Free Printable MIDTERM EXAM

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MIDTERM EXAM

Total questions: 50

Worksheet time: 46mins

Name

Class

Date

The anode is where

electrolyte concentrations are lowest.

electrolyte concentrations are highest.

anions are produced.

oxidation occurs.

All of the following statements concerning voltaic cells are true EXCEPT

a salt bridge allows cations and anions to move between the half-cells.

electrons flow from the cathode to the anode in the external circuit.

oxidation occurs at the anode.

a voltaic cell consists of two-half cells.

The following reaction occurs spontaneously.

2 Fe(s) + 3 Cl₂(aq) --> 2 Fe³⁺(aq) + 6 Cl^–(aq)

Write the balanced reduction half-reaction

Fe(s) -> Fe³⁺(aq) + e^–

Fe(s) + 3 e^– -> Fe³⁺(aq)

Fe(s) + 3/2 Cl₂(aq) -> FeCl₃(aq)

Cl₂(aq) + 2 e^– -> 2 Cl^–(aq)

The following reaction occurs spontaneously.

2Al(s) + 6H⁺(aq) -> 2Al³⁺(aq) + 3H₂(g)

Write the balanced oxidation half-reaction

Al(s) -> Al³⁺(aq) + 3e^-

Al³⁺(aq) + 3e^- -> Al(s)

H₂(g) -> 2H⁺(aq) + 2e^-

2H⁺(aq) -> H₂(g) + 2e^-

Given the following half-reactions,

Pb(s) + 2I^-(aq) -> PbI₂(s) + 2e^-

I₂(aq) + 2e^- -> 2I^-(aq)

write the balanced overall reaction.

Pb(s) + I₂(aq) + 2e^- -> PbI (s) + I^-(aq)

Pb(s) + I₂(aq) -> PbI₂(s)

Pb(s) + Cl₂(aq) -> Pb²⁺(aq) + 2I^-(aq)

2Pb(s) + 4e^- -> 2PbI(s) + I₂(aq)

Given the following half-reactions

2IO₃^-(aq) + 12H⁺(aq) + 10e^- -> I₂(s) + 6H₂O(l)

Fe²⁺(aq) -> Fe³⁺(aq) + e^-

write the balanced overall reaction.

2IO₃^-(aq) + 10Fe²⁺(aq) -> I₂(s) + 10Fe³⁺(aq)

2IO₃^-(aq) + 12H⁺(aq) + Fe²⁺(aq) -> FeI₂(s) + 6H₂O(l)

2IO₃^-(aq) + 12H⁺(aq) + Fe²⁺(aq) -> I₂(s) + Fe³⁺(aq) + 6H₂O(l)

2IO₃^-(aq) + 12H⁺(aq) + 10Fe²⁺(aq) -> I₂(s) + 10Fe³⁺(aq) + 6H₂O(l)

Write a balanced net ionic equation for the overall reaction represented by the cell notation below.

Ag | AgI | I^– || Fe²⁺, Fe³⁺ | Pt

Fe³⁺(aq) + Ag(s) + I^–(aq) -> Fe²⁺(aq) + AgI(s)

Fe²⁺(aq) + Ag(s) + I^–(aq) -> Fe³⁺(aq) + AgI(s)

Fe³⁺(aq) + 2I^–(aq) -> Fe²⁺(aq) + I₂(s)

Fe²⁺(aq) + AgI(s) -> Fe³⁺(aq) + Ag(s) + I^–(aq)

What is the correct cell notation for the reaction below?

Cd²⁺(aq) + Ni(s) -> Cd(s) + Ni²⁺(aq)

Cd²⁺ | Cd || Ni | Ni²⁺

Cd | Cd²⁺ || Ni²⁺ | Ni

Ni | Ni²⁺ || Cd²⁺ | Cd

Cd²⁺ | Cd || Ni | Ni²⁺

10.

Write the overall chemical reaction and calculate E° for the following reduction and oxidation half-reactions.

Zn²⁺(aq) + H₂(g) -> Zn(s) + 2H⁺(aq) E° = +0.381 V

Zn²⁺(aq) + H₂(g) -> Zn(s) + 2H⁺(aq) E° = -0.762 V

Zn(s) + 2H⁺(aq) -> Zn²⁺(aq) + H₂(g) E° = +0.762 V

Zn(s) + 2H⁺(aq) -> Zn²⁺(aq) + H₂(g) E° = -0.381 V

11.

Given the following two half-reactions, write the overall balanced reaction in the direction in which it is spontaneous and calculate the standard cell potential.

2Ga³⁺(aq) + 3Sn²⁺(aq) -> 2Ga(s) + 3Sn⁴⁺(aq) E° = +0.68 V

3Ga³⁺(aq) + 2Sn²⁺(aq) -> 3Ga(s) + 2Sn⁴⁺(aq) E° = –1.89 V

2Ga(s) + 3Sn⁴⁺(aq) -> 2Ga³⁺(aq) + 3Sn²⁺(aq) E° = +0.68 V

2Ga(s) + 3Sn⁴⁺(aq) -> 2Ga³⁺(aq) + 3Sn²⁺(aq) E° = +1.89 V

12.

cathode is the electrode where

reduction takes place

oxidation takes place

either reduction or oxidation

none of these

13.

in electrochemical cell anode is

positive

negative

neutral

none

14.

Oxidation happens at the

Anode

Cathode

Salt bridge

Voltmeter

15.

Which is the correct oxidation half reaction for the reaction:
Al(s) + Zn(NO₃)₂(aq) → Al(NO₃)₃(aq) + Zn(s)

Al(s) + 3e- →Al³⁺ (aq)

Zn(s) → Zn²⁺(aq) + 2e^-

Al(s) → Al³⁺(aq) + 3e^-

Zn²⁺(aq) +2e^- →Zn(s)

16.

How is the alpha particle written in a nuclear equation?

^{(1) 4}₂He

^{(2) 2}₄He

^{(3) 0}_-1e

^{(4) 0}₀γ

17.

Which type of nuclear radiation is being emitted here?

Alpha

beta

gamma

none

18.

Solve this equation for alpha decay.
₈₅²⁰⁹At = ___ + ₂⁴He

_{(option 1)}

₈₃²⁰⁵Bi

_{(option 2)}

₈₆²⁰⁹Rn

_(option3)

₈₁²⁰⁷Tl

_{(option 4)}

₈₅²⁰⁸At

19.

Solve this equation for beta decay.
₆¹⁴C = ___ + _-1⁰e

_{(option 1)}

₄¹⁰Be

_{(option 2)}

₇¹⁴N

_{(option 3)}

₂¹⁰He

_{(option 4)}

₆¹³C

20.

Has the highest penetrating power. Can penetrate our body. Even several cm thick of lead or several meters thick of concrete cannot stop all of it.

Alpha

Beta

Gamma

21.

Has the lowest penetrating power. Can only penetrate 0.05 mm into the body and can be stopped by the skin.

Alpha

Beta

Gamma

Electron capture

22.

Uranium-238 decays into Thorium-234 by emitting .........

an alpha particle

a beta particle

gamma rays

visible light

23.

In a correctly written symbol what would be located in the "A" position?

number of neutrons

atomic number

number of electrons

mass number

24.

What is the correct # of protons, electrons, and neutrons for Cobalt - 59?

27 protons, 59 electrons, & 27 neutrons

59 protons, 59 electrons, & 86 neutrons

27 protons, 27 electrons, & 32 neutrons

27 protons, 32 electrons, & 27 neutrons

25.

What is an isotope?

Atoms of the same element with different masses.

Atoms of the same element with different # of protons.

Atoms of the same element with different atomic numbers.

Atoms of the same element with the different # of electrons.

26.

Balance the following equation:
¹⁴₆C --> ⁰_-1e + ________

^{(option 1)}

¹⁴₅B

^{(option 2)}

¹⁴₆C

^{(option 3)}

¹⁴₇N

^{(option 4)}

⁴₂He

27.

In the symbol ¹⁶₇N what the 7 stand for?

Mass number

Atomic number

Atomic mass

Number of neutrons

28.

If an atom of Americium-231 (Am) goes through alpha decay, what would you have at the end?

Neptunium-227

Neptunium-234

Plutonium-231

Curium-247

29.

If an atom of potassium-40 (K) goes through gamma decay, what would you have at the end?

Potassium-40

Calcium-40

Argon-35

Potassium-39

30.

Radioactive materials have unstable...

electrons

protons

nuclei

neutrons

31.

Complete the following nuclear decay reaction

^{(option 1)}

²¹⁷₈₆Rn

^{(option 2)}

²¹⁷₈₈Ra

^{(option 3)}

²¹⁷₉₂U

^{(option 4)}

²²⁵₈₆Rn

32.

What nucleus decays by beta emission to produce antimony-121?

^{(option 1)}

¹²⁰₅₀Sn

^{(option 2)}

¹²²₅₁Sb

^{(option 3)}

¹²¹₅₀Sn

^{(option 4)}

¹²⁵₅₃I

33.

What element is produced by the alpha decay of ²¹⁰₈₃Bi?

^{(option 1)}

²¹⁰₈₁Tl

^{(option 2)}

²⁰⁸_⁷⁹Au

^{(option 3)}

²⁰⁶_⁸¹Tl

^{(option 4)}

²⁰⁶₈₁Bi

34.

The name for protons and neutrons in nuclear chemistry is____

beta particles

positrons

nucleons

nuclides

35.

What is the equation for the positron emission by oxygen-16?

^{(option 1)}

¹⁶₈O + ⁰₊₁e --> ¹⁶₉F

^{(option 2)}

¹⁶₈O --> ⁴₂He + ¹²₆C

^{(option 3)}

¹⁶₈O --> ⁰_-1e + ¹⁶₉F

^{(option 4)}

¹⁶₈O --> ⁰₊₁e + ¹⁶₇N

36.

What is Combustion?

reaction between substance (fuel, wood, paper clothes etc) and oxygen that releases Carbon dioxide and Water, with lots of energy.

reaction between substance (fuel, wood, paper clothes etc) and carbon dioxide that releases oxygen and Water, with lots of energy.

reaction between substance (fuel, wood, paper clothes etc) and water that releases Carbon dioxide and oxygen with lots of energy.

Carbon dioxide is what we breathe out

37.

Natural gas containing 80% C₂H₆, 15% C₃H₈, 5% C₄H₁₀, is burnt with 50% excess air. Assuming that 90% of the carbon in the hydrocarbons are converted to CO₂ and the rest to CO. Calculate the total atom of Carbon

2.52 mol

2.25 mol

5.22 mol

2.15 mol

38.

Natural gas containing 80% C₂H₆, 15% C₃H₈, 5% C₄H₁₀, is burnt with 50% excess air. Assuming that 90% of the carbon in the hydrocarbons are converted to CO₂ and the rest to CO. Find the total number of atoms of Hydrogen.

6.50 mole

6.40 moles

6.05 mole

5.04 mole

39.

Natural gas containing 80% C₂H₆, 15% C₃H₈, 5% C₄H₁₀, is burnt with 50% excess air. Assuming that 90% of the carbon in the hydrocarbons are converted to CO₂ and the rest to CO. The amount of carbon dioxide produced is:

2.250 moles

2.520 moles

2.025 moles

2.205 moles

40.

2.52 mole

0.252 mole

0.522 mole

0.225 mole

41.

3.520 mole

3.250 mole

3.205 mole

3.502 mole

42.

3.7625 mole

3.2531 mole

3.5213 mole

3.2135 mole

43.

Natural gas containing 80% C₂H₆, 15% C₃H₈, 5% C₄H₁₀, is burnt with 50% excess air. Assuming that 90% of the carbon in the hydrocarbons are converted to CO₂ and the rest to CO. What is the amount of theoretical O₂needed?

3.758 mole

3.578 mole

3.785 mole

3.875 mole

44.

Natural gas containing 80% C₂H₆, 15% C₃H₈, 5% C₄H₁₀, is burnt with 50% excess air. Assuming that 90% of the carbon in the hydrocarbons are converted to CO₂ and the rest to CO. How much O₂ entering the system?

5.8125 mole

5.2581 mole

5.2185 mole

5.5218 mole

45.

21.668 mole

26.816 mole

21.866 mole

28.616 mole

46.

5.20 mole

5.02 mole

2.50 mole

2.05 mole

47.

A material such as coal, gas, or oil that is burned to produce heat or power:

Oxygen gas

kerosene

Flue Gas

Fuel

48.

Which of these is NOT needed for a fire?

Heat

Fuel

Oxygen

Friction

49.

Which poisonous gas is formed as a result of incomplete combustion?

Coal gas

carbon monoxide

carbon dioxide

nitrogen oxide

50.

Which one of the following gases is used in combustion?

Carbon dioxide

Oxygen

Nitrogen

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MIDTERM EXAM

Total questions: 50

Worksheet time: 46mins

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