Which of the following methods is the best test to detect the presence of water in a liquid?

Given below are two statements:
Statement-$I$: Permutit process is more efficient compared to the synthetic resin method for the softening of water.
Statement-$II$: Synthetic resin method results in the formation of soluble sodium salts.
In the light of the above statements,choose the most appropriate answer from the options given below:

How and why does the density of liquid water change on prolonged electrolysis?

Deionized water is obtained by passing hard water through

Which of the following is not a water absorber and dehydrating substance?

What is used to soften water by the Clark's method?