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

(51) And they said nothing but: "Our Lord! Forgive us our sins and our transgressions (in keeping our duties to You), establish our feet firmly, and give us victory over the disbelieving folk."

(52) So Allah gave them the reward of this world, and the excellent reward of the Hereafter. And Allah loves Al-Muhsinun (the good-doers - See the footnote of V.3:134 and of V.9:120).

(53) Then after the distress, He sent down security for you. Slumber overtook a party of you, while another party was thinking about themselves (as how to save their ownselves, ignoring the others and the Prophet صلى الله عليه وسلم) and thought wrongly of Allah - the thought of ignorance. They said, "Have we any part in the affair?" Say (O Muhammad صلى الله عليه وسلم): "Indeed the affair belongs wholly to Allah." They hide within themselves what they dare not reveal to you, saying: "If we had anything to do with the affair, none of us would have been killed here." Say: "Even if you had remained in your homes, those for whom death was decreed would certainly have gone forth to the place of their death," but that Allah might test what is in your breasts; and to purify that which was in your hearts (sins), and Allah is All-Knower of what is in (your) breasts.

(54) Those of you who turned back on the day the two hosts met (i.e. the battle of Uhud), it was Shaitan (Satan) who caused them to backslide (run away from the battlefield) because of some (sins) they had earned. But Allah, indeed, has forgiven them. Surely, Allah is Oft-Forgiving, Most Forbearing.

(55) Indeed Allah conferred a great favour on the believers when He sent among them a Messenger (Muhammad صلى الله عليه وسلم) from among themselves, reciting unto them His Verses (the Qur'an), and purifying them (from sins by their following him), and instructing them (in) the Book (the Qur'an) and Al-Hikmah [the wisdom and the Sunnah of the Prophet صلى الله عليه وسلم (i.e. his legal ways, statements, acts of worship)], while before that they had been in manifest error.

(56) (What is the matter with you?) When a single disaster smites you, although you smote (your enemies) with one twice as great, you say: "From where does this come to us?" Say (to them), "It is from yourselves (because of your evil deeds)." And Allah has power over all things.

(57) And let not the disbelievers think that Our postponing of their punishment is good for them. We postpone the punishment only so that they may increase in sinfulness. And for them is a disgracing torment.

(58) "Our Lord! Verily, we have heard the call of one (Muhammad صلى الله عليه وسلم) calling to Faith: 'Believe in your Lord,' and we have believed. Our Lord! Forgive us our sins and expiate from us our evil deeds, and make us die (in the state of righteousness) along with Al-Abrar (the pious believers of Islamic Monotheism).

(59) O mankind! Be dutiful to your Lord, Who created you from a single person (Adam), and from him (Adam) He created his wife [Hawwa (Eve)], and from them both He created many men and women; and fear Allah through Whom you demand (your mutual rights), and (do not cut the relations of) the wombs (kinship) . Surely, Allah is Ever an All-Watcher over you.

(60) And give unto orphans their property and do not exchange (your) bad things for (their) good ones; and devour not their substance (by adding it) to your substance. Surely, this is a great sin.