Is it permissible to give charity with the intention that it be on behalf of deceased Muslims who have no one to give charity on their behalf?

Your giving of charity on behalf of deceased Muslims and dedicating its reward to them is permissible and reaches them, and you will receive the reward. We have clarified in a previous fatwa that the preponderant view is that the reward of acts of devotion reaches deceased Muslims, and this is the madhhab of Imam Abu Hanifa and Ahmad ibn Hanbal. Al-Kasani said: "Whoever fasts, prays, or gives charity and dedicates its reward to others, whether living or dead, it is permissible, and its reward reaches them according to Ahl al-Sunnah wal Jama'ah." Ahmad said: "Everything reaches the deceased, whether it is charity or anything else." It was also narrated from him that he said: "When you enter the graveyards, recite Ayat al-Kursiyy and {Qul Huwa Allahu Ahad} three times, then say: 'O Allah, indeed its grace is for the people of the graves,' meaning its reward."