The reaction \[{{N}_{2}}{{O}_{5}}\,(\text{in}\,CC{{l}_{4}}\,\text{solution})\to 2N{{O}_{2}}(\text{solution})+\frac{1}{2}{{O}_{2}}(g)\] is of first order in \[{{N}_{2}}{{O}_{5}}\] with rate constant \[6.2\times {{10}^{-1}}{{s}^{-1}}.\] What is the value of rate of reaction when \[[{{N}_{2}}{{O}_{5}}]=1.25\,mole\,{{l}^{-1}}\] [AFMC 1998]

• A.                 \[7.75\times {{10}^{-1}}mole\,{{l}^{-1}}{{s}^{-1}}\]         
• B.                 \[6.35\times {{10}^{-3}}mole\,{{l}^{-1}}{{s}^{-1}}\]
• C.                 \[5.15\times {{10}^{-5}}mole\,{{l}^{-1}}{{s}^{-1}}\]          
• D.                 \[3.85\times {{10}^{-1}}mole\,{{l}^{-1}}\,{{s}^{-1}}\]