QUESTION 15 Consider the following reaction: 2 N2O5(g) → 4 NO2(g) + O2(g)

if the rate constants at 25 and 45 °C are k25 °C = 3.7 x 10-5 s-1 and k45 °C = 5.1 x 10-4 s-1
Calculate the rate constant at 55 °C

A. 2.8 × 1047 s-1
B. 2.0 × 10-4 s-1
C. 6.1 × 10-1 s-1
D. 1.5 × 10-3 s-1

  the   balanced   equation   for   reaction of   ca metal   with   o2 to   produce   cao   is as below

2 ca+ o2→ 2 cao2

  explanation

the reaction is   balanced     since the   number of atoms   in reactant side is   equal to   number of atoms   in   product side.   for   example   they   are 2   atom of   ca in   reactant   side   and   2   atoms of ca   in   the product side.

  the   process   is a   meet the   requirement   of   redox   reaction because :     calcium   is   oxidized   from   oxidation state 0   to 2+   while   oxygen   is reduced from   oxidation   state   0   to 2-

while cooking a piece of 1/2 pound beef steak, a cast iron pan (2.4kg in weight) was heated 260 celsius.