What does the IPA stand for? 
International Phonetic Alphabet.
What is the smallest meaningful unit in a language?
Morpheme
What does semantics study?
The meaning of words, phrases, and sentences.
What is the smallest unit of sound that can change the meaning of a word?
Phoneme
How many morphemes are there in the word unhappiness?
Three morphemes.
Which semantic relationship exists between dog and puppy
Hyponymy
(puppy is a type of dog).
Is the English sound /p/ voiced or voiceless? :max_bytes(150000):strip_icc()/voiced-and-voiceless-consonants-1212092-final-ef2ba49d76cb4d508e740833be4da7a7.png)
Voiceless
Which morpheme changes the meaning or creates a new word: derivational or inflectional?

Derivational morpheme.
What is a synonym?
A word that has the same or nearly the same meaning as another word.