Q&A Hero

Q: How many atoms of oxygen are contained in 44 g of carbon dioxide, CO2?A) 3.01 x 1023B) 12.0 x 1023C) 6.02 x 1023D) None of these

Q: How many moles would 44 g of carbon dioxide, CO2, be?A) 3.0B) 2.0C) 1.0D) None of these

Q: Avogadro's number has a numerical value ofA) 6.02 x 1023.B) 1.00 x 1023.C) 3.01 x 1023.D) none of these.

Q: In the reaction 2Al + 3F22AlF3, the fluorine A) is reduced. B) loses electrons. C) is oxidized. D) is the catalyst.

Q: In the reaction 2Al + 3F22AlF3, the aluminumA) is reduced.B) gains electrons.C) is oxidized.D) is the catalyst.

Q: In the activity series, Zn is more active than Pb. This means that A) Zn is a better catalyst than Pb. B) Zn loses its electrons more easily than Pb. C) Pb is more readily oxidized than Zn. D) none of these

Q: In order, from top to bottom, in the activity series come Li, K, Ba, Na, Al, Zn, Sn, and Pb. Therefore, A) tin is more active than lead. B) zinc is more active than aluminum. C) potassium is more active than lithium. D) sodium is more active than barium.

Q: In order, from top to bottom, in the activity series come K, Zn, Pb, H, Cu, and Au. Therefore, A) adding Pb to ZnCl2will release Zn. B) adding Cu to HCl will release hydrogen. C) adding Au to HCl will release hydrogen. D) adding Cu to AuCl3will release Au.

Q: By definition, the gain of electrons by an atom or ion is called A) neutralization. B) reduction. C) oxidation. D) displacement.

Q: By definition, the addition of oxygen to a substance is called A) neutralization. B) reduction. C) oxidation. D) displacement.

Q: By definition, the removal of oxygen from a compound is called A) neutralization. B) reduction. C) oxidation. D) displacement.

Q: By definition, the loss of electrons by an atom or ion is called A) neutralization. B) reduction. C) oxidation. D) displacement.

Q: All but the most inactive metals react with acids to give A) hydrogen and the metal salt. B) hydrogen and the metal hydroxide. C) hydrogen and the metal oxide. D) oxygen and the metal hydride.

Q: Hydrogen gas would be a product of the reaction of A) vinegar and baking soda. B) iron and hydrochloric acid. C) oxygen and methane. D) HCl and NaOH.

Q: Which type of reaction is 2Fe2O3+ 3C4Fe+ 3CO2? A) Decomposition B) Combination C) Double-replacement D) Single-replacement

Q: Which type of reaction is Zn + 2HCl ZnCl2+ H2? A) Decomposition B) Combination C) Double-replacement D) Single-replacement

Q: What is the identity of stomach acid? A) HC2H3O2 B) H2CO3 C) HCl D) H3PO4

Q: The compound Mg(OH)2is commonly known as A) Epsom salt. B) Alka-Seltzer. C) smelling salts. D) milk of magnesia.

Q: Which type of reaction is AlCl3+ 3KOH Al(OH)3+ 3KCl? A) Single-replacement B) Double-replacement C) Decomposition D) Combination

Q: Water solutions of which of the following are basic? A) Soft drinks B) Baking soda C) Lemonade D) Vinegar

Q: Which of the following is a weak base? A) NH3 B) NaOH C) KOH D) Ca(OH)2

Q: A weak acid is one that does not A) taste very sour. B) ionize appreciably in water. C) form hydrogen gas when a metal is dropped in. D) neutralize OH-ions.

Q: Which of the following is a strong acid? A) Citric acid B) Nitric acid C) Phosphoric acid D) Acetic acid

Q: Which of the following is a weak acid? A) Hydrochloric acid B) Nitric acid C) Sulfuric acid D) Acetic acid

Q: In the reaction between HCl and Na2CO3, which gas is formed? A) H2 B) CH4 C) CO2 D) O2

Q: Which of the following compounds would notprecipitate from an aqueous solution during a double-replacement reaction? A) Cu(NO3)2 B) CuCO3 C) AgCl D) AlPO4

Q: Which of the following compounds would you expect to be soluble in water? A) PbCO3 B) Ag2CO3 C) CuCO3 D) K2CO3

Q: Which acid is present in vinegar? A) HCl B) H3PO4 C) H2SO4 D) HC2H3O2

Q: An ionic compound composed of a cation other than H+ and an anion other than OH-is called a(n) A) salt. B) precipitate. C) conjugate base. D) electrolyte.

Q: Acids give what ions in aqueous solutions? A) SO42- B) Cl- C) OH- D) H+

Q: A compound that contains water molecules as part of its formula is called A) a hydrate. B) an anhydride. C) a hydride. D) a hydroxide.

Q: An acid added to a base will produce a A) salt and hydrogen ions. B) salt and hydroxide ions. C) salt and water. D) stronger acid and base.

Q: Which answer is incorrect? A base is a substance that, when dissolved in water, A) reacts with an acid to neutralize its properties. B) reacts with many metals to liberate O2. C) changes the color of litmus dye from red to blue. D) conducts electricity.

Q: Which of the following is nota property of an aqueous solution of an acid? A) Reacts with many metals to liberate hydrogen gas B) Changes the color of litmus dye from red to blue C) Tastes sour D) Conducts an electric current

Q: A solution with a pH of 14 is A) strongly acidic. B) weakly basic. C) strongly basic. D) weakly acidic.

Q: A solution with a pH of 8 is A) strongly acidic. B) weakly basic. C) strongly basic. D) weakly acidic.

Q: A solution with a pH of 6 is A) strongly acidic. B) weakly basic. C) strongly basic. D) weakly acidic.

Q: A solution with a pH of 1 is A) strongly acidic. B) weakly basic. C) strongly basic. D) weakly acidic.

Q: What type of reaction gives CO2and H2O as the only products? A) Complete hydrocarbon combustion B) Acid"base reaction C) Acid"carbonate reaction D) Single-replacement, with an acid and an active metal

Q: The rate of a chemical reaction would be increased by A) increasing the surface area of the reactants. B) increasing the concentration of the reactants. C) adding a catalyst to the reactants. D) heating the reactants. E) all of the above.

Q: The rate of a chemical reaction would be decreasedby A) stirring the reactants. B) increasing the concentration of the reactants. C) adding a catalyst to the reactants. D) cooling the reactants.

Q: For an endothermic reaction, the energy barrier is ______________ on the reactant side than on the product side. A) greater B) not different in size C) smaller

Q: For an exothermic reaction, the energy barrier is ______________ on the reactant side than on the product side. A) smaller B) not different in size C) greater

Q: When carbon combines with oxygen, energy is released to the surroundings. Thus this reaction A) is an acid"base reaction. B) is endothermic. C) never reaches equilibrium. D) is exothermic.

Q: Increased temperature usually leads to an increase in reaction rate because collisions are A) more violent only. B) more frequent only. C) both more violent and more frequent. D) none of these

Q: Increased reactant concentration usually leads to an increase in reaction rate, because collisions are A) more violent only. B) more frequent only. C) both more violent and more frequent. D) none of these

Q: A substance that increases the rate of a chemical reaction but is notconsumed in the reaction is called A) an oxidizing agent. B) a catalyst. C) an activation agent. D) a reducing agent.

Q: When the equation Ga + Br2GaBr3is balanced, the total of all the coefficients (both written and "understood") is A) 4. B) 3. C) 6. D) 7.

Q: The coefficients needed to balance the equation Ga + Br2GaBr3are, respectively,A) 4, 3, and 2.B) 2, 3, and 2.C) 1, 3, and 2.D) 2, 1, and 2.

Q: When there is a net release of energy in a chemical reaction, it is called a(n) ______________ reaction. A) exothermic B) activation C) endothermic D) combustion

Q: When there is a net absorption of energy in a chemical reaction, it is called a(n) ______________ reaction. A) exothermic B) activation C) endothermic D) combustion

Q: The energy necessary to start a chemical reaction is called the ______________ energy. A) exothermic B) activation C) endothermic D) combustion

Q: When a hydrocarbon or carbon-hydrogen-oxygen compound is burned completely, the products are A) CO2and H2O. B) CH2and O2. C) CO and H2. D) C and H2.

Q: In general, fast reactions A) are exothermic. B) are endothermic. C) have low activation energies. D) have high activation energies.

Q: In general, slow reactions A) are exothermic. B) are endothermic. C) have low activation energies. D) have high activation energies.

Q: What basic type of reaction is illustrated by the general equation AB+ CDAD + BC? A) Combination B) Decomposition C) Double-replacement D) Single-replacement

Q: What basic type of reaction is illustrated by the general equation A+ BCB + AC? A) Combination B) Decomposition C) Double-replacement D) Single-replacement

Q: What basic type of reaction is illustrated by the general equation A+ BAB? A) Combination B) Decomposition C) Double-replacement D) Single-replacement

Q: What basic type of reaction is illustrated by the general equation ABA+ B? A) Combination B) Decomposition C) Double-replacement D) Single-replacement

Q: Which type of reaction is 2Cu(NO3)22CuO + 4NO2+ O2? A) Single-replacement B) Double-replacement C) Combination D) Decomposition

Q: Which type of reaction is 4Al + 3O22Al2O3? A) Decomposition B) Combination C) Double-replacement D) Single-replacement

Q: The coefficients needed to balance the reaction Sb2S3+ HCl SbCl3+ H2S are, respectively, A) 1, 2, 1, and 1. B) 2, 1, 3, and 1. C) 1, 2, 1, and 3. D) 1, 6, 2, and 3. E) 1, 1, 1, and 1.

Q: When the equation Al + O2Al2O3 is balanced, the coefficient of Al2O3 is A) 1 B) 2 C) 3 D) 4

Q: When the equation Al + O2Al2O3 is balanced, the coefficient of O2 is A) 1 B) 2 C) 3 D) 4

Q: When the equation Al + O2Al2O3 is balanced, the coefficient of Al isA) 1B) 2C) 3D) 4

Q: When the equation Sb2S3+ HCl SbCl3+ H2S is balanced, the coefficient of SbCl3 isA) 3.B) 1.C) 2.D) 4.

Q: When the equation Sb2S3+ HCl SbCl3+ H2S is balanced, the coefficient of H2S isA) 3.B) 1.C) 2.D) 4.

Q: When the equation Sb2S3+ HCl SbCl3+ H2S is balanced, the coefficient of HCl isA) 1.B) 6.C) 2.D) 4.

Q: When the equation Sb2S3+ HCl SbCl3+ H2S is balanced, the total of all the coefficients (both written and "understood") isA) 10.B) 14.C) 9.D) 12.

Q: When the equation NH4NO3N2O + H2O is balanced, the coefficient of N2O isA) 3.B) 4.C) 2.D) 1.

Q: When the equation NH4NO3N2O + H2O is balanced, the coefficient of H2O isA) 3.B) 4.C) 2.D) 1.

Q: When the equation NH4NO3N2O + H2O is balanced, the total of all the coefficients (both written and "understood") isA) 3.B) 4.C) 7.D) 8.

Q: The equation H2O2 H2O + O is notcorrectly written because A) the number of atoms of each element on each side is not the same. B) the mass indicated on each side is not the same. C) oxygen is diatomic. D) hydrogen peroxide decomposes to H2O and H.

Q: The equation 1H2SO41H2O + 4O2is not appropriately written because A) oxygen is not diatomic. B) fractional coefficients are not generally used. C) the number of atoms of each element on each side is not the same. D) the simplest set of coefficients has not been used.

Q: The equation 4H2O24H2O + 2O2is not appropriately written because A) oxygen is not diatomic. B) fractional coefficients are not generally used. C) the number of atoms of each element on each side is not the same. D) the simplest set of coefficients has not been used.

Q: The equation 1/2 N2+ 3/2 H2NH3is notappropriately written because A) the number of atoms of each element on each side is not the same. B) fractional coefficients are not generally used. C) nitrogen is not diatomic. D) the product is N2H4, not NH3.

Q: A balanced chemical equation will have the same ______________ on each side. A) number of moles B) number of molecules C) mass of each compound D) number of atoms of each element

Q: A chemical reaction is balanced by applying all exceptwhich of the following principles? A) No atoms are gained, lost, or changed in identity. B) Only the numbers preceding formulas can be changed. C) The set of smallest whole numbers should be used. D) Subscripts in the formulas may be changed if necessary.

Q: A chemical reaction generally has a great effect on an atom's A) nuclear structure. B) mass. C) nuclear binding energy. D) electron configuration.

Q: The substances that are diminished in a chemical reaction are called the A) products. B) reactants. C) chemicals. D) precipitates.