According to the activity series which of these metals will react with most acids to produce h2 gas

According to activity series of metals, the first metal that will react with most acids is Lithium. Lithium will displace hydrogen from water, steam and acids in order to form hydroxides and hydrogen gas. The other metals in order of their potency are potassium, strontium, calcium, sodium, magnesium, aluminium, zinc, chromium, iron, etc.