18. Ca(s)+ 2HNO2 (aq) + Ca(NO2)2 (aq) + H2 (9)
What type of chemical reactions is the chemical reaction described
above?

Displacement reaction

Explanation:

In displacement reactions, an element replaces another element in a compound.

Ca(s)+ 2HNO2 (aq) + Ca(NO2)2 (aq) + H2 (g).

In the reaction above, calcium (Ca) displaces hydrogen (H) from its compound (nitrous acid, HNO2) due to its higher position in the reactivity series than hydrogen. Hence, displaced hydrogen is liberated as gas at the end of the displacement reaction while calcium forms its trioxonitrate salt.

Thus, it is a displacement reaction.

adding or remove a gaseous reactant or product changes the concentrations. if the concentration of reactant or product is increased, the system will shift away from the side in which concentration was increased (i.e. if the concentration of reactants is increased, the system will shift toward the products. if more products are added, the system will shift to form more reactants). conversely, if the concentration of reactant or product is decreased, the system will shift toward the side in which concentration was decreased (i.e. if reactants are removed, the system will shift to form more reactants. if the concentration of products is decreased, the equilibrium will shift toward the products).

explanation: