Balancing Chemical Reactions Practice

This unbalanced equation represents a chemical reaction:

Pb(NO₃)₂ + NaI → NaNO₃ + PbI₂

What is the coefficient for NaI once the equation is balanced?

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Which represents a balanced chemical equation?

• CO₂ + 2H₂O → 2CH₄ + 2O₂

• CH₄ + O₂ → CO₂ + H₂O

• CH₄ + 2O₂ → CO₂ + 2H₂O

• CO₂ + H₂O → CH₄ + O₂

Which set of coefficients correctly balances the equation?

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• 1, 3, 1, 1

• 2, 3, 1, 1

• 2, 3, 1, 3

In the late 1700s, Antoine Lavoisier performed a series of experiments to find out what happened when a substance burned. In each experiment, he observed that the weight of a container and its contents was the same at the end of the experiment as it had been in the beginning. These observations led him to propose the law of

• combustion.

• fixed proportions.

• conservation of mass.

• conservation of energy

The chemical equation shows the amount of the reactants used and the amount of only one of the products formed. How much water should be formed in this chemical reaction?

• 5 g

• 9 g

• 27 g

• 31 g

The conservation of matter can be demonstrated by using chemical equations. Which chemical equation demonstrates the conservation of matter?

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Plants use the process of photosynthesis to convert carbon dioxide and water into glucose and oxygen. If a plant uses 44 grams of carbon dioxide and 18 grams of water to produce 32 grams of oxygen, how many grams of glucose are produced for the plant to use?

• 26 grams

• 30 grams

• 62 grams

• 94 grams

The diagram represents the chemical reaction that occurs when propane combusts. In the reaction, for every molecule of propane, how many molecules of oxygen are used?

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• 3

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The unbalanced equation below shows the combustion of methane. Which series of numbers represents the coefficients necessary to balance the equation?

• 2, 2, 1, 4

• 1, 1, 1, 2

• 1, 2, 1, 2

• 0, 3, 2, 2

Nitric acid can oxidize iron(II) ions to iron(III) ions by the following reaction. _HNO₃ + _Fe⁺² + _H⁺ ------- _NO + _Fe⁺³ + _H₂O

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