NLN NEX Chemistry Practice Test

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• Which law states that energy cannot be created or destroyed, and the total energy in an isolated system remains constant?
• What term describes a reaction where one compound acquires a proton from another?
• Which properties do not depend on the amount of matter or quantity of the sample?
• How many neutrons are present in the isotope Fe-56?
• For an exothermic reaction at equilibrium, if the temperature increases, in which direction does equilibrium shift?
• Atoms of the same element with different numbers of neutrons are called ...
• What type of bonds are created by sharing electrons with other atoms in a molecule?
• Convert 3.5 centimeters to meters.
• Which process involves a change of state from one phase to another, such as melting or freezing?
• A weak acid has Ka ≈ 1.8 × 10^-5. Is it a strong or weak acid?
• If a solid has a density of 2.00 g/mL and a mass of 300 g, what is its volume?
• Which process increases entropy?
• Which type of covalent bond involves two electron pairs and is stronger and shorter than a single bond?
• What type of bond forms between a metal and a nonmetal?
• Extensive properties include which of the following?
• Which property cannot be measured without changing the identity or composition of matter?
• Which quantum number describes the direction of spin of an electron in an orbital?
• Which subatomic particle is located in the nucleus and carries a positive charge?
• What term describes a substance formed when two or more elements are chemically bonded?
• Which type of covalent bond involves two pairs of electrons and is stronger and shorter than a single bond?
• Volume of 0.100 M NaOH required to reach equivalence with 25.0 mL of 0.100 M HCl in a 1:1 reaction.
• Define a buffer solution.
• What term describes a combination of two or more substances that are not chemically combined?
• What is the region in space that indicates the probability of finding an electron at a given location?
• When bases are added to a buffer solution, what typically happens?
• If a strong acid solution has [H+] = 0.005 M, what is its pH?
• Elements consist of only one type of atom and may be
• The number of protons in the nucleus of an atom is called what?
• A solution contains 0.60 mol solute in 3.0 L. What is its molarity?
• A description of the sequence of steps by which a reaction occurs is known as
• In CO2, how many electron domains around the central atom and what is the molecular geometry?
• The characteristics of a substance that can be observed or measured without changing its identity or composition are called what?
• What is the term for a fixed circular or elliptical path associated with a particle's motion?
• Which type of process produces new substances as a result of the reaction?
• What is the basic type of matter that cannot be broken down further?
• Which type of properties describe substances' behavior in chemical reactions?
• A less concentrated or dilute solution indicates which of the following about the amount of solute dissolved?
• The process in which a compound rearranges to form an isomer with the same molecular formula but different structure is called
• Which term describes properties observed or measured without changing the identity?
• Which type of transitions produce spectral lines?
• Which term correctly names properties like color, hardness, melting point, and density?
• For reaction N2 + 3 H2 → 2 NH3, if you start with 1.0 mol N2 and 2.0 mol H2, what is the limiting reagent and how many moles of NH3 can be formed?
• Which statement about strong acids is true?
• Which type of covalent bonds occurs when electrons are shared equally between atoms?
• Which quantum number indicates the shape or type of subshell in which an electron is found?
• Define molar solubility.
• Which properties depend on the amount of matter?
• Which quantum number indicates the main energy level and distance of the orbital from the nucleus?
• Temperature and pressure affect solubility. Which statement is correct?
• Catalysts lower the activation energy, meaning more of the reactant molecules will have sufficient energy to react.
• Which subatomic particle is located in the nucleus and has no electric charge?
• Which process is characterized by the formation of new substances, such as rusting iron?
• In CaF2, what is the charge on the calcium ion?
• If a gas sample's volume doubles while temperature and amount stay constant, what happens to pressure?
• Neutral Atoms have the same number of protons and electrons.
• Identify the conjugate base of HSO4- formed after losing one proton.
• A positively charged particle located in the nucleus is called what?
• In a solution, the substance that is dissolved into the solvent is called the
• Electronegativity is defined as the ability of an atom to attract electrons in a bond; how does it relate to bond polarity?
• A gas sample at STP has a mass of 44.0 g and occupies 11.2 L. What is its molar mass?
• Which bond type is associated with the attraction between metal atoms and a sea of electrons?
• What is the pH of a 0.20 M NaOH solution?
• A buffer solution resists changes in pH when small amounts of acid or base are added. Which statement best describes this property?
• A mixture that is uniform throughout is called
• A dilution by a factor of 4 reduces concentration by what factor?
• The number that defines the identity of the element is the ...
• What is the molecular geometry of methane, CH4?
• What is the pH of a 0.01 M HCl solution?
• A 0.10 M solution is diluted to 0.010 M. What is the dilution factor?
• A heterogeneous mixture in which small particles are suspended but never combined (ex. milk) is known as a
• Polyprotic acids are acids that can donate two or more protons per molecule.
• Which group ionizes essentially completely in an aqueous solution?
• Activation energy is the minimum energy that must be possessed by reactants to react.
• Which process uses electrical energy to decompose compounds into simpler substances?
• The breakdown of a compound by electricity is called what?
• What is Avogadro's number?
• How many grams of NaCl are present in 0.200 L of 0.150 M NaCl solution?
• Which gas diffuses faster: H2 or CO2?
• Which quantum number describes the orientation of the orbital in space?
• Which statement best describes a colloid?
• Which molecule has linear molecular geometry?
• Which law states that the total mass of the products equals the total mass of the reactants in a closed system?
• Two or more reactants combine to form a single product is known as what type of reaction?
• What is the molar ratio of NH3 to H2 in the reaction N2 + 3 H2 → 2 NH3?
• Which pair of elements is most characteristic of organic molecules?
• Which statement about activation energy is true?
• The electric attraction between a cation and anion is characteristic of which bond type?
• If a 0.100 M solution is diluted to 0.0100 M, what is the new volume if the original volume was 250 mL?
• What is the study of the rates of chemical reactions?
• In a redox reaction, which process occurs?
• Hydrolysis involves a reaction with water that breaks bonds.
• In a solution, the substance that dissolves is called
• In a neutralization reaction between a strong acid and a strong base, what are the typical products?
• Which quantum number indicates the energy level and describes the shell and size of the orbital?
• Which statement correctly distinguishes suspensions from solutions?
• What is the molarity of a solution containing 0.250 mol of solute in 0.500 L of solution?
• In a chemical equation A + B → AB + C, the reaction describes what?
• What is the percent by mass of oxygen in water (H2O)?
• Which statement best describes the relationship between bond order and bond length as bond order increases?
• Volume of NaOH required to reach equivalence with 50.0 mL of 0.100 M HCl?
• What type of reactions involve the transfer of electrons between species?
• Which statement best describes the effect of doubling the solute and solvent in a solution on the mass percent?
• A pure substance composed of only one kind of element is called what?
• Which statement correctly defines molar mass?
• The smallest building block of matter that defines an element's identity is called what?
• A region where an electron is likely to be found is called what?
• Which solution is a buffer: acetic acid with sodium acetate or pure water?
• What is the smallest unit of an element?
• The sum of the number of neutrons and protons in an atomic nucleus is the ...
• What is the formula unit of calcium fluoride?
• Which statement best describes ionization energy across a period?
• Hydrolysis is best described as which of the following?
• In an acid-base reaction, acids donate a proton.
• Which bond type results from sharing electrons to form molecules without transferring electrons?
• Balance the equation CH4 + O2 → CO2 + H2O.
• Which bonds hold organic molecules together as the primary linkage?
• A monoprotic acid donates how many protons per molecule?
• Define molality.
• In acid-base chemistry, bases accept a proton.
• Substances that cannot be further broken down are called?
• At STP, one mole of any ideal gas occupies what volume?
• When bases or hydroxide ions are added to a buffer solution, what typically happens?
• Which substances ionize incompletely in an aqueous solution?
• Heterogeneous mixtures with large often visible solutes that tend to settle out are called
• Solubility is influenced by which factors?
• Which law states mass is conserved in a chemical reaction?
• Which process increases entropy: dissolution of salt in water or crystallization from solution?
• In acid-base reactions, a base typically does what?
• Which statement best describes a buffer?
• A mixture is best described as which of the following?
• A mixture in which the composition is not uniform throughout is called
• In a solution, how are the solute and solvent distributed?
• Identify the oxidizing and reducing agents in the reaction Zn + Cu2+ → Zn2+ + Cu.
• The breakdown of a compound by heat is called what?
• Which term describes absorption and emission of quantum energy as electrons move between energy levels by jumps?
• Which bond type occurs when there is unequal sharing of electrons creating partial charges?
• A compound contains 40.0% carbon, 6.7% hydrogen, and 53.3% oxygen. What is its empirical formula?
• Why do atoms form bonds?
• Which subatomic particle orbits outside the nucleus and carries a negative charge?
• A substance made up of two or more substances combined in varying proportions is called a
• Which covalent bond occurs when electrons are shared equally between atoms?
• What is the mass percent of solute in a solution containing 5.0 g solute and 95.0 g solvent?
• Which of the following factors affect the dissolution rate?
• If the volume is reduced to one quarter of its original value while temperature and amount stay constant, what happens to pressure?
• Determine the oxidation state of manganese in MnO2.
• The species that loses electrons is referred to as what?
• What is a buffer solution?
• In a solution, the substance in which the solute dissolves is called
• What is the equation of the ideal gas law?
• In a reaction where ions are exchanged by two compounds to form new compounds (AC + BD → AD + BC), what type is this?
• Strong acids ionize completely in water. Which statement is true?
• Which statement correctly describes a reaction at equilibrium when the equilibrium constant Kc is greater than 1?
• What mass of NaCl corresponds to 0.50 moles?
• Which process is endothermic?
• Which statement best describes how the rate of a chemical reaction is measured?
• Which statement about molarity is true?
• Distinguish a strong electrolyte from a weak electrolyte.
• A homogeneous mixture of substances that cannot be separated by filtration or centrifugation is called a
• Which of the following is a pure substance?
• The weighted average of the atomic masses for the isotopes of an element is the ...
• The total number of protons and neutrons in the nucleus is called the ...
• In a physical change, what happens to the atoms and molecules?
• A monoprotic acid donates exactly how many protons per molecule?
• What is the pH of a solution with [H+] = 1.0 × 10^-7 M?
• If 0.500 L of 0.200 M solution is diluted to 0.0500 M, what is the final volume?
• Which of the following salts is typically soluble in water?
• A buffer solution resists changes in pH when small amounts of acid or base are added.
• Organic compounds such as proteins, lipids, carbohydrates, and nucleic acids are formed by which type of bonds?
• Which statement best differentiates endothermic and exothermic processes?
• Cathode rays originate from which particles?
• In a solution, the solute is what?
• A statement about catalysts and activation energy is true.
• A reactant is broken down into two or more products (AB → A + B) is called what?
• In the reaction N2 + 3 H2 → 2 NH3, what is the molar ratio of NH3 to N2?
• Which is a heterogeneous mixture?
• The rate of a chemical reaction is the change in concentration of the reactants or products per unit time; this is written as rate = ?
• Which statement best distinguishes a colloid from a true solution?
• Organic molecules predominantly contain which elements?
• Cations are positively charged ions formed when atoms lose electrons.
• What is the neutralization reaction between HCl and NaOH?
• For a reaction at equilibrium with Kc greater than 1, which statement is true?
• A reaction has theoretical yield 10 g and actual yield 7 g. What is percent yield?
• A more concentrated solution means more solute is dissolved. Which option best expresses this idea?
• Which type of covalent bond has one pair of electrons and is the weakest and longest?
• Isomerization is another term for rearrangement.
• A solution initially has 0.60 mol solute in 3.0 L. If it is diluted to 6.0 L, what is the new molarity?
• What are the attractive forces that hold atoms together into molecules?
• What determines the magnitude of the dipole moment in a simple diatomic molecule?
• Which of the following is NOT an intensive property?
• What is a consequence of lowering the activation energy for a reaction at a given temperature?
• Cathode rays are composed of which particles?
• In the neutral 56Fe atom, how many protons, neutrons, and electrons are present?
• In a double substitution reaction, what is exchanged between two compounds to form new compounds?
• What type of bonding results from the attraction between metal atoms and the surrounding electrons?
• What type of bonds are formed by transferring electrons between one atom to another and results in formation of cations and anions?
• Which type of bond is shortest and strongest among single, double, and triple bonds?
• Which quantum number describes the spin direction of an electron in an orbital?
• Spectral lines arise from electrons transitioning between what kind of energy states?
• The jumps electrons make between energy levels are called what?
• Which quantum number describes the orientation of an orbital relative to the axes?
• In a synthesis (combination) reaction, two or more substances react to form what?
• Which quantum number specifies the type of subshell (s, p, d, f)?
• Which factor increases the reaction rate by increasing the surface area of contact between reactants?
• In the reaction Zn + Cu2+ → Zn2+ + Cu, which species is reduced?
• As bond order increases, what happens to the bond length and bond strength?
• What term refers to negatively charged ions formed when atoms gain electrons?
• An example of a homogeneous mixture is
• A calorimeter contains 100 g of water and the water's temperature rises by 6°C. If c = 4.18 J/g°C, what is q for the water?
• Which statement best describes redox reactions?
• The species that gains electrons is referred to as what?
• Having the same number of protons defines which concept?
• Which of the following represents the ground-state electron configuration for chlorine (Z=17)?
• Which type of covalent bonds occurs when there is unequal sharing of electrons between atoms?
• If the equilibrium constant Kc for a reaction is greater than 1, what does that imply about the position of equilibrium?
• How many moles of H+ are present in 50 mL of 0.02 M HCl?
• How many moles are in 5.0 g of sodium chloride (NaCl) given a molar mass of 58.44 g/mol?
• Which type of change involves no new substances being formed, only rearrangement of atoms and molecules?
• In the balanced equation CH4 + 2 O2 → CO2 + 2 H2O, how many moles of O2 are consumed per mole of CH4?
• What is formed when two or more atoms are chemically bonded together?
• Which is an example of an intensive property?