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CHE 105/110 Introduction to Chemistry - Exercises and Answers

Composition, Decomposition, and Combustion Reactions

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QUESTION ANSWER

1.

Which is a composition reaction and which is not?

  1. NaCl + AgNO3 → AgCl + NaNO3
  2. CaO + CO2 → CaCO3

1.

  1. not composition
  2. composition

3.

Which is a composition reaction and which is not?

  1. 2SO2 + O2 → 2SO3
  2. 6C + 3H2 → C6H6

3.

  1. composition
  2. composition

5.

Which is a decomposition reaction and which is not?

  1. HCl + NaOH → NaCl + H2O
  2. CaCO3 → CaO + CO2

5.

  1. not decomposition
  2. decomposition

7.

Which is a decomposition reaction and which is not?

  1. Na2O + CO2 → Na2CO3
  2. H2SO3 → H2O + SO2

7.

  1. not decomposition
  2. decomposition

9.

Which is a combustion reaction and which is not?

  1. C6H12O6 + 6O2 → 6CO2 + 6H2O
  2. 2Fe2S3 + 9O2 → 2Fe2O3 + 6SO2

9.

  1. combustion
  2. combustion

11.

Which is a combustion reaction and which is not?

  1. P4 + 5O2 → 2P2O5
  2. 2Al2S3 + 9O2 → 2Al2O3 + 6SO2

11.

  1. combustion
  2. combustion

13.

Is it possible for a composition reaction to also be a combustion reaction? Give an example to support your case.

13.

Yes; 2H2 + O2 → 2H2O (answers will vary)

15.

Complete and balance each combustion equation.

  1. C4H9OH + O2 → ?
  2. CH3NO2 + O2 → ?

15.

  1. C4H9OH + 6O2 → 4CO2 + 5H2O
  2. 4CH3NO2 + 3O2 → 4CO2 + 6H2O + 2N2

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