Given the following proposed mechanism, predict the rate law for the rate-determining step.

2 NO2 + Cl2 → 2 NO2Cl (overall reaction)

MechanismNO2 + Cl2 → NO2Cl + Cl (slow)NO2 + Cl → NO2Cl (fast)A) Rate = k[NO2][Cl]B) Rate = k[NO2Cl][Cl]C) Rate = k[NO2]2[Cl2]D) Rate = k[NO2][Cl2]E) Rate = k[NO2Cl]2

D) Rate = K [NO2][Cl2]

Explanation:

2 NO2 + Cl2 → 2 NO2Cl (overall reaction)

NO2 + Cl2 → NO2Cl + Cl (slow)

NO2 + Cl → NO2Cl (fast)

The rate-determining step is the slowest step in a reaction mechanism. Because it is the slowest, it determines the rate of the overall reaction.

Rate of reaction is typically given as;

Rate = K [Reactants]

In the slow step i the reaction mechanism, the reactants are; NO2 and Cl2. Since both are not intermediates, there is no need for further working out.

Rate = K [NO2][Cl2]

output?

explanation:

when 25.0 ml of 0.700 mol/l naoh was mixed in a calorimeter with 25.0 ml of 0.700 mol/l hcl, both initially at 20.0 °c, the temperature increased to 22.1 °c. the heat capacity of the calorimeter is 279 j/°c.

the equation for the reaction is:

naoh + hcl → nacl + h₂o

moles of hcl = 0.0250 l hcl ×

0.700

mol hcl

1 l hcl = 0.0175 mol hcl

volume of solution = (25.0 + 25.0) ml = 50.0 ml

mass of solution = 50.0 ml soln ×

1.00

ml soln

= 50.0 g soln

δt=t2-t1

= (22.1 – 20.0) °c = 2.1 °c

the heats involved are

heat from neutralization + heat to warm solution + heat to warm calorimeter = 0

q1+q2+q3=0

nδh+mcδt+cδt=0

0.0175 mol ×

δh

+ 50.0 g × 4.184 j·g⁻¹°c⁻¹ × 2.1 °c + 279 j°c⁻¹ × 2.1 °c = 0

0.0175 mol ×

δh

+ 439.32 j + 585.9 j = 0

0.0175 mol ×

δh

= -1025.22 j

δh=1025.22j0.0175 mol= -58 600 j/mol = -58.6 kj/mol