Answer:
The substance is acidic.
Step-by-step explanation:
When a substance is able to dissolve in water, it means that it is ionic. This just means that the polarity of the water and the polarity of the substance will attract each other to their positive and negative ends respectively. (Positive attracts negative and negative attracts positive).
Litmus paper that is blue and then turns red when introduced to a substance, is known to be acidic.
The opposite can be said when red litmus paper turns blue when introduced to a substance; this means the substance is basic.
Also, if it is sour, then that means it is acidic! Some examples of sour things that are acidic are soft drinks, apples and lemons/limes.