Final answer:
The reaction between calcium (Ca) and hydrochloric acid (HCl) to form calcium chloride (CaCl2) and hydrogen gas (H2) is a single displacement reaction. It exemplifies a metal element reacting with an acidic compound to displace hydrogen and form a salt and hydrogen gas.
Step-by-step explanation:
When calcium (Ca) reacts with hydrochloric acid (HCl), a single displacement reaction occurs where calcium replaces hydrogen in hydrochloric acid to form calcium chloride (CaCl2) and hydrogen gas (H2). This type of chemical reaction where an element reacts with a compound and displaces another element from it is known as a single displacement reaction or substitution reaction. In this case, the balanced reaction would be Ca + 2HCl → CaCl2 + H2.
Related Information:
The reaction of calcium carbonate (CaCO3) with hydrochloric acid to produce calcium chloride, carbon dioxide (CO2), and water (H2O) is an example of a double displacement reaction, also known as a metathesis reaction. Here, two compounds exchange ions to form two new compounds. This reaction is represented by 2 HCl(aq) + CaCO3(aq) → CaCl2(aq) + CO2(g) + H2O(l).