which pair of substances would most likely result in the production of a gas when reacting with an…

which pair of substances would most likely result in the production of a gas when reacting with an acid?\nlitmus and methyl orange\nbase and salt\nmetal and carbonate\ncarbon dioxide and water
Answer
Answer:
C. metal and carbonate
Explanation:
Step1: Analyze option A
Litmus and methyl - orange are indicators, not substances that produce gas with acid.
Step2: Analyze option B
A base reacting with an acid forms salt and water, and a salt reacting with an acid usually does not produce gas in a simple reaction.
Step3: Analyze option C
Metals react with acids to produce hydrogen gas (e.g., $Zn + 2HCl=ZnCl_2 + H_2\uparrow$). Carbonates react with acids to produce carbon - dioxide gas (e.g., $CaCO_3+2HCl = CaCl_2 + H_2O+CO_2\uparrow$).
Step4: Analyze option D
Carbon dioxide and water react to form carbonic acid ($CO_2 + H_2O\rightleftharpoons H_2CO_3$), not the other way around when reacting with an acid.