Is the family obligated to pay the accumulated house rent from the period of the First Gulf War, and is it sufficient to distribute the value of the rent to the poor instead of paying it?

The rent for the period must be paid to the landlord or his heirs. It is not permissible to give it as charity to the poor and needy unless it is impossible to deliver the right to them. Ibn Taymiyyah said: "If a person possesses usurped items, borrowed items, deposits, or pledges, and has despaired of knowing their owners, then the correct approach is to give them as charity on their behalf." What is unknown in Islamic law is considered as non-existent, and "Allah does not burden a soul beyond its capacity" (Quran 2:286).