question_answer 1)

  Ions of an element of group I participate in the transmission of nerve signals and transport of sugars and amino acids into cells. This element imparts yellow colour to the flame in flame test and forms an oxide and a peroxide with oxygen. Identify the element and write chemical reaction to show the formation of its peroxide. Why does the element impart colour to the flame?

Answer:

  The element is sodium. This imparts yellow colour to the flame. \[N{{a}^{+}}\] ions participate in the transmission of nerve signals and transport of sugars and amino acids to cells. It forms a monoxide \[(N{{a}_{2}}O)\] and a peroxide\[(N{{a}_{2}}{{O}_{2}})\]. \[Na\xrightarrow{{{O}_{2}}}N{{a}_{2}}O\xrightarrow{{{O}_{2}}}N{{a}_{2}}{{O}_{2}}\] \[4Na+2{{O}_{2}}\to 2N{{a}_{2}}{{O}_{2}}\] The reason for flame colouration is that the energy of the flame causes an excitation of the outermost electrons which on return to their original position give out the energy so absorbed in the visible region. In the case of sodium energy corresponding to yellow light is absorbed and released.