Question 1

What is the main difficulty in trying to eliminate chlorinated fluorocarbons from the atmosphere?

Accepted Answer

A)   They are very stable and take a long time to decompose completely.
B)   They are too light and blow away.
C)   They do not absorb ultraviolet radiation.
D)   all of the above
E)   only a and bF) B) and E)
G) D) and E)

Question 2

If it takes 20 beryllium atoms to equal the mass of two krypton atoms, what is the relative mass of beryllium compared to krypton?

Accepted Answer

A)   1/10
B)   1/20
C)   40 times
D)   100 times
E)   10 timesF) C) and D)
G) A) and E)

Question 3

What is the mass of an oxygen atom, O, in atomic mass units?

Accepted Answer

A)   12 amu
B)   16 amu
C)   18 amu
D)   32 amuE) B) and C)
F) C) and D)

Question 4

The chlorinated fluorocarbons molecules are acting as a(n)  ________ by converting hundreds of thousands of molecules before they are inactivated.

Accepted Answer

A)   catalyst
B)   aerosol
C)   active site
D)   acid
E)   baseF) B) and D)
G) A) and E)

Question 5

What are the formula masses of water,  O; propene,   ; and 2-propanol,   O?

Accepted Answer

A)   water: 18 amu; propene: 40 amu; 2-propanol: 58 amu
B)   water: 18 amu; propene: 42 amu; 2-propanol: 62 amu
C)   water: 18 amu; propene: 42 amu; 2-propanol: 60 amu
D)   water: 18 amu; propene: 44 amu; 2-propanol: 64 amuE) A) and D)
F) B) and C)

Question 6

How is Avogadro's number related to the numbers on the periodic table?

Accepted Answer

A)   The atomic mass listed is the mass of Avogadro's number's worth of atoms.
B)   The masses are all divisible by Avogadro's number, which gives you the weight of one mole.
C)   The periodic table tells you the mass of one atom. From that, and Avogadro's number you know the number of moles.
D)   The periodic table only gives us atomic numbers, not atomic mass.
E)   The mass listed is Avogadro's number.F) A) and E)
G) B) and C)

Question 7

What is the environmentally unfriendly component of chlorinated fluorocarbons that ultimately damages ozone?

Accepted Answer

A)   chlorine atoms
B)   fluorine atoms
C)   carbon atoms
D)   molecular fragments of carbon and fluorine
E)   all of the aboveF) B) and C)
G) None of the above

Question 8

Which has more atoms: 64.058 g of sulfur dioxide, S  (64.058 amu) , or 72.922 g of hydrogen chloride, HCl (36.461 amu) ?

Accepted Answer

A)   64.058 g of S  has more atoms than 72.922 g of HCl
B)   72.922 g of HCl has more atoms than 64.058 g of S 
C)   72.922 g of HCl and 64.058 g of S  have about the same number atoms.
D)   Not enough information is given.E) None of the above
F) A) and D)

Question 9

The atomic masses appearing in the periodic table are ________.

Accepted Answer

A)   absolute masses
B)   relative masses
C)   standard deviation masses
D)   formula massesE) A) and D)
F) B) and C)

Question 10

Which of the following has the greatest mass?

Accepted Answer

A)   1 mole of Pb
B)   1 mole of H2
C)   1 mole of Be
D)   1 mole of Na
E)   All have the same mass.F) A) and D)
G) A) and C)

Question 11

What is the number of moles of H2O produced if you combust 0.5 mole of CH4 according to the following balanced equation? CH4 + 2 O2 → CO2 + 2 H2O

Accepted Answer

A)   2 moles
B)   4 moles
C)   6 moles
D)   8 moles
E)   1 moleF) B) and C)
G) A) and E)

Question 12

Fourteen grams of nitrogen, N2, (N, atomic mass 14 amu)  contains ________.

Accepted Answer

A)   1 mole of nitrogen atoms
B)   0.5 moles of nitrogen atoms
C)   0.25 moles of nitrogen atoms
D)   Not enough information is givenE) A) and B)
F) A) and C)

Question 13

How many grams of water, H2O, can be produced from the reaction of 25.0 grams of hydrogen, H2, and 225 grams of oxygen, O2?

Accepted Answer

A)   250 grams
B)   225 grams
C)   200 grams
D)   25 gramsE) None of the above
F) C) and D)

Question 14

If it takes three carbon atoms to equal the mass of one chlorine atom, what mass of chlorine do you need to equal the number of atoms in one kilogram of carbon?

Accepted Answer

A)   1/3 of a kg
B)   30 kg
C)   1 kg
D)   3 kg
E)   6 kgF) None of the above
G) A) and B)

Question 15

You are given two samples of elements, and each sample has a mass of 10 grams. If the number of atoms in each of these samples is the same, what must be true of the two elements?

Accepted Answer

A)   The density of the two elements are the same.
B)   The elements are likely be located in the same position in the periodic table.
C)   Their spectral patterns will likely be identical.
D)   all of the aboveE) C) and D)
F) B) and D)

Question 16

For the following balanced equation, which has the highest coefficient? 4 H2 + 2 C → 2 CH4

Accepted Answer

A)   H2
B)   C
C)   CH4
D)   H4
E)   none of the aboveF) All of the above
G) A) and B)

Question 17

What is an endothermic reaction?

Accepted Answer

A)   It is a reaction that requires heat as a reactant.
B)   It is a reaction where the products have more energy than the reactants.
C)   It is a reaction where there is a net adsorption of energy from a reaction.
D)   all of the above
E)   none of the aboveF) A) and B)
G) B) and C)

Question 18

Given that the above energy profiles have the same scale, which of the reactions would require the most energy?

Accepted Answer

A)   a
B)   b
C)   c
D)   d
E)   none of the aboveF) A) and E)
G) B) and D)

Question 19

Which of the following has the greatest number of particles?

Accepted Answer

A)   1 mole of Na
B)   22.990 g of Na
C)   1 mole of Be
D)   9.012 g of Be
E)   All are the same.F) A) and E)
G) A) and B)

Question 20

How many moles of H2 bonds are broken if you react nitrogen with hydrogen according to the following reaction? N2 + 3H2 → 2 NH3

Accepted Answer

A)   6
B)   2
C)   3
D)   1
E)   8F) A) and B)
G) A) and C)

Exam 9: How Chemicals React

What is the mass of an oxygen atom, O, in atomic mass units?

Correct AnswerverifiedShow Answer

What is an endothermic reaction?

Correct AnswerverifiedShow Answer

The chlorinated fluorocarbons molecules are acting as a(n) ________ by converting hundreds of thousands of molecules before they are inactivated.

Correct AnswerverifiedShow Answer

What are the formula masses of water, O; propene, ; and 2-propanol, O?

Correct AnswerverifiedShow Answer

Which of the following has the greatest mass?

Correct AnswerverifiedShow Answer

Given that the above energy profiles have the same scale, which of the reactions would require the most energy?

Correct AnswerverifiedShow Answer

If it takes 20 beryllium atoms to equal the mass of two krypton atoms, what is the relative mass of beryllium compared to krypton?

Correct AnswerverifiedShow Answer

How is Avogadro's number related to the numbers on the periodic table?

Correct AnswerverifiedShow Answer

How many grams of water, H2O, can be produced from the reaction of 25.0 grams of hydrogen, H2, and 225 grams of oxygen, O2?

Correct AnswerverifiedShow Answer

How many moles of H2 bonds are broken if you react nitrogen with hydrogen according to the following reaction? N2 + 3H2 → 2 NH3

Correct AnswerverifiedShow Answer

For the following balanced equation, which has the highest coefficient? 4 H2 + 2 C → 2 CH4

Correct AnswerverifiedShow Answer

Which has more atoms: 64.058 g of sulfur dioxide, S (64.058 amu) , or 72.922 g of hydrogen chloride, HCl (36.461 amu) ?

Correct AnswerverifiedShow Answer

Which of the following has the greatest number of particles?

Correct AnswerverifiedShow Answer

If it takes three carbon atoms to equal the mass of one chlorine atom, what mass of chlorine do you need to equal the number of atoms in one kilogram of carbon?

Correct AnswerverifiedShow Answer

You are given two samples of elements, and each sample has a mass of 10 grams. If the number of atoms in each of these samples is the same, what must be true of the two elements?

Correct AnswerverifiedShow Answer

The atomic masses appearing in the periodic table are ________.

Correct AnswerverifiedShow Answer

Fourteen grams of nitrogen, N2, (N, atomic mass 14 amu) contains ________.

Correct AnswerverifiedShow Answer

What is the number of moles of H2O produced if you combust 0.5 mole of CH4 according to the following balanced equation? CH4 + 2 O2 → CO2 + 2 H2O

Correct AnswerverifiedShow Answer

What is the environmentally unfriendly component of chlorinated fluorocarbons that ultimately damages ozone?

Correct AnswerverifiedShow Answer

What is the main difficulty in trying to eliminate chlorinated fluorocarbons from the atmosphere?

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

How many grams of water, H₂O, can be produced from the reaction of 25.0 grams of hydrogen, H₂, and 225 grams of oxygen, O₂?

Correct Answer
verified

How many moles of H₂ bonds are broken if you react nitrogen with hydrogen according to the following reaction? N₂+ 3H₂ → 2 NH₃

Correct Answer
verified

For the following balanced equation, which has the highest coefficient? 4 H₂ + 2 C → 2 CH₄

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Fourteen grams of nitrogen, N₂, (N, atomic mass 14 amu) contains ________.

Correct Answer
verified

What is the number of moles of H₂O produced if you combust 0.5 mole of CH₄ according to the following balanced equation? CH₄ + 2 O₂ → CO₂ + 2 H₂O

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified