In a reduction-oxidation or better known as REDOX reaction, the substance that reduces the oxidation state is known as the substance that is REDUCED. It serves as the oxidizing agent. Thus, Au3+ in this number is considered as the oxidizing agent.
<span>Evaporation and condensation is caused by heat. That is how they are related. Heat causes the liquid to evaporate and float into the atmosphere which causes the formation of clouds.
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The question is incomplete, complete question is :
A chemist must dilute 73.9 mL of 400 mM aqueous sodium carbonate solution until the concentration falls to 125 mM . He'll do this by adding distilled water to the solution until it reaches a certain final volume. Calculate this final volume, in liters. Be sure your answer has the correct number of significant digits.
Answer:
The final volume of the solution will be 0.236 L.
Explanation:
Concentration of sodium carbonate solution before dilution =
Volume of sodium carbonate solution before dilution = 
Concentration of sodium carbonate solution after dilution =
Volume of sodium carbonate solution after dilution = 
Dilution equation is given by:



1 mL = 0.001 L
236 mL = 0.236 L
The final volume of the solution will be 0.236 L.
The observation in the illustration remains in accordance with the law of conservation of mass assuming that moisture is present in the container.
<h3>What is the law of conservation of mass?</h3>
The law state that mass can neither be created nor destroyed. However, mass can be converted from one form to another.
In this case, the ion was placed in a container of pure oxygen. Assuming that moisture is present, iron reacts with oxygen to form rust according to the following equation:

The rust formed will weigh more than the initial weight of the iron.
Without the presence of moisture, one can effectively conclude that the observation violates the law of conservation of mass.
More on the law of conservation of mass can be found here: brainly.com/question/13383562
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