Answer: The correct option is A.
Explanation: In a chemical reaction, reactants react to form a number of products.
For the formation of products, the bonds of the individual reactants must be broken and the bonds of the products must be formed.
For example: Formation of water from hydrogen gas and oxygen gas. Reaction follows:

The Bonds of hydrogen and oxygen molecule are broken and new bonds between hydrogen and oxygen atoms are formed to give water molecule.
Answer: there is nothing there to answer
Explanation:
The bubbles that were observed after the mixing of the two substances is one of the products of the reaction. It is the carbon dioxide that is produced. To determine the mass of this gas produced, we need to remember the Law of conservation of mass where mass cannot be created or destroyed. With this, we can say that the total mass that goes in a process should be equal to the mass that is goes out of the process no matter what the reaction is. We do as follows:
Mass of reactants = mass of products
11.00 + 44.55 = 51.04 + mass of carbon dioxide
mass of carbon dioxide = 4.51 g
<span>When water decomposes into oxygen and hydrogen, the mass "Remains Constant" as according to Law of Conservation of mass, mass can neither be created not destroyed,.
In short, Your Answer would be Option A
Hope this helps!</span>
Explanation:
According to the analysis, Molarity is amount mole per volume(1L). the amount in mole would be molarity × volume in litres.
0.500M × (250/1000)L= 0.125moles.
I hope this helps**