Question

identify the reactant(s) in the reaction: hypochlorous acid + hydrochloric acid ------ --> chlorine gas + water
option 1: chlorine gas and water
option 2: hydrochloric acid and chlorine gas
option 3: hypochlorous acid, hydrochloric acid, chlorine gas, and water
option 4: hypochlorous acid and hydrochloric acid

what is the result of the reaction between nitrogen dioxide and water?
option 1: nitric acid
option 2: hydronitric acid
option 3: an aqueous solution of nitrogen dioxide
option 4: a solution of hydrogenated nitrogen dioxide and hydrogen gas

Explanation:

First Question:

In a chemical reaction, reactants are the substances that undergo the reaction (on the left side of the arrow). Here, hypochlorous acid and hydrochloric acid are on the left, so they are reactants. Products (chlorine gas, water) are on the right. Other options include products or incorrect combinations.

Second Question:

The reaction of nitrogen dioxide ($\ce{NO_2}$) with water ($\ce{H_2O}$) is $\ce{3NO_2 + H_2O = 2HNO_3 + NO}$. So the main acidic product is nitric acid ($\ce{HNO_3}$). Hydronitric acid is not formed here, $\ce{NO_2}$ doesn't just dissolve to form an aqueous solution without reaction, and hydrogen gas isn't a product of this reaction.

Answer:

D. hypochlorous acid and hydrochloric acid