Quiz
Exam 3
Questions in this quiz (92)
1What is the activation energy?
- Athe energy difference between the reactants and the products
- Bthe amount of energy required to activate a phase change
- Cthe amount of energy required to separate reactants from the products
- Dthe minimum amount of energy in order to transform into product molecules
- Ethe hill
2Why might increasing the concentration of a set of reactants increase the rate of reaction?
- AYou have increased the ratio of reactants to products.
- BThe rate of reaction depends only on the mass of the atoms and therefore increases as you increase the mass of the reactants.
- CThe concentration of reactants is unrelated to the rate of reaction.
- DYou have increased the chances that any two reactant molecules will collide and react.
- Enone of the above
3What is the formula mass of a molecule of C6H12O6?
- A180 amu
- B24 amu
- C168 amu
- D29 amu
- Enone of the above
4If it takes 200 golf balls to equal the mass of four bowling balls, what is the relative mass of bowling balls to golf balls?
- A20 times
- B1/20
- C100 times
- D6.022 × 1023
- E1/50
5Given the following generic chemical reaction, which is the product?
X → Y- A→ is the product.
- BX is the product.
- CY is the product.
- DBoth X and Y are the products.
- EBoth X and Y are the reactants.
6Which of the following reaction energies is the most endothermic?
- A-540 kJ/mole
- B540 kJ/mole
- C125 kj/mole
- D-125 kJ/mole
- Enot enough information given
7Use the bond energies below to determine whether the following reaction is exothermic or endothermic:
H2 + Cl2 → 2 HCl
H-H (bond energy: 436 kJ/mol)
Cl-Cl (bond energy: 243 kJ/mol)
H-Cl (bond energy: 431 kJ/mol)- AExothermic with more than 50 kJ of energy released.
- BEndothermic with more than 50 kJ of energy absorbed.
- CEndothermic with less than 50 kJ of energy absorbed.
- DExothermic with less than 50 kJ of energy released.
8What is an exothermic reaction?
- AIt is a reaction where there is a net adsorption of energy from a reaction.
- BIt is a reaction where the products have more energy than the reactants.
- CIt is a reaction that requires heat as a reactant.
- Dall of the above
- Enone of the above
9Which of the following is a correctly balanced equation?
- A2 P4 + 12 H2 → 8 PH3
- B0 P4 + 6 H2 → 4 PH3
- CP4 + 3 H2 → PH3
- DP4 + 6 H2 → 4 PH3
- E1 P4 + 6 H2 → 4 PH3
10For the following balanced reaction, which of the following is a solid?
2 Na(l) + Cl2(g) → 2 NaCl(s)- ANaCl
- BCl
- CNa
- DCl2
- E2 Na
11What is the mass of an oxygen atom, O, in atomic mass units?
- A16 amu
- B12 amu
- C18 amu
- D32 amu
12How does a catalyst increase the rate of a reaction?
- AIt increases the energy difference between the reactants and products.
- BIt is neither created nor consumed in a reaction.
- CIt raises the activation energy of the reactants, which makes the reaction proceed faster.
- DIt has nothing to do with the rate of reaction.
- EIt lowers the activation energy.
13Which of the following statements best describes the concept of entropy?
- AEnergy has a tendency to remain in one place.
- BThe energy released in a chemical reaction is the same as the difference in the energy of the bonds broken and formed.
- CThe entropy of the universe is constantly decreasing.
- DEnergy has a tendency to disperse.
- EEnergy is neither created nor destroyed.
14For the following balanced reaction, which of the following is a gas?
2 Na(l) + Cl2(g) → 2 NaCl(s)- A2 Na
- BNa
- CCl
- DNaCl
- ECl2
15If it takes energy to break bonds and you gain energy in the formation of bonds, how can some reactions be exothermic while others are endothermic?
- ASome products have more energy than others and they always require energy to be formed.
- BSome reactants have more energetic bonds than others and they will always release energy.
- CIt is the total amount of energy that matters. Sometimes some bonds are stronger than others and so you gain or lose energy when you form them.
- DIt is the total number of bonds that matters. Sometimes you create more bonds than you break and since all bonds have same amount of energy you gain or lose energy depending on the number of bonds.
- Enone of the above
16Given the following generic chemical reaction, which is the reactant?
X → Y- A→ is the reactant.
- BX is the reactant.
- CY is the reactant.
- DBoth X and Y are the products.
- EBoth X and Y are the reactants.
17What is a chemical reaction?
- Awhen two solids mix together to form a heterogeneous mixture
- Bwhen two liquids mix to form a homogeneous mixture
- Cwhen a liquid undergoes a phase change and produces a solid
- Dwhen one or more new compounds are formed by rearranging atoms
- Ewhen a new element is formed by rearranging nucleons
18Which is higher in an endothermic reaction: the potential energy of the reactants or the potential energy of the products?
- AThe potential energy of the reactants is higher than the potential energy of the products.
- BThe potential energy of the products is higher than the potential energy of the reactants.
- CIn the early stages of the reaction the potential energy of the reactants is higher. In the later stages, the potential energy of the products is higher.
- DThe potential energy of the reactants is the same as the potential energy of the products.
19What are the formula masses of water, H2O; propene, C3H6; and 2-propanol, C3H8O?
- Awater: 18 amu; propene: 44 amu; 2-propanol: 64 amu
- Bwater: 18 amu; propene: 40 amu; 2-propanol: 58 amu
- Cwater: 18 amu; propene: 42 amu; 2-propanol: 60 amu
- Dwater: 18 amu; propene: 42 amu; 2-propanol: 62 amu
20What is a reaction rate?
- AIt is the speed with which products form from the reactants
- BIt is the ratio of the molecular masses of the elements in a given compound.
- CIt is the balanced chemical formula that relates the number of product molecules to reactant molecules.
- DIt is the ratio of the masses of products and reactants.
- Enone of the above
21What is the mass of a water molecule, H2O, in atomic mass units?
- A3 amu
- B18 amu
- C2 amu
- D16 amu
22According to the following balanced chemical equation, if you want to generate two moles of H2O, how many moles of O2 do you need?
2 H2 + O2 → 2 H2O- A2
- B1
- C6.022 × 1023
- D1/2
- E4
23Why is it important for a chemist to know the relative masses of atoms?
- AThere are not that many different kinds of atoms and so it's important to know how they relate to one another.
- BIt provides information about how many atoms two samples have relative to each other
- CBecause the mass of an atom is directly related to its chemical properties.
- DIt provides an indication of how the different atoms will interact
24What is an endothermic reaction?
- AIt is a reaction that requires heat as a reactant.
- BIt is a reaction where there is a net adsorption of energy from a reaction.
- CIt is a reaction where the products have more energy than the reactant
- Dall of the above
- Enone of the above
25For the following balanced equation, which has the highest coefficient?
4 H2 + 2 C → 2 CH4- AH2
- BH4
- CCH4
- DC
- Enone of the above
26Which of the following materials is most likely to undergo reduction?
- ACl-
- BNa+
- CCl2
- DNa
- Eboth A and B
27For the following acid-base reaction, identify what compound is formed in the space marked.
HNO3 + KOH ⇌ ???? + H2O- AKNO3
- BKOH2
- CH3ONO3
- DKOH2NO3
- Enone of the above
28For each of the following unbalanced equations, which is depicted: oxidation or reduction?
a) Cr → Cr3+ b) Sn → Sn(OH)42-- Aa) reduction; b) oxidation
- Ba) reduction; b) reduction
- Ca) oxidation; b) reduction
- Da) oxidation; b) oxidation
29Which of the following solutions is the most acidic?
- Aa solution with a pH = 10
- Ba solution with a pH = 14
- Ca solution with a pH = 7
- Da solution with a pH = 4
- EAll of the solutions are basic.
30Which of the following statements describes a basic solution?
- A[H3O+] [OH-]
- B[H3O+] × [OH-] ≠ 1 × 10-14
- C[H3O+]/[OH-] = 1
- D[H3O+] > [OH-]
- E[H3O+]/[OH-] = 1 × 10-14
31What is a base?
- AAnything with a bitter taste.
- BAnything that can be used to clean drains.
- CAnything that accepts a hydroxide ion.
- DAnything that accepts a hydrogen ion.
- EAnything that donates a hydroxide ion.
32For the following reaction, identify whether the compound in bold is behaving as an acid or a base.
H3PO4 + H2O ⇌ H2PO4- + H3O+- Aacid
- Bbase
- Cneither
- Dboth
- Enone of the above
33For the following reaction, identify whether the compound in bold is behaving as an acid or a base.
H3PO4 + H2O ⇌ H2PO4- + H3O+- Aacid
- Bbase
- Cneither
- Dboth
- Enone of the above
34According to the following reaction, which molecule is acting as an acid?
H3O+ + HSO4- → H2O + H2SO4- AH2SO4
- BHSO4-
- CH2O
- DH3O+
- Enone of the above
35What is an acid?
- AAnything that accepts hydrogen atoms.
- BAnything that donates hydrogen atoms.
- CAnything that donates hydrogen ions.
- DAnything that dissolves metal.
- EAnything that donates hydronium ions.
36How many electrons are gained or lost in the following half-reaction?
Na → Na+- A1/2 electron is gained
- B2 electrons are gained
- C1 electron is lost
- D1/2 electron is lost
- E1 electron is gained
37What is a reduction?
- Athe formation of red compounds in the presence of an oxidant
- Bthe gain of electrons
- Cthe reaction of oxygen with a reductant
- Dthe loss of an electron from the valence shell
- Ethe reduction of the number of electrons
38What is oxidation?
- Athe reduction of oxygen
- Bthe loss of electrons
- Cthe addition of an electron to the valence shell
- Dthe gaining of electrons
- Ethe reaction with oxygen
39How is electrolysis different from what is going on chemically inside a battery?
- AYou cannot make pure compounds with electrolysis.
- BElectrolysis does not use electrons.
- CYou do not produce a chemical change in electrolysis.
- DThey are the same process, just reversed.
- EElectrolysis only uses electrons from a cathode.
40An acid and a base react to form a salt, which consists of positive and negative ions. Which forms the positive ions: the acid or the base? Which forms the negative ions?
- AThe acid forms the negative ion, the base forms the positive ion.
- BThe acid forms the positive ion, the base forms the negative ion.
- CBecause different substances can act as an acid or a base, it depends on the substance you begin with.
- Dall of the above
41According to the following reaction, which molecule is acting as a base?
H3O+ + HSO4- → H2O + H2SO4- AH2O
- BHSO4-
- CH2SO4
- DH3O+
- Enone of the above
42For the following reaction, identify whether the compound in bold is behaving as an acid or a base.
H3PO4 + H2O ⇌ H2PO4- + H3O+- Aacid
- Bbase
- Cneither
- Dboth
- Enone of the above
43Which of the following statements is not true about a neutralization reaction?
- AOne molecule of acid neutralizes one molecule of base.
- BA neutralization is the reaction of a hydroxide ion with a proton.
- CWater is always formed in a neutralization reaction.
- DAll of the above are true.
- ENone of the above are true.
44Which of the following statements describes a neutral solution?
- A[H3O+] > [OH-]
- B[H3O+] × [OH-] ≠ 1 × 10-14
- C[H3O+]/[OH-] = 1 × 10-14
- D[H3O+] [OH-]
- E[H3O+]/[OH-] = 1
45How many electrons are gained or lost in the following half-reaction?
Cl2 → 2 Cl-- A4 electrons are gained
- B2 electrons are lost
- C1/2 electron is lost
- D2 electrons are gained
- E1/2 electron is gained
46According to the following reaction, which molecule is acting as a base?
H2O + NH3 → OH- + NH4+- AH2O
- BNH4+
- COH-
- DNH3
- Enone of the above
47Which of the following statements about electrochemistry is not true?
- AIt involves the use of a set of oxidation-reduction reactions to produce electrical current.
- BIt is the study of how electrical energy and chemical reactions are related.
- CIt involves the use of electrical current to produce an oxidation-reduction reaction.
- DIt is the study of how electrons are transferred from one chemical compound to another.
- EAll of the above are true.
48What element is oxidized in the following equation and what element is reduced?
Sn2+ + 2 Ag → Sn + 2 Ag⁺- AThe tin ion, Sn2+, is oxidized, while the silver, Ag, is reduced.
- BBoth the tin ion, Sn2+, and the silver, Ag, are reduced.
- CBoth the tin ion, Sn2+, and the silver, Ag, are oxidized.
- DThe tin ion, Sn2+, is reduced, while the silver, Ag, is oxidized.
49According to the following reaction, which molecule is acting as a base?
OH- + NH4+ → H2O + NH3- AOH-
- BNH3
- CNH4+
- DH2O
- Enone of the above
50For the following acid-base reaction, identify what compound is formed in the space marked.
HCl + KOH ⇌ ???? + H2O- AH3OCl
- BKOH2Cl
- CKCl
- DKOH2
- Enone of the above
51What is the activation energy?
- Athe energy difference between the reactants and the products
- Bthe amount of energy required to activate a phase change
- Cthe amount of energy required to separate reactants from the products
- Dthe minimum amount of energy in order to transform into product molecules
- Ethe hill
52Is it possible to have a macroscopic sample of oxygen that has a mass of 14 atomic mass units?
- ANo, because oxygen is a gas at room temperature.
- BYes, but it would have the same density as nitrogen.
- CNo, this is less than than the mass of a single oxygen atom.
- DYes, but it would need to be made of oxygen atoms that each had less than the normal number of neutrons.
53Why might increasing the temperature alter the rate of a chemical reaction?
- AThe molecules will have a higher kinetic energy and bump into one another harder.
- BThe density decreases as a function of temperature and this leads to an increase in volume which drops the rate of reaction.
- CThe molecules are less reactive at higher temperatures.
- DThe molecules will more likely combine with other atoms at high temperature to save space.
- Enone of the above
54A refrigerator delays the spoilage of food by
- Adiminishing the supply of oxygen to microorganism
- Bslowing down the rate of chemical reactions within microorganisms.
- Cexpanding the water found within microorganisms.
- Dkilling microorganisms.
55The ________ is what needs to be overcome in a reaction so that it can proceed to the products.
- Acatalyst
- Bthermodynamics
- Cbond energy
- Dactivation energy
- Eentropy
56Which of the following statements about catalysts is NOT true?
- AA catalyst does not change the energy of the reactants or the products.
- BA catalyst can be used to speed up slow reactions.
- CA catalyst alters the rate of a chemical reaction.
- DA catalyst can be consumed in a reaction as long as it is regenerated.
- EAll of the above are true.
57What is the formula mass of sulfur dioxide, SO2?
- Aabout 32 amu
- Babout 60 amu
- Cabout 16 amu
- Dabout 64 amu
58What coefficient is needed in front of the O2 molecule to balance the following equation?
2 C4H10 (g) + _____ O2 (g) → 8CO2 (g) + 10 H2O (l)- A5
- B1
- C13
- D8
59How is Avogadro's number related to the numbers on the periodic table?
- AThe periodic table tells you the mass of one atom. From that, and Avogadro's number you know the number of moles.
- BThe mass listed is Avogadro's number.
- CThe masses are all divisible by Avogadro's number, which gives you the weight of one mole.
- DThe periodic table only gives us atomic numbers, not atomic mass.
- EThe atomic mass listed is the mass of Avogadro's number's worth of atoms.
60What is wrong with the following depiction of a chemical reaction?
- AOne box contains more atoms than the other.
- BOne box contains more molecules than the other.
- CThese boxes contain only molecules but no atoms.
- DAll of the above.
61What is the mass of one mole of H2?
- A6.022 × 1023 g
- B1 g
- C20 g
- D2 g
- Enone of the above
62Why is heat often added to chemical reactions performed in the laboratory?
- Ato increase the rate at which reactant collide
- Bto compensate for the natural tendency of energy to disperse
- Cto allow a greater number of reactants to pass over the activation energy
- Dall of the above
63Which equations are balanced?
a) Mg (s) + 2HCl (aq) → MgCl2 (aq) + H2 (g)
b) 3Al (s) + 3 Br2 (l) → Al2Br3 (s)
c) 2HgO (s) → 2 Hg (l) + O2 (g)- AOnly equation "c" is balanced.
- BEquations "b" and "c" are balanced.
- CEquations "a" and "c" are balanced.
- DAll of them are balanced.
64According to the following balanced chemical equation, if you want to generate two moles of H2O how many grams of O2 do you need?
2 H2 + O2 → 2 H2O- A32
- B4
- C8
- D16
- E6.022 × 1023
65How does formula mass differ from atomic mass?
- AThe atomic mass of a substance is the sum of the formula masses of the elements is its chemical formula. The atomic mass is the mass of a single atom.
- BThe formula mass is the mass of the chemical formula and the atomic mass is the mass of the molecule.
- CThey represent the same thing.
- DThe formula mass of a substance is the sum of the atomic masses of the elements is its chemical formula. The atomic mass is the mass of a single atom.
66Which of the following has the greatest number of particles?
- A1 mole of Be
- B1 mole of Na
- C9.012 g of Be
- D22.990 g of Na
- EAll are the same.
67For the following reaction, identify whether the compound in bold is behaving as an acid or a base.
H3PO4 + H2O ⇌ H2PO4- + H3O+- Aacid
- Bbase
- Cneither
- Dboth
- Enone of the above
68Which of the following statements describes an acidic solution?
- A[H3O+]/[OH-] = 1
- B[H3O+] > [OH-]
- C[H3O+]/[OH-] = 1 × 10-14
- D[H3O+] [OH-]
- E[H3O+] × [OH-] ≠ 1 × 10-14
69How many electrons are gained or lost in the following half-reaction?
2 Na → 2 Na+- A4 electrons are gained
- B1/2 electron is lost
- C1/2 electron is gained
- D2 electrons are lost
- E2 electrons are gained
70Which of the following statements is untrue about oxidation and reduction processes?
- AOften ions are generated or consumed.
- BAn oxidation can happen without a reduction.
- CIt involves the exchange of electrons.
- DElectrons are often involved in oxidation and reduction reactions.
- EAll of the above are true.
71Which of the following statements about oxidation and reduction reactions is true?
- AOnly neutral atoms are formed in oxidation and reduction reactions.
- BMore than one electron can be transferred in an oxidation and reduction reaction.
- CA half-reaction is only used for reduction reactions.
- DIn a half-reaction, only half of an electron is transferred.
- ENone of the above are true.
72How many electrons are gained or lost in the following half-reaction?
Zn → Zn+2- A2 electrons are lost
- B1/2 electron is gained
- C4 electrons are gained
- D2 electrons are gained
- E1/2 electron is lost
73According to the following reaction, which molecule is acting as an acid?
OH- + NH4+ → H2O + NH3- AH2O
- BOH-
- CNH4+
- DNH3
- Enone of the above
74Which of the following compounds would least likely act as an acid?
- AHSO4-1
- BSO4-2
- CH2SO4
- DCH3CO2H
- ENH3
75In the reaction below, what does the symbol ⇌ mean?
OH- + NH4+ ⇌ H2O + NH3- AIt means that the backward reaction happens as fast as the forward reaction and so the proton is not transferred at all.
- BIt means that the forward and backward reactions are happening at the same time.
- CIt means that the forward reaction does not progress.
- DIt means that the reaction cannot decide which way to go.
- Enone of the above
76According to the following reaction, which molecule is acting as an acid?
H2O + NH3 → OH- + NH4+- ANH4+
- BH2O
- CNH3
- DOH-
- Enone of the above
77Qualitatively, what happens to the hydroxide ion concentration if you decrease the hydronium ion concentration?
- AThe concentration of OH- increases.
- BThe concentration of OH- stays the same but the ratio OH-/H3O+ changes.
- CThe concentration of OH- increases but the ratio stays the same.
- Dnone of the above
78How do you make a proton out of a hydrogen atom?
- Aremove a proton from a helium nucleus
- Blet the hydrogen atoms undergo fusion
- Clet the hydrogen atoms combine to form a hydrogen molecule and eject a proton
- Dremove an electron from a hydrogen atom
- Elet the hydrogen atoms combine to form a hydrogen molecule and eject an electron
79What is the formula mass of a molecule of CO2?
- A118 amu
- B56 amu
- C44 amu
- D58.9 amu
- Enone of the above
80Some reactions are more sluggish than others. To speed up these reactions and save energy a(n) ________ is sometimes added.
- Aheat source
- Bactivator
- Creaction profile
- Dcatalyst
- Eexotherm
81Given the following generic chemical reaction, which is the product?
X → Y- A→ is the product.
- BX is the product.
- CY is the product.
- DBoth X and Y are the products.
- EBoth X and Y are the reactants.
82Which of the following reaction energies is the least exothermic (but still an exothermic reaction)?
- A-125 kJ/mole
- B540 kJ/mole
- C125 kJ/mole
- D-540 kJ/mole
- Enot enough information given
83What is a chemical equation?
- AIt is the sum of the masses of the products and reactants.
- BIt is any type of reaction that takes place at the equator.
- CIt is a picture of the atoms undergoing a chemical equalization.
- DIt is the chemical combination of equal numbers of reactants and products.
- EIt is a shorthand notation for illustrating a chemical reaction.
84Balance the following equation.
____ NO → ____ N2O + _____ NO2- A3, 0, 0
- B1, 2, 4
- C3, 1, 1
- D4, 4, 8
- E6, 2, 1
85According to the following balanced chemical equation, if you want to generate two moles of H2O , how many molecules of O2 do you need?
2 H2 + O2 → 2 H2O- A2
- B1
- C1/2
- D4
- E6.022 × 10^23
86According to the following reaction, which molecule is acting as an acid?
H2O + NH3 → OH- + NH4+- ANH4+
- BH2O
- CNH3
- DOH-
- Enone of the above
87Which of the following solutions is the most acidic?
- Aa solution with a pH = 7
- Ba solution with a pH = 14
- Ca solution with a pH = 13
- Da solution with a pH = 12
- EAll of the solutions are basic.
88How many electrons are gained or lost in the following half-reaction?
Cl2 → 2 Cl-- A4 electrons are gained
- B2 electrons are lost
- C1/2 electron is lost
- D2 electrons are gained
- E1/2 electron is gained
89For the following acid-base reaction, identify what is formed in the space marked.
HF + KOH ⇌ ???? + H2O- AH3OF
- BKOH2
- CKF
- DKOH2F
- Enone of the above
90As the pH increases, the hydroxide ion concentration ________.
- Agets larger
- Bgoes down
- Cstays constant
- Dstarts to decrease because it is reacting with the excess hydronium ions
- Estarts to affect the H+ concentration
91According to the following reaction, which molecule is acting as an acid?
H2O + H2SO4 → H3O+ + HSO4-- AH3O+
- BH2SO4
- CH2O
- DHSO4-
- Enone of the above
92According to the following reaction, which molecule is acting as a base?
H3O+ + HSO4- → H2O + H2SO4- AH2O
- BHSO4-
- CH2SO4
- DH3O+
- Enone of the above
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- Physics
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- Kimberly Lopez
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- Created on 26 Nov 2016 · updated on 3 Dec 2016
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