The spelling of the word "Piapec" can be explained using IPA phonetic transcription. The first sound is /pi/, which is pronounced as the letter "p" followed by the vowel sound /i/. The next sound is /ə/, which is pronounced as a short schwa sound. Finally, the word ends with /pɛk/, which is pronounced as the letters "p" and "e" followed by the consonant sound /k/. Therefore, the correct spelling of the word is "Piapec".