide. The products are Lithium Carbonate and Water.

Molar volume

The volume that a mole of gas occupies at a pressure of one atmosphere and a temperature of 0.00°C

In the reaction of the previous problem (#5), how many grams of acetylene gas is produced?

This reaction produces 13 g of acetylene gas.

Acetylene gas (C2H2) is produced from calcium carbide (CaC2) and water. Calcium hydroxide is the other product. If 32 grams of calcium carbide are consumed, how many grams of water are needed?

This reaction requires 18 g of water.

percent yield is

actual yield/theoretical yield x 100%

"u" means

atomic mass units

molecular mass/formula mass are in

atomic mass units and they equal molar mass of 1 mol

ionic compounds are composed of

formula units

units of molar mass

grams per mole (g/mol)