Deck 13: Chemical Reactions

Question 1

A chemical reaction generally has a great effect on an atom's

A) nuclear structure.
B) mass.
C) nuclear binding energy.
D) electron configuration.

Answer 1

D

Question 2

Which one of the following is a physical change?

A) Rusting of iron
B) Fermenting of grape juice
C) Souring of milk
D) Sharpening a pencil

Answer 2

D

Question 3

The equation 4H₂O₂ → 4H₂O + 2O₂ is 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.

Answer 3

D

Question 4

The equation 1/2 N₂ + 3/2 H₂→ NH₃ is not appropriately 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.

Question 5

The process of melting lead is an example of

A) a physical change.
B) a chemical change.
C) a physical property.
D) a chemical property.

Question 6

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

Question 7

A chemical reaction is balanced by applying all except which 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.

Question 8

The substances that are diminished in a chemical reaction are called the

A) products.
B) reactants.
C) chemicals.
D) precipitates.

Question 9

Which of the following does not take place in a chemical reaction?

A) New substances are formed.
B) Neutrons are released.
C) Energy is released or absorbed.
D) Reactants disappear.

Question 10

The substances that are formed by a chemical reaction are called the

A) products.
B) reactants.
C) chemicals.
D) precipitates.

Question 11

Which of the following is an example of a chemical property?

A) Al has a density of 2.70 g/cm³.
B) Diamond is the hardest substance known.
C) Limestone will yield CO₂ when heated.
D) CO₂ will freeze at -78°C.

Question 12

When the equation NH₄NO₃→ N₂O + H₂O is balanced,the coefficient of H₂O is

A) 3.
B) 4.
C) 2.
D) 1.

Question 13

The equation H₂O₂ → H₂O + O is not correctly 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.

Question 14

One reactant of photosynthesis is

A) hydrogen.
B) oxygen.
C) carbon dioxide.
D) methane.

Question 15

When the equation NH₄NO₃→ N₂O + H₂O is balanced,the total of all the coefficients (both written and "understood")is

A) 3.
B) 4.
C) 7.
D) 8.

Question 16

A chemical reaction is at equilibrium when

A) no reactants are changing to products.
B) the forward and reverse reactions proceed at the same rate.
C) the total mass has become constant.
D) the temperature is no longer changing.

Question 17

Which of the following is a chemical change?

A) Dry ice subliming
B) Limestone being crushed to powder
C) Paper being shredded
D) Sulfur burning

Question 18

One product of photosynthesis is

A) hydrogen.
B) oxygen.
C) carbon dioxide.
D) methane.

Question 19

The equation 1H₂SO₄ → 1H₂O + 4O₂ is 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.

Question 20

Which one of the following is not a physical property of matter?

A) Specific heat
B) Boiling point
C) Density
D) Flammability

Question 21

What basic type of reaction is illustrated by the general equation AB + CD → AD + BC?

A) Combination
B) Decomposition
C) Double-replacement
D) Single-replacement

Question 22

When the equation Sb₂S₃ + HCl → SbCl₃ + H₂S is balanced,the total of all the coefficients (both written and "understood")is

A) 10.
B) 14.
C) 9.
D) 12.

Question 23

Which type of reaction is 4Al + 3O₂→ 2Al₂O₃?

A) Decomposition
B) Combination
C) Double-replacement
D) Single-replacement

Question 24

The energy necessary to start a chemical reaction is called the ______________ energy.

A) exothermic
B) activation
C) endothermic
D) combustion

Question 25

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.

Question 26

In general,slow reactions

A) are exothermic.
B) are endothermic.
C) have low activation energies.
D) have high activation energies.

Question 27

When the equation NH₄NO₃→ N₂O + H₂O is balanced,the coefficient of N₂O is

A) 3.
B) 4.
C) 2.
D) 1.

Question 28

What basic type of reaction is illustrated by the general equation A + BC → B + AC?

A) Combination
B) Decomposition
C) Double-replacement
D) Single-replacement

Question 29

What basic type of reaction is illustrated by the general equation A + B → AB?

A) Combination
B) Decomposition
C) Double-replacement
D) Single-replacement

Question 30

When the equation Sb₂S₃ + HCl → SbCl₃ + H₂S is balanced,the coefficient of SbCl₃ is

A) 3.
B) 1.
C) 2.
D) 4.

Question 31

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

Question 32

When the equation Sb₂S₃ + HCl → SbCl₃ + H₂S is balanced,the coefficient of HCl is

A) 1.
B) 6.
C) 2.
D) 4.

Question 33

In general,fast reactions

A) are exothermic.
B) are endothermic.
C) have low activation energies.
D) have high activation energies.

Question 34

When the equation Al + O₂→ Al₂O₃ is balanced,the coefficient of Al₂O₃ is

A) 1
B) 2
C) 3
D) 4

Question 35

What basic type of reaction is illustrated by the general equation AB → A + B?

A) Combination
B) Decomposition
C) Double-replacement
D) Single-replacement

Question 36

When the equation Al + O₂→ Al₂O₃ is balanced,the coefficient of Al is

A) 1
B) 2
C) 3
D) 4

Question 37

When the equation Sb₂S₃ + HCl → SbCl₃ + H₂S is balanced,the coefficient of H₂S is

A) 3.
B) 1.
C) 2.
D) 4.

Question 38

When the equation Al + O₂→ Al₂O₃ is balanced,the coefficient of O₂ is

A) 1
B) 2
C) 3
D) 4

Question 39

When a hydrocarbon or carbon-hydrogen-oxygen compound is burned completely,the products are

A) CO₂ and H₂O.
B) CH₂ and O₂.
C) CO and H₂.
D) C and H₂.

Question 40

Which type of reaction is 2Cu(NO₃)₂→ 2CuO + 4NO₂ + O₂?

A) Single-replacement
B) Double-replacement
C) Combination
D) Decomposition

Question 41

A solution with a pH of 14 is

A) strongly acidic.
B) weakly basic.
C) strongly basic.
D) weakly acidic.

Question 42

When the equation Ga + Br₂ → GaBr₃ is balanced,the total of all the coefficients (both written and "understood")is

A) 4.
B) 3.
C) 6.
D) 7.

Question 43

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

Question 44

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.

Question 45

The rate of a chemical reaction would be decreased by

A) stirring the reactants.
B) increasing the concentration of the reactants.
C) adding a catalyst to the reactants.
D) cooling the reactants.

Question 46

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.

Question 47

A solution with a pH of 8 is

A) strongly acidic.
B) weakly basic.
C) strongly basic.
D) weakly acidic.

Question 48

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

Question 49

What type of reaction gives CO₂ and 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

Question 50

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.

Question 51

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

Question 52

The coefficients needed to balance the equation Ga + Br₂ → GaBr₃ are,respectively,

A) 4, 3, and 2.
B) 2, 3, and 2.
C) 1, 3, and 2.
D) 2, 1, and 2.

Question 53

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.

Question 54

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.

Question 55

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

Question 56

A substance that increases the rate of a chemical reaction but is not consumed in the reaction is called

A) an oxidizing agent.
B) a catalyst.
C) an activation agent.
D) a reducing agent.

Question 57

A solution with a pH of 1 is

A) strongly acidic.
B) weakly basic.
C) strongly basic.
D) weakly acidic.

Question 58

A solution with a pH of 6 is

A) strongly acidic.
B) weakly basic.
C) strongly basic.
D) weakly acidic.

Question 59

Which of the following is not a 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

Question 60

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

Question 61

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.

Question 62

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.

Question 63

By definition,the removal of oxygen from a compound is called

A) neutralization.
B) reduction.
C) oxidation.
D) displacement.

Question 64

By definition,the loss of electrons by an atom or ion is called

A) neutralization.
B) reduction.
C) oxidation.
D) displacement.

Question 65

The compound Mg(OH)₂ is commonly known as

A) Epsom salt.
B) Alka-Seltzer.
C) smelling salts.
D) milk of magnesia.

Question 66

Acids give what ions in aqueous solutions?

A) SO₄^2-
B) Cl^-
C) OH^-
D) H⁺

Question 67

What is the identity of stomach acid?

A) HC₂H₃O₂
B) H₂CO₃
C) HCl
D) H₃PO₄

Question 68

In the reaction between HCl and Na₂CO₃,which gas is formed?

A) H₂
B) CH₄
C) CO₂
D) O₂

Question 69

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.

Question 70

Which type of reaction is AlCl₃ + 3KOH → Al(OH)₃ + 3KCl?

A) Single-replacement
B) Double-replacement
C) Decomposition
D) Combination

Question 71

Which of the following is a strong acid?

A) Citric acid
B) Nitric acid
C) Phosphoric acid
D) Acetic acid

Question 72

Which of the following compounds would you expect to be soluble in water?

A) PbCO₃
B) Ag₂CO₃
C) CuCO₃
D) K₂CO₃

Question 73

Which of the following compounds would not precipitate from an aqueous solution during a double-replacement reaction?

A) Cu(NO₃)₂
B) CuCO₃
C) AgCl
D) AlPO₄

Question 74

Which of the following is a weak base?

A) NH₃
B) NaOH
C) KOH
D) Ca(OH)₂

Question 75

Which type of reaction is 2Fe₂O₃+ 3C→ 4Fe+ 3CO₂?

A) Decomposition
B) Combination
C) Double-replacement
D) Single-replacement

Question 76

Water solutions of which of the following are basic?

A) Soft drinks
B) Baking soda
C) Lemonade
D) Vinegar

Question 77

Which acid is present in vinegar?

A) HCl
B) H₃PO₄
C) H₂SO₄
D) HC₂H₃O₂

Question 78

Which type of reaction is Zn + 2HCl → ZnCl₂ + H₂?

A) Decomposition
B) Combination
C) Double-replacement
D) Single-replacement

Question 79

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.

Question 80

Which of the following is a weak acid?

A) Hydrochloric acid
B) Nitric acid
C) Sulfuric acid
D) Acetic acid