Unrelated and Unalike

Unrelated adjective - Lacking a logical or causal relation.

Unalike and unrelated are semantically related In some cases you can use "Unalike" instead an adjective "Unrelated".

Unalike adjective - Being not of the same kind.

Unrelated and unalike are semantically related in different topic. You can use "Unrelated" instead an adjective "Unalike", if it concerns topics such as unlike, dissimilar.