Chemistry exam
extensive property
An ___________ is a property that depends on the amount of matter present. Examples of extensive physical properties include mass, volume, weight, amount, and length.
intensive property
An _____________ is a property of matter that depends only on the type of matter in a sample and not on the amount. The electrical conductivity of a substance is a property that depends only on the type of substance. Other _______________ include electrical conductivity, flammability, color, temperature, density, and solubility.
22
Argon (Ar) has an atomic number of 18 and a mass number of 40. How many neutrons does argon have in the nucleus?
Liquefaction
As the temperature of the gas decreases and the pressure increases, which phase change occurs?
50 K
At which temperature will nitrogen gas, N2, deviate the most from ideal gas behavior?
0.011 kg
How many kilograms of gold are in a jewelry item that has a mass of 15 g and is made of 75% gold by mass? Use the appropriate number of significant figures.
0.049 mol
How many moles are in 4.1 g of baking soda (NaHCO3)?
2.53 mol
How many moles are in 92.4 g of hydrogen chloride (HCl)?
20. mol
How many moles of CO2 are formed in the following balanced, combustion reaction involving an excess amount of ethane (C2H6) reacting with 35 moles of O2? 2C2H6 + 7O2 → 4CO2 + 6H2O
39.8 mol
How many moles of methane gas (CH4) are present in 892 L of gas at STP (273 K and 1.00 atm)?
15% KCl
If 35 grams of KCl are dissolved in 200.0 g of water to make a solution, what is the percentage by mass of KCl in the solution?
gas state
If the particles of a substance have enough energy to completely overcome intermolecular interactions, then the particles can separate from each other and move about randomly in space. This describes the _________. __________ have the following characteristics: no definite shape no definite volume particles are separated and move randomly in the space
liquid state
If the particles of a substance have enough energy to partially overcome intermolecular interactions, then the particles can move about each other while remaining in contact. This describes the _________. In a liquid, the particles are still in close contact, so liquids have a definite volume. However, because the particles can move about each other rather freely, a liquid has no definite shape and takes the shape dictated by its container.____________ have the following characteristics: no definite shape (takes the shape of its container) definite volume particles are free to move over each other but are still attracted to each other
0.002503 km
If the sides of a triangle measure 102.0 cm, 12.47 cm, and 135.821 cm, what is the distance around the outside of the triangle in kilometers? Use the appropriate number of significant figures.
2.9 mol
If there are 5.7 moles of hydrogen atoms in a sample of water (H2O), how many moles of oxygen atoms are present in the same sample?
decomposition reaction
In a ___________, a single compound will break down to form two or more new substances. The substances that are formed can be elements or compounds. Example: Cu2S (s) → 2Cu (s) + S (s) CaCO3 (s) → CaO (s) + CO2 (g)
solid state
In the ___________, the individual particles of a substance are in fixed positions with respect to each other because there is not enough energy to overcome the attraction between the particles. As a result, solids have a definite shape and volume. ________________ are defined by the following characteristics: definite shape (rigid) definite volume particles vibrate in a fixed position
Synthesis (Combination)
In the following balanced chemical equation, two units of aluminum react with three units of bromine to yield two units of aluminum bromide. 2Al + 3Br2 → 2AlBr3 Which type of reaction does this equation represent?
Combination (Synthesis)
In the following balanced chemical equation, two units of solid sodium react with one unit of fluorine gas to yield two units of solid sodium fluoride. 2Na(s) + F2(g) → 2NaF(s) Which type of reaction does this represent?
225 K
Given: R = 0.08205 L⋅atmmol⋅K�⋅������⋅� What is the temperature, in kelvins, for 50.2 g of N2 gas in a 20.0 L tank with a pressure of 1.65 atm ?
uniform pure substances and mixtures.
matter can be classified into two broad categories:
180°
Carbon dioxide (CO2) has a linear structure. What is the angle between C-O bonds in CO2?
35.45 amu
Chlorine (Cl) has two naturally occurring isotopes: chlorine-35 at 75.77% with an atomic mass of 34.969 amu and chlorine-37 at 24.23% with an atomic mass of 36.966 amu. What is the average atomic mass of chlorine? Use the appropriate number of significant figures.
7.0 mol
Given a sodium ion (Na+) concentration of 3.5 molar, how many moles of NaCl will present in 2.0 L of solution?
375 cm
Given: 1 ft = 12 in and 1 in = 2.54 cm If the length of an iron bar is 12.3 ft, what would this measurement be in centimeters?
8.37 atm
Given: R = 0.08205 L⋅atmmol⋅K�⋅������⋅� What is the pressure of 61.5 moles of O2 gas in a 175 L tank at 17.0°C?
-2
What is the expected charge of monoatomic ions made from elements in group 16?
PCl5; covalent
What is the formula and type of bond for the compound phosphorus pentachloride?
5.6 M
What is the molar concentration of a solution made by dissolving 2.5 moles of KCl in enough water to produce 450 mL of solution?
pH = 8.0, base
What is the pH of a solution that has [H3O+] = 1 × 10-8 M, and is it an acid or a base?
Solid
What is the physical state of a substance that has a definite shape and volume?
They are inversely related.
What is the relationship between atomic radius and electron affinity?
They are directly related.
What is the relationship between the ionization energy and the atomic numbers for elements in period 2?
10%
What is the volume percentage of rose extract in a solution prepared by dissolving 20 mL of rose extract in a solvent to make a 200 mL solution?
107 g
When an aqueous solution of silver nitrate reacts with an aqueous solution of calcium chloride, a solid silver chloride precipitate is formed along with aqueous calcium nitrate, as shown in the balanced chemical equation that follows. 2AgNO3(aq) + CaCl2(aq) → 2AgCl(s) + Ca(NO3)2(aq) How many grams of solid silver chloride can be produced from 2.50 L of 0.300 M silver nitrate and excess calcium chloride? Compound Formulas with Molar Masses Compound Formula Molar Mass (g/mol) Calcium chloride CaCl2 110.98 Calcium nitrate Ca(NO3)2 164.10 Silver chloride AgCl 143.32 Silver nitrate AgNO3 169.88
2Ag2O→4Ag+O2
Which chemical equation correctly represents the decomposition of silver oxide to form silver and oxygen?
TiCl4(aq)+2Mg(l)→Ti(s)+2MgCl2(aq)
Which chemical equation correctly represents the reaction between aqueous titanium(IV) chloride and liquid magnesium to produce solid titanium and aqueous magnesium chloride?
3CaCl2+2Na3PO4→6NaCl+Ca3(PO4)2
Which chemical equation correctly represents the reaction between calcium chloride and sodium phosphate to form sodium chloride and calcium phosphate?
3PCl5+5AsF3→3PF5+5AsCl3
Which chemical equation represents the reaction between phosphorus pentachloride and arsenic trifluoride to produce phosphorus pentafluoride and arsenic trichloride?
2000 atm and 73.15 K
Which conditions would be the most suitable for the liquefaction of air?
Elements combine to form a new compound.
Which description correctly characterizes a synthesis reaction?
V = nRT/P
Which equation should be used to find the volume of an ideal gas if n, P, and T are given?
Kc=[CH3OH][H2]2[CO]
Which equilibrium constant's expression represents the following balanced chemical equation?2H2(g)+CO(g)⇌CH3OH(g)
Kc=[NO]2[Cl2][NOCl]2
Which equilibrium constant's expression represents the following balanced chemical equation?2NOCl(g)⇌2NO(g)+Cl2(g)
Kc=[I−3][I2][I−]
Which equilibrium constant's expression represents the following balanced chemical equation?I2(aq)+I−(aq)⇌I−3(aq)
Tetrahedral
Which geometry has an angle of 109.5° between electron groups?
Radon
Which period 6 element is a nonmetal?
Immiscible
Which term describes the solubility of a nonpolar covalent compound, such as hexane, in water?
Immiscible
Which term describes the solubility of a nonpolar substance, such as gasoline, in water?
Isotopes
Which term is used to describe atoms that have the same atomic number but different mass numbers because of varying numbers of neutrons?
Direct relationship
Which type of relationship is present between these characteristics?
significant
Zeros between nonzero digits are __________. 1305.6 has five significant figures.
0.010 mol
Zinc (Zn) and 20.0 mL of 1.0 M hydrochloric acid (HCl) were allowed to react to yield zinc chloride (ZnCl2) and hydrogen gas as shown in the following balanced chemical reaction. Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g) Based on this information, what is the maximum number of moles of ZnCl2 that can be produced?
2.54
1 in = _______ cm
synthesis reaction
A ________ is also known as a combination reaction. In this kind of reaction, elements or compounds combine to form a single new substance. Example: 2Na (s) + Cl2 (g) → 2NaCl (s)
heterogeneous mixture
A _________ is a mixture in which the composition is not uniform throughout the mixture. Vegetable soup is a __________. Any given spoonful of soup will contain varying amounts of the different vegetables and other components of the soup. ___________ have two or more phases as they do not have uniform composition. For example, oil and water do not mix well and separate into two phases.
pure substance
A ___________ is a form of matter that has a constant composition (meaning that it is the same everywhere) and properties that are constant throughout the sample. Pure substances can either be elements or compounds. Aluminum, from which soda cans are made, is an example of a pure substance that is also considered an element.
homogeneous mixture
A ___________ is a mixture whose composition is uniform throughout the mixture. In the ____________ of salt water, the amount of salt in the salt water can vary from one sample to another. __________ exist in a single phase or layer as they have uniform composition throughout. Salt water will have a single phase.
single-replacement reaction
A ___________ is also known as a single-displacement reaction. an element and a compound will react so that their elements are switched. This means that an element will typically displace another element from within a compound. An important rule in single-replacement reactions is that metals will replace metals in compounds, and nonmetals will typically replace nonmetals. Example: Zn (s) + CuCl2 (s) → ZnCl2 (s) + Cu (s)
double-replacement reaction
A ____________ can also be known as a double-displacement reaction. two ionic compounds in aqueous solution switch anions and form two new compounds. There are two equivalent ways of considering a double-replacement equation: either the cations are swapped or the anions are swapped. Example: BaCl2 (aq) + Na2SO4 (aq) → BaSO4 (s) + 2NaCl (aq)
precipitation reaction
A _____________ occurs when two ionic compounds are dissolved in water and form a new ionic compound that does not dissolve. This new compound will fall out of solution as a solid precipitate.
Homogeneous mixture
A beverage is made by mixing sugar, water, and freshly squeezed lemon juice without pulp.What is the category of matter of the beverage?
Intensive and physical
A container of lip balm was left in an automobile on a hot summer day which caused it to melt. Which properties accurately describe the melting of lip balm?
Supersaturated
A hot saturated solution is slowly cooled to room temperature so that all the solute remains in the solution, exceeding the solute's maximum solubility limit at room temperature. Which term best describes the solution formed?
Physical change
A person is driving an automobile when a rock hits the windshield and shatters the glass. Which change occurred when the glass was broken?
pH = 9.11, base
A substance has a hydroxide ion (OH-) concentration of 1.3 × 10-5 M. What is its pH, and is it an acid or a base?
pH = 8.17, base
A substance is dissolved in water at 25°C and is determined to have a hydronium ion (H3O1+) ion concentration of 6.7 × 10-9 M. What is the pH of the substance, and is it an acid or a base?
compound
A substance made up of two or more different elements chemically bonded together is called a ____________. Compounds are pure substances as they have uniform and definite composition. An example of a compound would be ordinary (non-iodized) table salt, also called sodium chloride.
nonzero
All ________ digits are significant. 1572 has four significant figures.
It is more concentrated.
Beaker A contains 10 mg of calcium chloride dissolved in 100 mL of ethanol, and beaker B contains 8 mg of calcium chloride dissolved in 100 mL of ethanol. When compared to beaker B, which statement best describes the solution in beaker A?
79.90 amu
Bromine (Br) has two naturally occurring isotopes: bromine-79 at 50.69% with an atomic mass of 78.918 amu, and bromine-81 at 49.31% with an atomic mass of 80.916 amu. What is the average atomic mass of bromine? Use the appropriate number of significant figures.
Intensive and physical
Fibers collected at crime scenes have electrical conductivity testing performed on them if they are suspected of containing metal. Which properties correctly describe the electrical conductivity of these fibers?
The concentration of the reactants will increase, while the concentration of the products will decrease.
In the following formula, one unit of nitrogen (N2) and one unit of oxygen (O2) react to form two units of nitrous oxide (NO) in an exothermic reaction. N2(g)+O2(g)⇌2NO(g)+ heat N2(g)+O2(g)⇌2NO(g)+ heat If the temperature of the system is increased, what will happen to the concentrations of the products and the reactants when the system reestablishes its equilibrium?
39%
In the following reaction, 3.4 g of ammonia (NH3) is mixed with 2.1 g of hydrochloric acid (HCl) to produce 1.2 g of ammonium chloride (NH4Cl).NH3+HCl→NH4ClNH3+HCl→NH4ClWhat is the percent yield of ammonium chloride (NH4Cl)? CompoundMolar Mass (g/mole) NH3 17.0304 HCl 36.4608 NH4Cl 53.4912
Limiting reactant: N2; theoretical yield: 9.8 g of NH3
In the following reaction, 8.1 g of nitrogen (N2) is mixed with 4.5 g of (H2) to produce ammonia (NH3).N2+3H2→2NH3N2+3H2→2NH3What are the limiting reactant and the theoretical yield, in grams, of ammonia (NH3)? CompoundMolar Mass (g/mole) N2 28.014 H2 2.0156 NH3 17.0304
Liquid
Mercury has a freezing point of −39°C and a boiling point of 356.73°C. Which state will mercury be in at 0°C?
Limiting reactant: Br2; theoretical yield: 39.7 g of PBr3
Mistake 36. In the following reaction, 35.2 g of bromine (Br2) is mixed with 23.1 g of phosphorus (P) to produce phosphorus tribromide (PBr3). 3Br2+2P→2PBr33Br2+2P→2PBr3What are the limiting reactant and the theoretical yield, in grams, of phosphorus tribromide? CompoundMolar Mass (g/mole) Br 2159.808 P 30.974 PBr3 270.686
91.20 amu
Naturally occurring zirconium (Zr) is composed of 51.45% of zirconium-90 (89.905 amu), 11.22% of zirconium-91 (90.906 amu), 17.15% of zirconium-92 (91.905 amu), 17.38% of zirconium-94 (93.906 amu), and 2.800% of zirconium-96 (94.908 amu). What is the average atomic mass of zirconium? Use the appropriate number of significant figures.
covalent bonds
Nonmetal atoms frequently form __________ with other nonmetal atoms. Two atoms can share one, two, or three pairs of electrons to make a single, a double, or a triple covalent bond.
crystal lattice
Solids, if ionic, usually have their constituent particles arranged in a regular, three-dimensional array of alternating positive and negative ions called a ________. A ___________ is an arrangement or pattern of atoms or molecules.
mass number
The ________ of an element is defined as the total number of protons and neutrons in the nucleus of an atom. Mass number = atomic number + number of neutrons
atomic mass
The ___________ is the number of protons plus the number of neutrons.
atomic number
The _____________ (Z) of an element determines the number of protons the element has in its nucleus.
The concentration of the products will increase.
The following endothermic reaction is at equilibrium. NH4HS(s)⇌NH3(g)+H2S(g)NH4HS(s)⇌NH3(g)+H2S(g) What will happen if the temperature is increased when the system is at equilibrium?
The concentration of the reactants will decrease, while the concentration of the products will increase.
The given chemical reaction reaches equilibrium.O2(g)+2H2(g)⇌2H2O(g)+ heat O2(g)+2H2(g)⇌2H2O(g)+ heat How is the chemical equilibrium affected when the temperature decreases?
nucleus
The mass of an atom comes from its ____.
decimal point
Trailing zeros are significant if the ___________ is present. Example: 1570. has four significant figures because the decimal point is present.
1 amu
What is the atomic mass unit (amu) of a proton?
Na2CO3
What is the correct formula for sodium carbonate? Use the following table as needed:
Hecto
_______ = 100
Cations
_______ are positively charged ions
anions
________ are negatively charged ions.
protons
________, which have a positive electric charge
Trailing zeros
_________ (those after the whole numbers but not between them) are not significant if there is no decimal point present. Example: 1570 has three significant figures because there is no decimal point.
Ionic bonds
_________ are bonds that occur between a metal and nonmetal. Usually, metal atoms in ionic bonds lose electrons to become cations, and nonmetal atoms gain electrons to become anions.
Centi
__________ = .01
neutrons
__________, which are neutral in electric charge
electrons
__________, which have a negative electric charge
tetrahedral geometry
__________: a molecular structure in which four-electron groups are farthest apart, with the central atom at the center of a tetrahedron and bond angles of 109.5° around the central atom
trigonal planar geometry
__________: a molecular structure in which three-electron groups are farthest apart, with the central atom in the middle of a triangle and bond angles of 120° around the central atom
linear geometry
__________: a molecular structure in which two-electron groups are farthest apart, with the central atom in the middle of a line and bond angles of 180° around the central atom
Nano
___________ = .000000001
MIlli
___________ = .001
Deci
___________ = .1
Physical changes
___________ are changes in which no bonds are broken or formed. This means that the same types of compounds or elements that were there at the beginning of the change are there at the end of the change. Types of __________ include the following: change of state (changes from a solid to a liquid or a gas and vice versa) separation of a mixture deformation (cutting, denting, stretching) formation of solutions, which are special kinds of mixtures
Leading zeros
____________ (zeros before the first whole number) are not significant. 0.0134 has three significant figures.
Deka
____________ = 10
Micro
_____________ = .000001