For the combustion reaction 4NH3(g)+5O2(g)→4NO(g)+6H2O(g), how many liters of O2(g) would react with 500 L of NH3 at STP?
Answers
(i) 3NO(g) → N2O(g)
Rate = k[NO]2
Here rate law is dependent on concentration of NO only.And power raised to concentration of NO is 2. Hence order of reaction is 2.
To find dimensions of rate constant (K)- We know rate of chemical reaction is measured in . So, unit of K will be
i.e. [concentration]-1[ time]-1 . If concentration is in mol L-1 and time is in sec. then dimensions of k will be : mol-1 L sec-1
(ii) H2O2(aq) + 3I-(aq) + 2H+ → 2 H2O(l) + I3-
Rate = k[H2O2][I-]
Here rate law is dependent on concentration of H2O2 and I-. And power raised to concentration of H2O2 is 1, and power raised to concentration of I- is 1. order is sum of powers hence, order of given reaction is 2.
To find dimensions of rate constant (K)- We know rate of chemical reaction is measured in [concentration/time]. So, unit of K will be [Concentration]/[time][concentration]2 i.e. [concentration]-1[ time]-1. If concentration is in mol L-1 and time is in sec then dimensions of k will be mol-1 L sec-1
(iii) CH3CHO(g) → CH4(g) + CO(g)
Rate = k[CH3CHO]3/2
Here rate law is dependent on concentration of CH3CHO.And power raised to CH3CHO is 3/2. Hence order of reaction is 3/2.
To find dimensions of rate constant (K)- We know rate of chemical reaction is measured in [concentration/time]. So, unit of K will be [Concentration]/[time][concentration]3/2 i.e. [concentration]-1/2[time]-1.
If concentration is in mol L-1 and time is in sec. Then dimensions of K will be mol-1/2L1/2 sec-1
(iv) C2H5Cl (g) → C2H4(g) + HCl(g)
Rate = k[C2H5Cl]
Here rate law is dependent on concentration of C2H5Cl. And power raised to C2H5Cl is 1. Hence order of reaction is 1.
To find dimensions of rate constant (K)- We know rate of chemical reaction is measured in [concentration/time]. So, unit of K will be [Concentration]/[time][concentration]1. i.e. [time]-1
If concentration is in mol L-1 and time is in sec. Then dimensions of K will be sec-1.