Is zakat obligatory on an amount of 200,0 Saudi riyals deposited in the bank and designated for the son's education and the purchase of an apartment in the future, while there is another loan being repaid? And what is the amount of zakat if it is obligatory?

The money in a bank account, if a year has passed and it is subject to Zakat, but if the muzakki (person paying Zakat) has a debt that consumes the money or reduces it below the nisab (minimum threshold), then no Zakat is due on him. This is unless he possesses other non-zakatable assets, such as real estate or a car not needed by him, in which case he should allocate those assets to offset his debt. If these assets cover his debt and a nisab remains, then Zakat becomes obligatory; otherwise, it does not. The nisab for banknotes is approximately equivalent to 85 grams of gold, and the amount due is a quarter of a tenth (2.5%).