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)