Question

how to identify this is a base or acid

Answer 1

Hey friend your answer is here
To determine whether a substance is an acid or a base, count the hydrogens on each substance before and after the reaction. If the number of hydrogens has decreased that substance is the acid (donates hydrogen ions). If the number of hydrogens has increased that substance is the base (accepts hydrogen ions).
Hope it's helpful to you

Answer 2

if the blue litmus turns in red litmus then it is acid
if red litmus turns into blue litmus then it is base