CBSE Class 12 · 2011 · All India · Chemical KineticsShort Answer

What do you understand by the rate law and rate constant of a reaction? Identify the order of a reaction if the units of its rate constant are:
i) L

^{- 1}

mol s

^{- 1}

ii) L mol

^{- 1}

^{- 1}

Solution

Rate law: the experimentally determined expression giving the rate as the product of reactant concentrations raised to suitable powers, rate

= k [A]^{x} [B]^{y}

.
Rate constant: the rate when each concentration is unity.
(i) L

^{- 1}

mol s

^{- 1}

= mol L

^{- 1}

^{- 1}

⟹

n = 0

— zero order.
(ii) L mol

^{- 1}

^{- 1}

⟹

n = 2

— second order.

CBSE Class 12 Board · 2011 · All India · Subjective