question_answer 58)

  Which of the following reactions is not correct according to the law of conservation of mass? (a) \[2Mg(s)+{{O}_{2}}(g)\xrightarrow{{}}2MgO(s)\] (b) \[{{C}_{3}}{{H}_{8}}(g)+{{O}_{2}}(g)\xrightarrow{{}}C{{O}_{2}}(g)+{{H}_{2}}O(g)\] (c) \[{{P}_{4}}(s)+5{{O}_{2}}(g)\xrightarrow{{}}{{P}_{4}}{{O}_{10}}(s)\] (d) \[C{{H}_{4}}(g)+2{{O}_{2}}(g)\xrightarrow{{}}C{{O}_{2}}(g)+2{{H}_{2}}O(g)\]

Answer:

  \[{{C}_{3}}{{H}_{g}}(g)+{{O}_{2}}(g)\to C{{O}_{2}}(g)+{{H}_{2}}O(g)\] This equation is not balanced hence it will not obey the law of conservation of mass.