gentle, light, little, playful
She gave him a playful slap on the arm as everyone laughed.

hard, painful, sharp, stinging
resounding
friendly, hearty
He gave his brother a hearty slap on the back to congratulate him.

deliver, give sb
Her mother delivered a hard slap and sent her to bed.

get, receive
deserve, need
That boy needs a slap!

slap across
He received a slap across the face.

slap on
They congratulated me with hearty slaps on the back.

with a slap
He hit the water with a resounding slap.

a slap in the face (figurative)
The closure of the school is a slap in the face to the local community.

a slap on the wrist (figurative)
We're hoping that she gets off with a slap on the wrist from the judge.

hard
gently, lightly, playfully
away
She slapped his hand away.

across
The officer slapped him hard across the face.

on
She slapped the boy on the leg.

slap sb in the face (usually figurative)
I felt like I had been slapped in the face.

Slap is used with these nouns as the object:
bottom, forehead, hand, knee, order, palm, tariff