<span>In a titration, the substance that is unknown and being identified is called analyte. A titration is where a known solution or concentration called the titrant is used to identify and measure an unknown substance which is the analyte.</span>
<span>The question does not mention the brand or size of antacid tablets, but some research in the internet shows that for a very common brand, Alka Seltzer, that it takes about 4 tablets to produces 60 mL of gas. So for 120mL it will take 120/60 x 4 or 8 tablets to produce 120 mL of CO2 gas.</span>