The word(s) "sin" appears 521 time(s) in 480 verse(s) in Quran in Mohsin Khan translation.

(251) See you not that they speak about every subject (praising people - right or wrong) in their poetry?

(252) Ta-sin. [These letters are one of the miracles of the Qur'an, and none but Allah (Alone) knows their meanings]. These are the Verses of the Qur'an, and (it is) a Book (that makes things) clear:

(253) And (remember) Lut (Lot)! When he said to his people. Do you commit Al-Fahishah (evil, great sin, every kind of unlawful sexual intercourse, sodomy) while you see (one another doing evil without any screen)?"

(254) And you will see the mountains and think them solid, but they shall pass away as the passing away of the clouds. The Work of Allah, Who perfected all things, verily He is Well-Acquainted with what you do.

(255) And whoever brings an evil deed (i.e. Shirk - polytheism, disbelief in the Oneness of Allah and every evil sinful deed), they will be cast down (prone) on their faces in the Fire. (And it will be said to them) "Are you being recompensed anything except what you used to do?"

(256) Ta-sin-Mim [These letters are one of the miracles of the Qur'an, and none but Allah (Alone) knows their meanings].

(257) Verily, Fir'aun (Pharaoh) exalted himself in the land and made its people sects, weakening (oppressing) a group (i.e. Children of Israel) among them: killing their sons, and letting their females live. Verily, he was of the Mufsidun (i.e. those who commit great sins and crimes, oppressors, tyrants).

(258) Then the household of Fir'aun (Pharaoh) picked him up, that he might become for them an enemy and a (cause of) grief. Verily, Fir'aun (Pharaoh), Haman and their hosts were sinners.

(259) And when he attained his full strength, and was perfect (in manhood), We bestowed on him Hukm (Prophethood and right judgement of the affairs) and religious knowledge [of the religion of his forefathers i.e. Islamic Monotheism]. And thus do We reward the Muhsinun (i.e. good doers. See the footnote of V.9:120).

(260) He said: "My Lord! For that with which You have favoured me, I will never more be a helper of the Mujrimun (criminals, disbelievers, polytheists, sinners)!"