You Do Need power plug adapter while traveling from Mongolia to Syria.

Here is Why You Need An Adapter

The outlet and plug type used in Syria are C, E and L and in Mongolia are C and E. This is how they look like.

Mongolia

In Mongolia, outlets of type C and E are in use.

Type C

Type E

Syria

In Syria, outlets of type C, E and L are in use.

Type C

Type E

Type L