Answer : The mass of oxygen formed must be 3.8 grams.
Explanation :
Law of conservation of mass : It states that mass can neither be created nor be destroyed but it can only be transformed from one form to another form.
This also means that total mass on the reactant side must be equal to the total mass on the product side.
The balanced chemical reaction will be,

According to the law of conservation of mass,
Total mass of reactant side = Total mass of product side
Total mass of
= Total mass of 
As we are given :
The mass of
= 25.3 grams
The mass of
= 23.4 grams
So,



Therefore, the mass of oxygen formed must be 3.8 grams.
The statement that identifies an oxidation-reduction reaction is a reaction in which oxidation numbers change (option C).
<h3>What is a redox reaction?</h3>
A redox or oxidation-reduction reaction is a chemical reaction in which some of the atoms have their oxidation number changed.
In a chemical reaction that involves oxidation and reduction, the oxidation number of the involved ions either decreases or increases.
Therefore, the statement that identifies an oxidation-reduction reaction is a reaction in which oxidation numbers change.
Learn more about redox reaction at: brainly.com/question/13293425
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Answer:
The majority of the molecules move from higher to lower concentration, although there will be some that move from low to high. The overall (or net) movement is thus from high to low concentration.
hope this helps!<3
Answer:
1st Question: A
2nd Question: B
Explanation:
The 1st answer would be A because if a sample is at absolute zero then the sample is at its lowest temperature none of the molecules would be able to move, this is because lower temperature= lower kinetic energy.
The 2nd answer would be B because if a sample has more temperature it speeds up it has more temperature and more kinetic energy, meaning it would move faster because there is more temperature.
it will be shriviled due to the process called osmosis