Based on Arrhenius theory, explain why CaCI2(aq) can be considered a neutral solution rather than an acidic solution or a basic solution?

Another question is in an experiment ammonia has, NH3(aq) reacted with the water to form the aqueous ammonia ions, NH4+(aq). When red litmus paper was placed in contact with the aqueous solution the paper turned blue. This indicated a basic solution.

a. Identify the acid and the base in the reaction between dissolved ammonia gas, Nh3(aq) and water. Explain your answer

B. Identify the conjugate acid and the conjugate base of the reaction. Explain your answer

C. Write the complete chemical equation for the reaction between NH3(aq) and H2O(I)

Another question is: The oxides is carbon, sultry and nitrogen can be harmful when released into the atmosphere. Why are these oxides so harmful. Give one reason that applies to all these oxides?