Answer:
5 moles of carbonic acid will be produced.
Step-by-step explanation:

Moles of sodium bicarbonate = 5 moles
According to reaction , 1 mole of sodium bicarbonate reacts with 1 mole of HCl.
Then 5 moles of sodium bicarbonate will react with:
of HCl
Since, we have 8 moles of HCl. this means that sodium bicarbonate is in limiting amount. Hence, amount of carbonic acid formed will depend upon moles of sodium bicarbonate.
According to reaction , 1 mole of sodium bicarbonate gives with 1 mole of carbonic acid .
Then 5 moles of sodium bicarbonate will give :
of carbonic acid.
5 moles of carbonic acid will be produced.