Deck 6: Chemical Reactions

Question 1

What is the word "carb" short for?

A) carbon
B) carbohydrate
C) carburetor
D) carbonics
E) carbocation

Answer 1

B

Question 2

What is the general formula of a carbohydrate?

A) C_xH_y
B) C_x(HO)_y
C) C_xO_y
D) C_x(H₃O)_y
E) C_x(H₂O)_y

Answer 2

E

Question 3

A chemical reaction produces changes in

A) matter only.
B) energy only.
C) matter and energy.
D) matter, energy, and atomic nuclei.

Answer 3

C

Question 4

Choose the chemical reaction that best represents the combustion of methane (CH?₄).

A) CH₄ $\rightarrow$ CO₂ + 2 H₂O
B) CO₂ + 2 H₂O $\rightarrow$ CH₄ + 2 O₂
C) CH₄ + 2 H₂O $\rightarrow$ CO₂ + 4 H₂
D) CH₄ + 2 O₂ $\rightarrow$ CO₂ + 2 H₂O
E) CH₄ $\rightarrow$ C + 2 H₂

Question 5

All of the statements below about chemical reactions are true except

A) elements in the reactants change into new product elements.
B) reactants change into products.
C) total mass remains unchanged.
D) atoms are neither created nor destroyed.
E) atoms in reactant molecules change partners to form new molecules.

Question 6

Atoms are neither created nor destroyed during chemical reactions. This is because all chemical reactions obey the law of

A) increasing entropy.
B) atomic energy.
C) multiple proportions.
D) conservation of energy.
E) conservation of mass.

Question 7

The following unbalanced chemical equation represents the combustion of butane (C₄H₁₀), a fuel used in lighters and portable stoves. What coefficient should be placed in front of H₂O, when balanced?
__C₄H₁₀ + __O₂ $\rightarrow$ __CO₂ + __H₂O

A) 5
B) 10
C) 13
D) 2
E) 4

Question 8

The following unbalanced chemical equation represents the combustion of butane (C₄H₁₀), a fuel used in lighters and portable stoves. What coefficient should be placed in front of C₄H₁₀, when balanced?
__C₄H₁₀ + __O₂ $\rightarrow$ __CO₂ + __H₂O

A) none
B) 1
C) 2
D) 4
E) 8

Question 9

In the following unbalanced chemical equation, what coefficient should be placed in front of H₂O, when balanced?
__PCl₃ + __H₂O $\rightarrow$ __H₃PO₃ + __HCl

A) 2
B) 3
C) 6
D) none

Question 10

The following unbalanced equation represents formation of sulfuric acid, a highly corrosive compound found in acid rain. When the equation is balanced, which coefficient should be placed in front of SO₂?
__SO₂ + __O₂ + __H₂O $\rightarrow$ __H₂SO₄

A) none
B) 1/2
C) 2
D) 3
E) 4

Question 11

Which coefficient should be placed in front of the H₂O when balancing the following equation?
(NH₄)₂Cr₂O_7(s) $\rightarrow$ Cr₂O_3(s) + N_2(g) + H₂O_(g)

A) 1
B) 2
C) 3
D) 4
E) 8

Question 12

Alcohols are good fuels, undergoing combustion to produce energy. The following is an unbalanced equation for the combustion of ethanol. What coefficients should be placed in the blanks from left to right when balanced?
__C₂H₆O + __O₂ $\rightarrow$ __CO₂ + ??__H₂O

A) 0; 2; 1; 2
B) 1; 3; 3; 2
C) 1; 3; 2; 3
D) 2; 6; 4; 6
E) 2; 1; 1; 2

Question 13

Alcohols are good fuels, undergoing combustion to produce energy. Below is an unbalanced equation for the combustion of methanol. What coefficients should be placed in the blanks from left to right when balanced?
__CH₃OH + __O₂ $\rightarrow$ __CO₂ + ??__H₂O

A) 2; 1; 2; 3
B) 2; 3; 2; 4
C) 1; 2; 1; 2
D) 3; 6; 4; 8
E) 2; 3; 4; 2

Question 14

The fermentation of fruit juice to produce wine involves the conversion of glucose to ethanol and carbon dioxide. Which coefficients should be placed in the blanks from left to right, when balancing?
__C₆H₁₂O₆ $\rightarrow$ __C₂H₆O + __CO₂

A) 1; 2; 2
B) 2; 4; 3
C) 2; 4; 5
D) 1; 4; 3
E) 1; 4; 2

Question 15

In the following reaction of sodium metal with water to produce sodium hydroxide and hydrogen gas, what coefficients should be placed in the blanks from left to right, when balancing?
__Na + __H₂O $\rightarrow$ __NaOH + __H₂

A) 1; 3; 2; 1
B) 1; 1; 1; 2
C) 1; 1; 1; 1
D) 2; 2; 2; 1
E) 1; 2; 1; 2

Question 16

In the following unbalanced chemical equation, what coefficients should be placed in the blanks from left to right, when balancing?
__NH₃ + __O₂ $\rightarrow$ __NO + __H₂O

A) 2; 3; 2; 3
B) 1; 2; 1; 2
C) 1; 2; 1; 3
D) 4; 5; 4; 6
E) 4; 6; 4; 7

Question 17

What is the meaning of the letter "s" in the following chemical equation?
C_(s) + O_2(g) $\rightarrow$ CO_2(g)

A) single
B) sigma
C) solid
D) soft
E) stoichiometry

Question 18

The numerical ratios of reactants and products in a chemical reaction is called

A) stoicism.
B) stoichiometry.
C) fractional coefficients.
D) proportionality.
E) chemical formula.

Question 19

Which statement about carbon monoxide is false?

A) It is produced during combustion reactions.
B) It causes tens of thousands of emergency room visits per year in the United States.
C) It has an offensive odor.
D) It is produced under conditions of limited oxygen.
E) In the body, it prevents oxygen from being delivered to cells.

Question 20

Why is carbon monoxide dangerous to humans?

A) It constricts the size of the arteries that lead away from the heart.
B) It replaces the body's phosphorus and breaks down the structure of DNA.
C) It destroys cell membranes.
D) It binds strongly to iron ions in hemoglobin, preventing oxygen binding.
E) It interferes with synaptic signals in the brain.

Question 21

Pictured here is the periodic table block for the element aluminium. How much does one atom of aluminium weigh?

A) 13 g
B) 13 amu
C) 26.982 g
D) 26.982 amu
E) Not enough information is given.

Question 22

Pictured here is the periodic table block for the element phosphorus. How much does one atom of phosphorus weigh?

A) 15 amu
B) 15 g
C) 30.974 amu
D) 30.974 g
E) Not enough information is given.

Question 23

Pictured here is the periodic table bock for the element sulfur. How much does one mole of sulfur atoms weigh?

A) 32.065 amu
B) 32.065 g
C) 16 amu
D) 16 g
E) 6.022 *10²³ g

Question 24

Pictured here is the periodic table block for the element phosphorus. How much does one atom of phosphorus weigh?

A) 6.022 *10²³ g
B) 30.974 amu
C) 30.974 g
D) 15 amu
E) 15 g

Question 25

Pictured here is the periodic table block for the element aluminium. How many atoms are contained in one mole of aluminium?

A) 13
B) 26.982
C) 1 million
D) 1 trillion
E) 6.022 *10²³

Question 26

A small gold coin weighs 21.4 g. How many moles of gold are contained in the coin?

A) 9.20 mol
B) 1.29 * 10²⁵ mol
C) 3.55 *10^-23 mol
D) 6.02 * 10²³ mol
E) 0.109 mol

Question 27

A balloon contains 0.015 moles of helium. What mass of helium does the balloon contain?

A) 270 g
B) 0.0034 g
C) 0.060 g
D) 4.0 g
E) 9.03 * 10²¹ g

Question 28

A silver earring weighs 16.3 g. How many atoms of silver are contained in the earring?

A) 0.151 atoms
B) 7 atoms
C) 9.81 * 10²⁴ atoms
D) 9.09 *10²² atoms
E) 3.99 * 10²⁴ atoms

Question 29

An average banana contains 0.422 grams of potassium. How many atoms of potassium is this?

A) 6.50 * 10²¹ atoms
B) 1.07 *10^-2 atoms
C) 2.54 * 10²³ atoms
D) 92.7 atoms
E) 1.34 *10²² atoms

Question 30

A cup of milk contains 300 mg of calcium. Convert this quantity to moles.

A) 7.5 mol
B) 7.5 *10^-3 mol
C) 7.5 *10³ mol
D) 12 mol
E) 1.2*10⁴ mol

Question 31

Determine the mass in grams of 2.00 *10¹⁸ sulfur atoms.

A) 1.60 *10^-17 g
B) 6.41 *10¹⁹ g
C) 3.32 * 10^-6 g
D) 1.07 *10^-4 g
E) 1.04 *10^-7 g

Question 32

A tube of toothpaste contains 0.0095 moles of fluoride (F). Convert this amount into grams.

A) 0.00053 g
B) .086 g
C) 0.0011 g
D) 5.7 *10²¹ g
E) 0.18 g

Question 33

Calculate the molar mass of phosphoric acid, H₃PO₄.

A) 48.0 g/mol
B) 98.0 g/mol
C) 50.0 g/mol
D) 96.0 g/mol

Question 34

Calculate the molar mass of aluminium carbonate, Al₂(CO₃)₃.

A) 114 g/mol
B) 234 g/mol
C) 210 g/mol
D) 138 g/mol
E) 207 g/mol

Question 35

What mass of sulfur dioxide is found in 1.56 mol SO₂?

A) 99.9 g
B) 0.0244 g
C) 64.0 g
D) 9.39 *10²³ g
E) 49.9 g

Question 36

Sucralose (C₁₂H₁₉Cl₃O₈), an artificial sweetener, is the main ingredient in Splenda. Calculate the amount, in moles, of 4.00 g of sucralose.

A) 6.64 *10^-24 mol
B) 2.41* 10²⁴ mol
C) 1590 mol
D) 0.0101 mol

Question 37

How many molecules are contained in 0.650 g acetaminophen (C₈H₉NO₂)?

A) 3.91 *10²³ molecules
B) 4.30 *10^-3 molecules
C) 2.59 * 10²¹ molecules
D) 9.26 * 10²³ molecules
E) 5.92 *10²⁵ molecules

Question 38

Calculate the volume, in cm³, of 0.67 mol of acetone, C₃H₆O. The density of acetone is 0.791 g/cm³.

A) 49.1 cm³
B) 68.6 cm³
C) 110. cm³
D) 30.8 cm³
E) 0.0146 cm³

Question 39

Calculate the number of molecules contained in 1.43 moles of carbon monoxide (CO).

A) 40 molecules
B) 8.61 * 10²³ molecules
C) 3.07 *10²² molecules
D) 2.41 * 10²⁵ molecules
E) 4.21 * 10²³ molecules

Question 40

Calculate the mass, in grams, of 1.78*10²⁵ formula units of calcium nitrate.

A) 1.82 *10²⁷ g
B) 3.02* 10³ g
C) 1.08 * 10²³ g
D) 4.85 *10³ g
E) 29.6 g

Question 41

Ethane (C₂H₆) is a minor component of natural gas. How much carbon dioxide (in grams) is produced from the complete combustion of 42.0 g ethane?
2 C₂H₆ + 7 O₂ $\rightarrow$ 4 CO₂ + 6 H₂O

A) 123 g CO₂
B) 2.80 g CO₂
C) 61.6 g CO₂
D) 30.8 g CO₂
E) 28.6 g CO₂

Question 42

Ethane (C₂H₆) is a minor component of natural gas. How much oxygen (in grams) would be needed to react with 144 g ethane?
2 C₂H₆ + 7 O₂ $\rightarrow$ 4 CO₂ + 6 H₂O

A) 154 g
B) 536 g
C) 1080 g
D) 269 g
E) 422 g

Question 43

Joseph Priestley's discovery of oxygen involved the unbalanced chemical reaction provided here. What mass of oxygen would be produced from the decomposition of 12.3 g of HgO?
HgO $\rightarrow$ Hg + O₂

A) 1.82 g
B) 0.909 g
C) 3.63 g
D) 0.455 g
E) 0.981 g

Question 44

Joseph Priestley's discovery of oxygen involved the unbalanced chemical reaction provided here. What mass of mercury would be produced from the decomposition of 12.3 g of HgO?
HgO $\rightarrow$ Hg + O₂

A) 12.3 g
B) 11.4 g
C) 5.70 g
D) 22.8 g
E) 201 g

Question 45

Ammonia reacts with oxygen to produce nitric acid and water, according to the unbalanced equation provided here. How much nitric acid (in g) could be produced from reaction of 665 g ammonia?
NH₃ + O₂ $\rightarrow$ HNO₃ + H₂O

A) 63.0 g
B) 20 950 g
C) 4930 g
D) 1230 g
E) 2460 g

Question 46

Ammonia reacts with oxygen to produce nitric acid and water, according to the unbalanced equation provided here. How much oxygen (in g) would be required to produce 445 g nitric acid?
NH₃ + O₂ $\rightarrow$ HNO₃ + H₂O

A) 28 500 g
B) 904 g
C) 452 g
D) 226 g
E) 14.1 g

Question 47

The capacity to do work is known as

A) energy.
B) power.
C) potential.
D) thermicity.
E) velocity.

Question 48

The international unit for energy is the

A) watt.
B) volt.
C) joule.
D) tesla.
E) faraday.

Question 49

Choose the true statement.

A) Formation of covalent bonds absorbs energy.
B) Single bonds have lower bond energy than double bonds.
C) Breaking bonds is an exothermic process.
D) The units of bond energy are N/kg.
E) The higher the bond energy is, the easier it is to break.

Question 50

Calculate the energy change associated with the chemical reaction provided here. State whether it is endothermic or exothermic. [Bond energies (kJ/mol): H-H: 436; N-H: 391; NΞN 945]
N₂ + 3 H₂ $\rightarrow$ 2 NH₃

A) +93.0 kJ/mol, exothermic
B) 1080 kJ/mol, endothermic
C) -1080 kJ/mol, exothermic
D) -93.0 kJ/mol, exothermic
E) -93.0 kJ/mol, endothermic

Question 51

The cells in our body extract energy from carbohydrates like glucose through a process called

A) cellular respiration.
B) combustion.
C) exercise.
D) cellular decomposition.
E) cellular replication.

Question 52

Cells store chemical energy in the form of

A) DNA.
B) RNA.
C) ATP.
D) ADP.
E) AGT.

Question 53

Adenosine triphosphate (ATP) releases its chemical energy through a reaction that breaks off a(n)

A) oxygen molecule.
B) adenosine molecule.
C) carbon dioxide molecule.
D) phosphate group.
E) radical species.

Question 54

When initial ATP reserves are used up, the body can obtain additional ATP through a process called _______________ fermentation.

A) lactose
B) acetic acid
C) ethanol
D) cellular
E) lactic acid

Question 55

"Anaerobic" means without

A) life.
B) exercise.
C) carbon.
D) air.
E) energy.

Question 56

Solid aluminium reacts with oxygen gas to form solid aluminium oxide (Al₂O₃). Write the full, balanced chemical equation for this process.

Question 57

Calcium metal reacts with water to form solid calcium hydroxide and hydrogen gas. Write the full, balanced chemical equation for this process.

Question 58

What is the combining ratio of ethanol to oxygen when they react to form the products carbon dioxide and water?

Question 59

What is the combining ratio of ethanol to oxygen when they react to form the products carbon monoxide and water?

Question 60

A(n) ___________________ thermic reaction releases energy to the outside environment, while a(n) ___________________ thermic reaction absorbs energy from its surroundings.

Question 61

During a chemical reaction, bonds in the reactants are ___________________ (broken/formed) and ___________________ (release/absorb) energy, while bonds in the products are ____________________ (broken/formed) and ___________________ (release/absorb) energy.

Question 62

Combustion reactions tend to ___________________ (release/absorb) heat energy.

Question 63

Balance and calculate the energy change associated with the following chemical reaction. State whether it is endo- or exothermic. [Bond energies (kJ/mol): N-O 201; N=O 607; N-H 391; O-O 146; O=O 498; O-H 467]
__NH₃ + __O₂ $\rightarrow$ __NO + __H₂O