how to determine whether an unknown solution is acids or bases?

hi
1.To check whether the given substance is a acid or a base.
Use litmus paper.if you dip red litmus paper into NaOH solution
it turns blue while viceversa is not possible.Similarly if you dip blue litmus paper into HCl solution it turns red while in NaOH it does not.

2.For take a known volume of NaOH in a flask,and the unknown HCl in a burette(Its something in which you can fill up HCl to a known volume,note the initial volume.
now open the tap in the burette and make it react with known NaOH.You can find when it has reacted completely by using an indicator which indicates when the reaction has completed by changing its color.Now note the volume of HCl subtract it with the initial volume to get the volume of HCl reacted let it be x.
Known volume of NaOH be y.

Then use the equation M*x=m*y

here M is the unknown concentration of HCl ,x is the volume of HCl you calculated.m is 0.2M of NaOH and y is the known volume of NaOH

now you can get the concentration of HCl.

3.HCl is a strong acid,because it can easily dissociate to give H+  and Cl-

hope this helps


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