Deck 7: Chemical Reactions

Question 1

Bubbles in water that appear during boiling show that a chemical reaction is occurring.

Answer 1

False

Question 2

Combustion reactions are a subcategory of oxidation-reduction reactions.

Answer 2

True

Question 3

An insoluble compound will completely dissolve in water.

Answer 3

False

Question 4

When compounds containing polyatomic ions dissolve,the polyatomic ions usually dissolve as intact units.

Question 5

The following equation IS balanced: CH₄ + 2O₂ → CO₂ + H₂O

Question 6

An aqueous solution is a homogeneous mixture of a substance with water and should be designated with the (l)abbreviation.

Question 7

The following reaction IS balanced: AgNO₃ + 2NH₄Cl → AgCl + (NH₄)₂NO₃

Question 8

Cl^-,Br^-,and I^- are mostly insoluble.

Question 9

Color change is evidence that a chemical reaction has occurred.

Question 10

The formation of a gas is evidence of a chemical reaction while the emission of light is not.

Question 11

The reaction of carbonate ion with magnesium ion to form solid magnesium carbonate is an example of an oxidation reduction reaction.

Question 12

The following equation IS balanced: 2 C₄H₁₀O + 13 O₂ → 8 CO2 + 10 H₂O

Question 13

The reaction of baking soda and vinegar to produce carbon dioxide gas is an example of a precipitation reaction.

Question 14

The formation of a new solid or gas is evidence of a chemical reaction.

Question 15

A strong electrolyte solution contains ionic compounds that completely dissociate in water.

Question 16

Li⁺,Na⁺,K⁺ and NH₄⁺ compounds are soluble.

Question 17

All ionic compounds dissolve in water.

Question 18

When balancing a chemical equation you may alter the coefficients but not the subscripts in the equation.

Question 19

The following equation IS balanced: HNO₃ + NaHSO₃ → NaNO₃ + H₂O + SO₂

Question 20

The following reaction IS balanced: BaCl₂ + H₂SO₄ → 2HCl + BaSO₄

Question 21

An acid-base reaction always produces a salt plus carbon dioxide.

Question 22

A precipitation reaction will occur when sodium chloride is mixed with potassium nitrate.

Question 23

Carbon dioxide gas is a product when an acid reacts with a carbonate or a bicarbonate.

Question 24

Mixing two aqueous solutions will always result in formation of a precipitate.

Question 25

One of the characteristics of an acid-base reaction is that this type of reaction forms water.

Question 26

Precipitation reactions always occur when two aqueous solutions are mixed.

Question 27

In an oxidation-reduction reaction,if one substance loses electrons,then another substance must gain electrons.

Question 28

Combustion reactions emit heat and so can be classified as endothermic.

Question 29

Mixing HNO₃ (aq)and NaHCO₃ (aq)will produce carbon dioxide gas as a product.

Question 30

The net ionic equation for the reaction of sodium hydroxide plus hydrochloric acid is .

Question 31

Decomposition reactions usually require energy to initiate the reaction.

Question 32

Evidence of a redox reaction is when a substance reacts with elemental oxygen.

Question 33

A precipitation reaction occurs when water is formed as a product.

Question 34

The key to predicting a precipitation reaction is the formation of an insoluble compound from soluble compounds.

Question 35

A net ionic equation shows all ionic species that are present in solution.

Question 36

A spectator ion is one that does not actively participate in a chemical reaction.

Question 37

A precipitate will form when you mix solutions of potassium chloride and lead nitrate.

Question 38

An oxidation-reduction reaction must involve reaction with oxygen.

Question 39

Evidence of a redox reaction is when one substance transfers protons to another substance.

Question 40

We remove the spectator ions from the complete ionic equation to form the net ionic equation.

Question 41

Which of the following is NOT typically a sign of a chemical reaction?

A)absorbing heat when chemicals are contacted with each other
B)emission of heat when chemicals are contacted with each other
C)emission of light when chemicals are contacted with each other
D)absorbing light when chemicals are contacted with each other
E)All of the above are signs of a chemical reaction.

Question 42

What are the coefficients for the following reaction when it is properly balanced? ___HCl + ___Mg → ___MgCl₂ + ___H₂

A)2,1,1,1
B)2,1,2,2
C)1,2,1/2,1
D)1,1,1,2
E)none of the above

Question 43

When the equation __Ca₃N₂ + __H₂O → __Ca(OH)₂ + __NH₃ is balanced,the coefficient of H₂O is:

A)2
B)3
C)6
D)12
E)none of the above

Question 44

What are the coefficients for the following reaction when it is properly balanced? ___nitric acid + ___sodium hydroxide → ___sodium nitrate + ___water

A)2,1,1,1
B)2,3,2,2
C)5,2,2,1
D)1,1,1,1
E)none of the above

Question 45

What are the coefficients for the following reaction when it is properly balanced? ___potassium iodide + ___lead (II)acetate → ___lead (II)iodide +___potassium acetate

A)2,1,1,1
B)2,1,1,2
C)3,2,2,1
D)1,1,2,2
E)none of the above

Question 46

The reaction 2 KClO₃ → 2 KCl + 3 O₂ would be correctly classified as a decomposition reaction.

Question 47

When water is heated,bubbles form in the water.Is this evidence of a chemical reaction? Why?

A)No,boiling water is a physical change.
B)Yes,the formation of a gas is evidence of a chemical reaction.
C)No,the formation of gas bubbles is a secondary chemical reaction which is ignored.
D)Yes,the formation of a gas is proof a new compound has been made.
E)none of the above

Question 48

A reaction which forms a solid product is an example of a(n):

A)oxidation-reduction reaction.
B)combustion reaction.
C)precipitation reaction.
D)gas evolution reaction.
E)none of the above

Question 49

What are the coefficients for the following reaction when it is properly balanced? ___Na₃PO₄ + ___Ba(NO₃)₂ → ___NaNO₃ + ___Ba₃(PO₄)₂

A)2,1,1,3
B)2,3,1,6
C)2,3,6,1
D)6,1,3,2
E)none of the above

Question 50

What are the coefficients for the following reaction when it is properly balanced? ___O₂ + ___CH₄ → ___CO₂ + ___H₂O

A)2,1,3,1
B)2,3,2,2
C)1,3,2,1
D)2,1,1,2
E)none of the above

Question 51

A reaction in which a substance reacts with oxygen,emitting heat and forming oxygen-containing compounds is an example of a(n):

A)acid-base reaction.
B)combustion reaction.
C)precipitation reaction.
D)gas evolution reaction.
E)none of the above

Question 52

A reaction which forms a gaseous product is an example of a(n)________.

A)oxidation-reduction reaction
B)combustion reaction
C)precipitation reaction
D)gas evolution reaction
E)none of the above

Question 53

Which of the following statements about balancing reactions is FALSE?

A)If there is no coefficient or subscript,a one is implied.
B)When coefficients are added the type of compounds is changed in the chemical reaction.
C)Subscripts are multiplied by the coefficients to determine the number of atoms in a compound.
D)Coefficients are added to compounds to ensure both sides of the reaction have equal numbers of each atom.
E)All of the above statements are true.

Question 54

When the equation __NO₂ + __H₂O + __O₂ → __HNO₃ is balanced,the coefficient of HNO₃ is:

A)2
B)3
C)4
D)5
E)none of the above

Question 55

When the equation,___O₂ + ___C₅H₁₂ → ___CO₂ + ___H₂O is balanced,the coefficient: of O₂ is:

A)3
B)4
C)5
D)8
E)none of the above

Question 56

Before a chemical equation can be written,one must know:

A)the atomic mass of all the elements involved.
B)the molar mass of all the compounds.
C)the symbols and formulas of all reactants and products.
D)the number of moles of all reactants and products.
E)none of the above.

Question 57

It has been shown that the ozone molecule (O₃)can be formed when a single oxygen atom (O)adds to a molecule of oxygen (O₂),so this type of reaction is known as a double displacement reaction.

Question 58

Which of the following is NOT evidence that a chemical reaction has occurred?

A)color change when chemicals are contacted with each other
B)solid formation when chemicals are contacted with each other
C)gas formation when chemicals are contacted with each other
D)emission of light when chemicals are contact with each other
E)All of the above are evidence of a chemical reaction.

Question 59

What are the coefficients for the following reaction when it is properly balanced? ___nitrogen monoxide + ___carbon monoxide → ___nitrogen +___carbon dioxide

A)2,1,1,2
B)2,2,1,2
C)2,2,2,1
D)1,1,2,2
E)none of the above

Question 60

When the equation,___N₂ + ___H₂ → ___NH₃ is balanced,the coefficient of hydrogen is:

A)1
B)2
C)3
D)4
E)none of the above

Question 61

Which of the following equations is NOT balanced properly?

A)2Cr + 6HCl → 2CrCl₃ + 3H₂
B)2NaHCO₃ → Na₂CO₃ + CO₂ + H₂O
C)Cr₂(SO₄)₃ + 6KOH → 2Cr(OH)₃ + 3 K₂SO₄
D)4NH₃ + 14O₂ → 4NO₂ + 6H₂O
E)none of the above

Question 62

The compound sodium sulfate is soluble in water.When this compound dissolves in water,which ion listed below would be present in solution?

A)SO₄^2-
B)S^2-
C)O^2-
D)Na₂²⁺
E)none of the above

Question 63

Which of the following compounds is SOLUBLE?

A)copper carbonate
B)calcium carbonate
C)potassium carbonate
D)strontium carbonate
E)none of the above

Question 64

All of the following compounds are soluble in water EXCEPT:

A)NaCl.
B)CaCl_2.
C)FeCl_3.
D)NH₄Cl.
E)PbCl_2.

Question 65

Which of the following compounds is INSOLUBLE?

A)magnesium phosphate
B)magnesium sulfate
C)magnesium iodide
D)magnesium nitrate
E)none of the above

Question 66

Sodium metal reacts with water to form aqueous sodium hydroxide and hydrogen gas.Which equation below best describes the balanced equation for this reaction?

A)Na + H₂O → NaOH (aq)+ H (g)
B)S + H₂O → SOH (aq)+ H (g)
C)Na + H₂O → NaOH (aq)+ H₂ (g)
D)2Na + 2H₂O → 2NaOH (aq)+ H₂ (g)
E)2Na + H₂O → Na₂OH (aq)+ H (g)

Question 67

Considering the following precipitation reaction:
Pb(NO₃)₂(aq)+ 2KI(aq)→ PbI₂(s)+ 2KNO₃(aq)
Which ion(s)would NOT be present in the net ionic equation?

A)Pb²⁺,NO₃^-
B)K⁺,NO₃^-
C)K^+, Pb²⁺
D)K⁺, I^-
E)All the above ions are in the net ionic equation.

Question 68

An aqueous solution is:

A)any liquid with another compound dissolved in it.
B)an ionic compound with water dissolved in it.
C)water with a molecular compound dissolved in it.
D)water with another compound dissolved in it.
E)none of the above

Question 69

Considering the following precipitation reaction:
Pb(NO₃)₂(aq)+ 2KI(aq)→ PbI₂(s)+ 2KNO₃(aq)
Which ion would NOT be present in the complete ionic equation?

A)Pb²⁺
B)K⁺
C)NO₃^-
D)I^-
E)All the above ions are in the complete ionic equation.

Question 70

Which of the following compounds is INSOLUBLE?

A)potassium acetate
B)lithium carbonate
C)magnesium bromide
D)aluminum sulfide
E)none of the above

Question 71

Considering the following precipitation reaction:
Pb(NO₃)₂(aq)+ 2KI(aq)→ PbI₂(s)+ 2KNO₃(aq)
Which ion(s)would NOT be spectator ions?

A)Pb²⁺,NO₃^-
B)K⁺,I^-
C)NO₃^-,Pb²⁺
D)Pb²⁺,I ^-
E)All the above ions are in the net ionic equation.

Question 72

Considering the following precipitation reaction:
Pb(NO₃)₂(aq)+ 2KI(aq)→ PbI₂(s)+ 2KNO₃(aq)
Which compound would not form ions in the complete ionic equation?

A)PbI₂
B)KNO₃
C)Pb(NO₃)₂
D)KI
E)All compounds form ions in the complete ionic equation.

Question 73

A precipitate is expected to be formed when an aqueous solution of sodium sulfate is added to an aqueous solution of:

A)iron(III)chloride.
B)potassium chloride.
C)magnesium chloride.
D)barium chloride.
E)none of the above

Question 74

In writing the chemical equation for a precipitation reaction,what abbreviation of the physical state must appear with one of the products?

A)(s)
B)(g)
C)(l)
D)(w)
E)none of the above

Question 75

If you had an aqueous mixture that contained Ag⁺,K⁺,and Pb²⁺ cations,how many different solids could precipitate if a chloride solution was added?

A)1
B)2
C)3
D)4
E)no solids will precipitate

Question 76

Several grams of sodium chloride are stirred into a glass of water and are no longer visible to the eye.Which of the following statements is FALSE?

A)The sodium chloride solid has dissociated into its component ions.
B)An aqueous solution has been prepared.
C)No precipitate has formed.
D)Sodium chloride is insoluble in water.
E)All of the statements are true.

Question 77

What type of a reaction occurs when a potassium nitrate solution is mixed with a barium acetate solution?

A)precipitation
B)acid-base neutralization
C)oxidation-reduction
D)gas evolution
E)no reaction

Question 78

When solid NaCl is stirred into water,which of the following is NOT true?

A)Individual sodium and chloride ions are present.
B)The solution will conduct electricity.
C)The solution will taste salty.
D)The NaCl will fail to dissociate.
E)none of the above

Question 79

What would be the formula of the precipitate that forms when Pb(NO₃)₂ (aq)and K₂SO₄ (aq)are mixed?

A)K(NO₃)₂
B)PbSO₄
C)PbK₂
D)H₂O
E)none of the above

Question 80

Which of the following compounds is SOLUBLE?

A)aluminum hydroxide
B)aluminum sulfide
C)aluminum carbonate
D)aluminum sulfate
E)none of the above