Should the Zakah (obligatory charity) giver tell the poor recipient that this is the Zakah of his money?
No, he shouldn`t. But, the Zakah giver should make an intention in his heart that it is the Zakah of his money when paying it to the poor. And Allah Knows Best.
What is the ruling on making up missed fasts from many years?
A Muslim must make up for any missed fasts, as they are a debt owed to Allah. The Prophet ﷺ said:
"The debt owed to Allah is more deserving of being fulfilled." [Narrated by Muslim]
Whoever has missed fasts must make them up as long as they are alive and capable of fasting.
Is it permissible for the wife to give the Zakah (obligatory charity) of her money to her poor husband?
Yes, it is permissible for the wife to give from the Zakah of her money to her poor husband. And Allah Knows Best.
I`m keeping a plot of land (10 Dunums) for my children. Is it liable for Zakah?
Praise be to Allah, The Lord of the Worlds.
Land that is purchased with the intention of ownership and personal benefit—meaning to retain it for use and not for trade—is not subject to zakāh, as such property is not considered from trade commodities (ʿurūḍ al-tijārah).
It is stated in Al-Ḥāwī al-Kabīr:
“If it is property and one intends it for trade, then zakāh is due upon it; but if he intends it for personal possession, then no zakāh is due upon it.” And Allah, the Exalted, knows best.