Chemical Reactions
Which type of reaction below represents an acid-base reaction? 3 HBr + Al(OH)3 → 3 H2O + AlBr3 2 NaBr + Ca(OH)2 → CaBr2 + 2 NaOH MgCl2 + Li2CO3 → MgCO3 + 2 LiCl 2 NH3 + H2SO4 → (NH4)2SO4
3 HBr + Al(OH)3 →3 H2O + AlBr3 An acid-base reaction occurs when an acid and a base react with one another to form water and a salt. In 3 HBr + Al(OH)3 → 3 H2O + AlBr3 HBr is the acid, Al(OH)3 is the base, and AlBr3 is the salt. Although it looks similar, 2 NaBr + Ca(OH)2 → CaBr2 + 2 NaOH is a double displacement reaction.
Which of the following electron sub-shells would participate in bonding with Na? 1s 3s 2s 2p
3s Only an atom's valence electrons participate in bonding. Sodium (Na) is in the s-block of elements and it is in the 3rd period. So, only the 3s electrons of sodium will participate in bonds. Thus, even though the electron configuration of sodium includes electrons in the 1s, 2s, and 2p subshells, they are part of the core electrons and do not generally participate in reactions.
When methane (CH4) is heated in the presence of oxygen, water and CO2 are produced. What type of reaction is this? Combustion Decomposition Double replacement Synthesis
Combustion Combustion occurs when a chemical (a hydrocarbon) is heated in the presence of oxygen. The products of this reaction are always carbon dioxide (CO2) and water (H2O).
Which of the following describes an ion? A charged atom An atom with a full octet of valence electrons A neutral atom A radioactive atom
charged atom Ions are atoms that have either gained or lost electrons, which gives them a negative or positive charge, respectively. A positively - charged ion is a cation, and a negatively - charged ion is an anion. Ions are very reactive because they want to gain or lose electrons to return to a neutral state.
Which of the following shows a synthesis reaction? AB → A + B AB → A+ + B- AB + DC → AD + BC A + B → AB
A + B → AB In a synthesis reaction, two different chemicals are combined into a product. The opposite of this reaction is a decomposition reaction, where a chemical breaks apart. Synthesis is the most important type of chemical reaction and is used to make a variety of chemicals.
Which of the following describes a single covalent bond? A bond that shares one electron pair A bond that shares two electron pairs A bond that shares a single proton A bond that shares no electron pairs
A bond that shares one electron pair In covalent bonds, electrons are shared between two atoms. This differs from ionic bonds, where electrons are completely donated from one atom to another. In a single covalent bond, one electron pair is shared, while in a double covalent bond, two electron pairs are shared.
Which of the following is used to predict the products of a displacement reaction? Activity series Ionic exchange rules Solubility rules Displacement predictions
Activity series The activity series (or reactivity series) is a set of rules that can be used to predict whether a displacement reaction will occur or not.
What atom property determines if a bond is polar or non-polar? Electron affinity Electronegativity Polarity Ionization energy
Electronegativity The electronegativity of an atom is its ability to attract electrons to itself. If two atoms have the same electronegativity, the bond will be non-polar. If two atoms have very different electronegativities, the bond will be polar.
Which of the following is not an intermolecular force? Dipole-dipole interaction Dispersion force Hydrogen bond Metallic bond
Metallic bond Metallic bonds hold metal lattices together and are an intramolecular force. Other examples of intramolecular forces are covalent bonds and ionic bonds. The other options are intermolecular forces that determine how other molecules interact with one another.
What type of bonding exists in NaCl? Isotopic Stoic Synthetic Ionic
Ionic NaCl is an ionic compound, which consists of a metal (Na) and a nonmetal (Cl). In this type of compound, ionic bonds are formed between the two atoms where the metal completely donates its electrons to the nonmetal.
Which of the following represents the general form of a decomposition reaction? AB + CD → AD + BC A + O2 → H2O + CO2 AB + C → AC + B AB → A + B
AB → A + B A decomposition reaction occurs when a compound breaks apart to form its constituent atoms. It looks like this: AB → A + B A combustion reaction occurs when fuel and oxygen yield water and carbon dioxide. A + O2 → H2O + CO2 A single replacement reaction occurs when one element replaces another in a single compound. AB + C → AC + B A double replacement reaction (also called a metathesis reaction) occurs when the cations and anions switch between two reactants to form new products. AB + CD → AD + BC
Which of the following shows a double displacement reaction? AgNO3 + NaCl → AgCl + NaNO3 Fe + Pb(NO3)2 → Pb + Fe(NO3)2 Fe + CuSO4 → Cu + FeSO4 CH4 + 2O2 → 2H2O + CO2
AgNO3 + NaCl → AgCl + NaNO3 A double displacement reaction occurs when two different ions swap places with each other in two different ionic compounds. This creates two new ionic compounds. In the example above, Ag and Na have swapped places with (displaced) each other.
Which of the following describes a non-polar covalent bond? An even sharing of electrons between atoms An even sharing of protons between atoms An uneven sharing of electrons between atoms An uneven sharing of protons between atoms
An even sharing of electrons between atoms In a non-polar covalent bond, electrons are shared evenly between the atoms in the molecule. This means that the overall molecule does not have a dipole. In a polar covalent bond, electrons are shared unevenly between atoms because one atom is more electronegative than the other.
Which of the following describes a decomposition reaction? Chemicals are broken apart to form products Chemicals combine to form products Chemicals are burned in oxygen Chemicals switch ions
Chemicals are broken apart to form products In a decomposition reaction, the reactants are broken down into their constituent parts. A synthesis reaction occurs when chemicals combine with each other. A combustion reaction occurs when chemicals are burned in oxygen. A displacement reaction occurs when ions switch places with one another.
Which of the following is a positively-charged atom? Protons Ion Cation Anion
Cation A cation is a positively-charged ion. In ionic compounds, cations combine with negatively-charged anions to form the compound. Protons, while positively-charged, are a subatomic particle and are not an atom or ion.
Which of the following comprise an ionic compound? Cation and anion Electron and quark Cation and proton Anion and neutron
Cation and anion An ionic compound is composed of a metal and a nonmetal. The metal is typically the cation and is positively-charged. The non-metal is typically the anion and is negatively-charged. A common example of an ionic compound is table salt, sodium chloride (NaCl).
What kind of bond would hold carbon and hydrogen together? Metallic bond Covalent bond Ionic bond Hydrogen bond
Covalent bond Although you might be tempted to say hydrogen bond for this answer, remember that hydrogen bonds are intermolecular forces and don't hold molecules together. Covalent bonds are formed when electrons are shared between two atoms, like hydrogen and carbon. Although hydrogen and carbon are on opposite sides of the periodic table, hydrogen generally behaves as a nonmetal, like carbon.
Which of the following is an intramolecular force? Covalent bonds Hydrogen bonding Dipole-dipole interactions Dispersion forces
Covalent bonds Intramolecular forces hold different atoms together in a molecule. Intramolecular forces are much stronger than intermolecular forces, which are attractions between different molecules. Ionic bonds, covalent bonds, and metallic bonds are all intramolecular forces. Hydrogen bonds are a type of intermolecular force, where the hydrogen atom is bonded to an electromagnetic atom (such as oxygen) of a different molecule. The illustration below is a visual reference for covalent bonds.
Which of the following molecules will have hydrogen bonding? BF3 C6H6 CH4
HCl
Which intermolecular force is the strongest? Hydrogen bonds Dispersion forces Dipole-dipole interactions Ionic bonds
Hydrogen bonds Intermolecular forces are interactions that occur between molecules in proximity to one another. Hydrogen bonds occur when hydrogen is bonded to an incredibly electronegative atom, such as oxygen or chlorine, from a neighboring molecule. The diagram below is a visual reference for hydrogen bonds.
Which of the following types of chemicals participates in a double replacement reaction? Elements Ionic compounds Diatomic molecules Molecular compounds
Ionic compounds A double replacement reaction is represented by the general reaction diagram AB + CD → AC + BD. The reactants are two ionic compounds, and two different ions switch places with each other to form two new ionic compounds in the products. Elemental metals can participate in single replacement reactions.
Which is the strongest intramolecular force? Nonpolar covalent bond Ionic bonding Polar covalent bond Metallic bonding
Metallic bonding Metallic bonding occurs between metal atoms. In this type of bonding, the valence electrons of metals are delocalized and can move about the metal lattice. Metallic bonds exist in pure metals, like gold.
What is another term for a displacement reaction? Combustion Decomposition Metathesis Synthesis
Metathesis A displacement reaction occurs when one or more ions switch places with one another in ionic compounds. Metathesis reactions are used to exploit the different water solubilities of salts in order to precipitate desired compounds.
Which of the following has an ionic bond? H2O H2O2 NaCl C6H12O6
NaCl NaCl is an ionic compound because it is composed of a metal (Na) and a nonmetal (Cl). In an ionic bond, electrons are completely transferred from the metal to the nonmetal. The other answer choices are all molecular compounds. Below is an illustration of an ionic bond.
Which of the following is the correct formula for sodium chloride? SrCl2 SnCl SbCl NaCl
NaCl Sodium chloride (NaCl) is just table salt. It is an ionic compound comprised of one sodium atom and one chlorine atom, where Na+ is the cation and Cl- is the anion. The atoms in the other options are seaborgium (Sb), tin (Sn), and strontium (Sr).
Which of the following is not likely to have a dipole? Ionic compound Polar compound Salt Nonpolar compound
Nonpolar compound A dipole occurs when there is an unequal sharing of electrons between two atoms in a molecule. In the dipole, there will be both a partially - positive and a partially-negative side. The more electronegative atom will be on the partially-negative side since it will be able to attract more electrons to itself.
What type of bond is formed when a bond's electrons are equally shared? Polar covalent bond Ionic bond Hydrogen bond Nonpolar covalent bond
Nonpolar covalent bond In covalent bonds, electrons are shared between the two atoms that participate in the bond. In a polar covalent bond, the electrons are shared unequally, with more electrons being centered around the more electronegative element. In a non-polar bond, electrons are shared equally.
Which of the following is the correct term for chemicals on the left side of the reaction arrow? Products Ions Equation Reactants
Reactants The reactants are the chemical species that are used to generate the products. Reactants are always on the left side of the reaction arrow, and products are always on the right side.
In a chemical equation, what do (aq), (l), (g), and (s) represent? Solubility of reactants Products States of matter Reactants
States of matter The information in parenthesis next to reactants and products in a chemical equation represent the state of matter that the chemical exists in during the reaction. Chemicals can be present as a liquid (l), solid (s), or gas (g). They can also be aqueous (aq), which means that the chemical is ionized in water during the reaction.
What type of reaction is shown below: 2C5H5 + Fe → Fe(C5H5)2 Double displacement Decomposition Synthesis Single displacement
Synthesis Although it may look like a single displacement reaction at first, the reaction above is a synthesis reaction since two different reactants combine into a single product.
What does a double arrow mean in a chemical reaction? The reaction does not proceed The reaction is reversible A combustion reaction has occurred The reaction proceeds to completion
The reaction is reversible When a double arrow is used in a chemical reaction, this means that both the forward and reverse reaction are occurring. An equilibrium has been established between the forward reaction and the reverse reaction, meaning that both products and reactants are being formed.
What type of electrons participate in chemical bonds? Valence electrons Inner shell electrons Auger electrons Core electrons
Valence electrons Valence electrons occupy the outermost shell of electrons and have the highest energy of an atom's electrons. Core (inner shell) electrons do not participate in bonding.