Question

a candle slowly burns until the last bit of wax and wick are gone. the two reactants in this chemical reaction are the wick and oxygen. which statement correctly identifies components as part of the system or the surroundings for this chemical reaction? (1 point)

• all of the air is part of the system.

• all of the candle is part of the surroundings.

• in the air, only the oxygen is part of the system.

• in the candle, only the wick is part of the surroundings.

Explanation:

In chemical reaction system definitions, the system includes only the reactants and products directly involved in the reaction. The candle (wax + wick) and the oxygen that reacts with it are the system; the rest of the air (nitrogen, argon, etc.) and non-reacting materials are surroundings.

• "All of the air is part of the system" is wrong because most air components don't react.
• "All of the candle is part of the surroundings" is wrong because the candle is a reactant (part of the system).
• "In the air, only the oxygen is part of the system" is correct because only oxygen from air participates in the combustion reaction.
• "In the candle, only the wick is part of the surroundings" is wrong because both wax and wick are reactants in the system.

Answer:

C. In the air, only the oxygen is part of the system.