Chemistry SAT II True/False
Covalent bonds must be broken for a liquid to boil BECAUSE heat must be released for a liquid to change into a gas
F F
Hydrogen gas is considered a perfectly ideal gas BECAUSE hydrogen atoms interact with each other via hydrogen bonds
F F
If some phosphoric acid, H₃PO₄, is added to the equilibrium mixture represented by the equation H₃PO₄ + H₂O ↔ PO₄³⁻ + H₃O⁺, the concentration of H₃O⁺ decreases BECAUSE the equilibrium constant of a reaction changes as the concentration of the reactants changes
F F
In an electrochemical cell, the electrode that is the site of reduction is called the anode BECAUSE oxidation always occurs at the cathode
F F
Lithium has a larger first ionization energy than oxygen BECAUSE oxygen atoms have larger atomic radii than lithium atoms
F F
The Cu²⁺ ion needs to be oxidized to form Cu metal BECAUSE oxidation is a gain of electrons
F F
The density of a sample of water is doubled by doubling its mass BECAUSE compared to a gas, the molecules in a liquid are relatively far apart
F F
The weakest of the bonds between molecules are coordinate covalent bonds BECAUSE coordinate covalent bonds represent the weak attractive force of the electrons of one molecule for the positively charged nucleus of another
F F
An atom of ¹²C contains 12 protons BECAUSE the identity of an element is determined by the number of protons in the nuclei of its atoms
F T
An ionic solid is a good conductor of electricity BECAUSE an ionic solid is composed of positive and negative ions joined together in a lattice structure held together by electrostatic forces
F T
At equilibrium, the forward reaction and reverse reaction stop BECAUSE at equilibrium, the reactants and products have reached the equilibrium concentrations
F T
BF₃ has a tetrahedral geometry BECAUSE the central B atom does not have a complete stable octet
F T
Decreasing the atmospheric pressure on a pot of boiling water causes the water to stop boiling BECAUSE changes in pressure are directly related to the boiling point of water
F T
Exothermic reactions absorb heat BECAUSE breaking covalent bonds always requires energy
F T
For an element with an atomic number of 17, the most probable oxidation number is +1 BECAUSE the outer level of the halogen family has a tendency to add one electron to itself
F T
If an acid is added to pure water it increases the water's pH BECAUSE adding an acid to water raises the hydrogen ion concentration in the water
F T
Lithium is the most active metal in the first group of the periodic table BECAUSE lithium has only electron in the outer level
F T
The addition of a catalyst will decrease the ∆H for a reaction BECAUSE a catalyst provides an alternate reaction pathway with a lower activation energy
F T
The anions migrate to the cathode in an electrolytic cell BECAUSE positively charged ions are attracted to the negatively charged cathode
F T
The electrolysis of potassium iodide, KI, produces electrical energy BECAUSE electrons flow from the anode to the cathode
F T
The solubility of gases in liquids does not depend upon pressure BECAUSE the vapor pressure of a substance is independent of external pressure
F T
Two isotopes of the same element have the same mass number BECAUSE isotopes have the same number of protons
F T
When a chlorine atom gains an electron, it becomes a positively charged ion BECAUSE a neutral atom has equal numbers of protons and electrons
F T
the reaction of barium chloride and sodium sulfate does not go to completion BECAUSE the compound barium sulfate is formed as an insoluble precipitate
F T
Alpha particles can be detected using a Geiger counter BECAUSE all radioactive elements are highly chemically reactive
T F
By mass, oxygen is the most abundant element in the human body BECAUSE it is principally found as O₂ in the bloodstream
T F
Chemical reactions slow down with lower temperature BECAUSE the energy barrier for the formation of products decreases with decreasing temperature
T F
Hydrofluoric acid, HF (aq), is a weaker electrolyte than hydrochloric acid, HCl (aq) BECAUSE fluorine has a lower electronegativity than chlorine
T F
In a reaction that has both a forward and a reverse reaction, A+B⇌AB, when only A and B are introduced into a reacting vessel, the forward reaction rate is highest at the beginning and begins to decrease from that point until equilibrium is reached BECAUSE the reverse reaction does not begin until equilibrium is reached
T F
Saltwater boils at a higher temperature than pure water BECAUSE the presence of salt increases the vapor pressure of water
T F
The structure of SO₃ is shown by using more than one structural formula BECAUSE SO₃ is very unstable and resonates between these negative possible structures
T F
The transmutation decay of ²³⁸₉₂U can be shown as ²³⁸₉₂U-->²³⁴₉₀Th + ⁴₂He BECAUSE the transmutation of ²³⁸₉₂U is accompanied by the release of a beta particle
T F
Water boils at a lower temperature at high altitude than at low altitude BECAUSE the vapor pressure of water is lower at higher altitude
T F
When a solute is added to pure water, the vapor pressure of the water will decrease BECAUSE all solutes dissociate into positive and negative ions
T F
When the temperature of a reaction at equilibrium is increased, the equilibrium will shift to favor the endothermic direction BECAUSE at equilibrium, all reactants have been converted into products
T F
When the ∆G of a reaction at a given temperature is negative, the reaction occurs spontaneously BECAUSE when ∆G is negative, ∆H is also negative
T F
when HCl gas and NH₃ gas come into contact, a white smoke forms BECAUSE NH₃ and HCl react to form a white solid, ammonium chlorate
T F
At 25°C, an aqueous solution with a pH of 5 will have a pH of 9 BECAUSE the pH of a buffered solution is not greatly affected by the addition of a relatively small amount of acid or base
T T
Atoms of different elements can have the same mass number BECAUSE the atoms of each element have a characteristic number of protons in the nucleus
T T
Calcium acts as a reducing agent when it reacts with bromine BECAUSE mass is conserved in a chemical reaction
T T
Carbon is a nonmetal BECAUSE carbon atoms can bond with each other
T T
Elemental fluorine is more reactive than elemental neon BECAUSE neon has a larger atomic weight than fluorine
T T
Hydrogen peroxide, H₂O₂, is a good oxidizing agent BECAUSE the hydrogen atoms interact with each other via hydrogen bonds
T T
LiOH is considered a strong base BECAUSE it undergoes neutralization reactions with acids
T T
The oxygen atom in a water molecule has a -2 oxidation state BECAUSE water molecules exhibit hydrogen bonding
T T
The pH of a 0.01 molar solution of HCl is 2 BECAUSE dilute HCl dissociates into two essentially ionic particles
T T
The rate of a reaction is accelerated by increasing temperature BECAUSE a large equilibrium constant favors the formation of product
T T
The reaction of hydrogen with oxygen to form water is an exothermic reaction BECAUSE water molecules have polar covalent bonds
T T
The water molecule is polar BECAUSE the radius of an oxygen atom is greater than that of a hydrogen atom
T T
A nonpolar molecule can have polar bonds BECAUSE polar bonds can be symmetrically arranged in a molecule so that there are no net poles
T T CE
A saturated solution is not necessarily concentrated BECAUSE dilute and concentrated are terms that relate only to the relative amount of solute dissolved in the solvent
T T CE
Ammonia is a Lewis base BECAUSE ammonia can donate an electron pair to a bond
T T CE
An endothermic reaction can be spontaneous BECAUSE both enthalpy and entropy changes affect the value of a reaction's Gibbs free energy change
T T CE
As ice absorbs heat and begins to melt, its temperature remains constant BECAUSE the absorbed heat is consumed by the breaking of intermolecular interactions
T T CE
Carbon-13 and Carbon-14 are isotopes of the same element BECAUSE isotopes of an element have the same number of protons in the nucleus but have a different number of neutrons
T T CE
Crystals of sodium chloride go into solution in water as ions BECAUSE the sodium ion has a 1+ charge and the chloride ion has a 1- charge and they are hydrated by the water molecules
T T CE
Electrolysis of water requires the input of energy BECAUSE the products formed, H₂ and O₂, possess more chemical potential energy than H₂O
T T CE
Elemental sodium is a strong reducing agent BECAUSE an atom of elemental sodium gives up its valence electron readily
T T CE
Hydrosulfuric acid is often used in qualitative tests BECAUSE H₂S (aq) reacts with many metallic ions to give colored precipitates
T T CE
Isotopes of a particular element have nearly identical chemical behavior BECAUSE they have identical electron configurations
T T CE
MgO has a high melting point BECAUSE highly charged ions result in strong ionic forces and high lattice energies
T T CE
Nonmetallic oxides are usually acid anhydrides BECAUSE nonmetallic oxides form acids when placed in water
T T CE
Nuclear fusion on the sun converts hydrogen to helium with a release of energy BECAUSE some mass is converted to energy in a solar fusion
T T CE
One mole of CO₂ has a greater mass than 1 mole of H₂O BECAUSE the molecular mass of CO₂ is greater than the molecular mass of H₂O
T T CE
Oxidation and reduction occur together BECAUSE in redox reactions, electrons must be gained and lost
T T CE
Potassium chloride dissolves readily in water BECAUSE water is a polar solvent
T T CE
Sodium and cesium exhibit similar chemical properties BECAUSE their atoms have the same number of valence electrons
T T CE
The 4s orbitals fills before the 3d orbitals BECAUSE subshells fill in the order from lower to higher energy
T T CE
The addition of acid to a solution buffered to pH slightly lowers the pH BECAUSE the addition of acids to any neutral solution always lowers the pH
T T CE
The atomic number of a neutral atom that has a mass of 39 and has 19 electrons is 19 BECAUSE the number of protons in a neutral atom is equal to the number of electrons
T T CE
The bond in an O₂ molecule is nonpolar BECAUSE the oxygen atoms in an O₂ molecule share the bonding electrons equally
T T CE
The ground state electron configuration orbitals of elemental Cu is [Ar]4s¹3d¹⁰ BECAUSE completely half filled and filled d bestow special electronic stablization
T T CE
The hydrid orbital form of carbon in acetylene is believed to be the sp form BECAUSE C₂H₂ is a linear compound with a triple bond between the carbons
T T CE
The ion of a nonmetallic atom is larger in radius than the atom BECAUSE when a nonmetallic ion is formed, it gains electrons in the outer orbital and thus increases the size of the electron cloud around the nucleus
T T CE
The volume of a gas at 373 K and a pressure of 600 mm of mercury will be decreased at STP BECAUSE decreasing the temperature and increasing the pressure will cause the volume to decrease
T T CE
The ∆Hreaction of a particular reaction can be arrived at by the summation of the ∆Hreaction values of two or more reactions that, added together, give the ∆Hreaction of the particular reaction BECAUSE Hess's Law conforms to the First Law of Thermodynamics, which states that the total energy of the universe is a constant
T T CE
Transition metals compounds are often colored BECAUSE they frequently possess partially filled d orbitals
T T CE
When a salt sample dissolves in water, S for the process is positive BECAUSE for a salt sample, aqueous ions have greater entropy than ions in a solid
T T CE
When a sample of water freezes, the process is exothermic BECAUSE ice is at a lower potential energy state than water
T T CE
When two elements react exothermically to form a compound, the compound should be relatively stable BECAUSE the release of energy from a combination reaction indicates that the compound formed is at a lower energy level than the reactants and thus relatively stable
T T CE
