question_answer 95)

  An element A burns with golden flame in air. It reacts with another element B, atomic number 17 to give a product C. An aqueous solution of product C on electrolysis gives a compound D and liberates hydrogen. Identify A, B, C and D. Also write down the equations for the reactions involved. 

Answer:

                  A is sodium (Na) because it burns with golden flame in air. B is chlorine () as its atomic number is 17. When Na reacts with,is formed. Hence, C is sodium chloride (). Aqueous   solution   of,   on   electrolysis   gives   sodium   hydroxide. Thus, D is sodium hydroxide            ().