Question

The equation below shows the action of heat on three metal nitrates.
2S(NO₃)₂ → 2SO + 4NO₂ +O₂
2TNO₃  →  2TNO₂ + O₂
2UNO₃ → 2U +2NO₂ + O₂

1. Arrange the metals S,T and U in the order of reactivity from least to the most reactive. 
2. Give one element that could be used. 

Answer 1

1. U -least reactive
   S
   T-most reactive 
2. silver or mercury