<u>Answer:</u> The moles of water produced are 1.54 moles.
<u>Explanation:</u>
To calculate the number of moles, we use the equation:
Given mass of ethane = 15.42 g
Molar mass of ethane = 30.07 g/mol
Putting values in above equation, we get:
The chemical equation for the combustion of ethane follows:
By Stoichiometry of the reaction:
2 moles of ethane produces 6 moles of water
So, 0.513 moles of ethane will produce = 
of water
Hence, the moles of water produced are 1.54 moles.
Answer: A persistent or non-volatile chemical agent can remain on a surface for more than 24 hours.
Explanation:
Non-volatile substance is defined as the one which does not readily evaporate into its surrounding. Generally, a non-volatile substance has strong intermolecular forces between its molecules.
A non-volatile substance will take more than 24 hours to remain on the surface.
On the other hand, a substance with weak intermolecular forces present in its molecules will readily evaporate into the atmosphere.
For example, acetic acid is a volatile substance and quickly evaporates into the atmosphere.
Thus, we can conclude that a persistent or non-volatile chemical agent can remain on a surface for more than 24 hours.
It changes the boiling point of the water, and it changes the freezing point of the water
The answer is because they are magnetic B.
