Journal entry for payment of unrecorded liabilities in cash is given as-

Cash/Bank A/c             Dr.

     To Realisation A/c

The same entry is given for the recording of the sale of unrecorded assets. Why is it so?

For payment of any Unrecorded Liability:

Realisation A/c ...Dr.

 . . To Cash/Bank A/c

.

.

For realisation of any Unrecorded Asset:

Cash/Bank A/c ...Dr.

 . . To Realisation A/c

.

.

.

[Please note that the entry given by you is for realisation of unrecorded assets, not for payment of unrecorded liabilities. For each of these purposes, we pass different journal entries.]