In a single displacement reaction 9.23g of Al react with exist hydrochloric acid.how many grams of hydrogen will be produce?

I don't think there is an 'exist hydrochloric acid' but rather an 'excess hydrochloric acid'. Write well, please.

Write the balanced equation for the reaction.

2Al + 6HCl \rightarrow 2AlCl_3 + 3H_2

The mole ratio is 2 Al produce 3 H2

Find the amount of moles of Al.
Use proportions to find the amount of moles of H2 produced.
From the amount of moles of H2, find the mass of the gas.

(Relative mass of Al = 27, relative mass of H = 1)