12 × 10–5 mol L–1s–1
At t = 250 s
rinst = 1 22 × 10–4
 mol L–1s–1
     t = 350 s
rinst = 1 0 × 10–4 mol L–1s–1
     t = 450 s
rinst = 6 4 ×× 10–5 mol L–1s–1
Now consider a reaction
Hg(l) + Cl2 (g) ® HgCl2(s)
Where stoichiometric coefficients of the reactants and products are
same, then rate of the reaction is given as
[
]
[
]
[
]
2
2
Hg
Cl
HgCl
Rate of reaction = –
–
t
t
t
∆
∆
∆
=
=
∆
∆
∆
i