Write molecularity of the following reaction :
`2NO_((s))+O_(2(g))to2NO_(2(g))`
What is 'calcination' ? How does it differ from 'roasting' ?
Write resonating structures of ozone,
The decomposition of `N_(2)O_(5(g))` at 320 K according to the following equation follows first order reaction :
`N_(2)O_(5(g))to2NO_(2(g))+(1)/(2)O_(2(g))`
The initial concentration of `N_(2)O_(5(g))` is `1*24xx10^(-2)mol.L^(-1)` and after 60 minutes, `0*20xx10^(-2)mol.L^(-1)`. Calculate the rate constant of the reaction at 320 K.

Explanation

Molecularity is the sum of the different reactants which take part in a chemical reaction. Thus, molecularity of the reaction.
`2NO_((g))+O_(2(g))to2NO_(2(g))" is "(2+1)=3`
Calcination : Calcination is a process in which the ore of a metal or other solid material is heated to a high temperature below the melting point of the metal in absence of air or limited supply of air
Example : Decomposition of carbonate minerals as in the calcination of limestone to drive of `CO_(2)`.
`CaCO_(3(s))toCaO_((s))+CO_(2(g))`

The resonating structures of ozone are given below :

`O_(3)` exist as a hybrid of structure I and structure II Each atom may be thought as roughly `sp^(2)` hybrid.
The middle O atom has a lone pair of electrons with a delocalised `pi` orbital over all the three oxygen atoms. The rate constant (K) of first order reaction at temp. t is given by
`k=(2*303)/(t)"log"(C_(O))/(t_(t))`
where, `C_(O)` = initial concentration, `C_(t)` = concentration after time t
For `N_(2)O_(5(g))to2NO_(2(g))+(1)/(2)O_(2(g))`
`C_(O)=1*24xx10^(-2)"mol L"^(-1),C_(t)=0*20xx10^(-2)"mol L"^(-1)t=60` min.
`:." "k=(2*303)/(60)xx"log"(1*24xx10^(-2)"mol L"^(-1))/(0*20xx10^(-2)"mol L"^(-1))`
`=0*038xxlog(6*2)min^(-1)`
`=0*038xx0*792"min"^(-1)=0*030"min"^(-1)`
Thus rate constant of the reaction at 320 K is `0*030" min"^(-1)`.