Question

In: Chemistry

In The first order reaction A -> products, [A] = .400 M initally and .250 M...

In The first order reaction A -> products, [A] = .400 M initally and .250 M after 15 min, what will [A] be after 175 min?

Solutions

Expert Solution

Calculation of rate constant :

For a first order reaction rate constant , k = ( 2.303 /t )x log ( Mo / M)

Where

Mo = initial concentration = 0.400 M

M = concentration after time t = 0.250 M

t = time = 15 min

k = rate constant = ?

Plug the values we get k = ( 2.303 /15 )x log (0.400 / 0.250)

                                     = 0.0313 min-1

Now calculation of concentration of A after 175 min :

For a first order reaction rate constant , k = ( 2.303 /t )x log ( Mo / M)

Where

Mo = initial concentration = 0.400 M

M = concentration after time t = ?

t = time = 175 min

k = rate constant = 0.0313 min-1

Plug the values we get log ( Mo / M) = (kt) / 2.303

                                                      = ( 0.0313 x175) / 2.303

                                                      = 2.38

                                          Mo / M = 102.38

                                                     = 240.65

                                                 M = Mo / 240.65

                                                     = 0.400 / 240.65

                                                     = 1.66x10-3 M

Therefore the concentration of [A] after 175 min is 1.66x10-3 M


Related Solutions

A. If the rate law for the reaction 2A + 3B products is first order in...
A. If the rate law for the reaction 2A + 3B products is first order in A and second order in B, then what is the rate law? B. A reaction was found to be third order in A. If the concentration of A is increased by a factor of 3, Then how much the reaction rate will be affected? C. The overall order of a reaction is 2. What will be the unit of the rate constant? Show calculation....
A reaction in which A, B, and C react to form products is first order in...
A reaction in which A, B, and C react to form products is first order in A, second order in B, and zero order in C. Write a rate law for the reaction. Write a rate law for the reaction. Rate=k[A][B] Rate=k[A][B]2 Rate=k[A][B][C] Rate=k[A]2[B]3[C] Part B Part complete What is the overall order of the reaction? Part C By what factor does the reaction rate change if [A] is doubled (and the other reactant concentrations are held constant)? Rate2Rate1 =...
The isothermal reaction of A to B is a first order reaction in A. A 5,000...
The isothermal reaction of A to B is a first order reaction in A. A 5,000 liter plug flow reactor is fed with A at concentration of 4 gmol/liter and volumetric flow of 800 L/min. At these conditions the conversion of A is 95%. We have two CSTRs that are 2000 and 7000 liters and can be place in series to replace the PFR. a. Can the two CSTR’s in series provide 95% conversion in replacement of the PFR? Select...
1)A reaction(A-products) is found to be first order with a rate constant of 2.97*10^-3 / min....
1)A reaction(A-products) is found to be first order with a rate constant of 2.97*10^-3 / min. What is the half life for this reaction? 2) If the reaction described in probrem 1 starts with an initial concentration of 1.00M of reactant A, What is the concentration of A after 300min? 3) What is the reaction oreder and what is the value of the rate constant? IN(H2O2) y=0.00835x-0.00493 1/H2O2 y=0.00460x-0.847 H2O2 y=-0.000264x+0.841
For a reaction that is either zero, first, or second order, which reaction order would leave...
For a reaction that is either zero, first, or second order, which reaction order would leave the most reactant remaining after the reaction has occurred for an hour? Assume k does not change.
(a) The reaction A(aq) → B(aq) is a first order reaction with respect to A(aq). The...
(a) The reaction A(aq) → B(aq) is a first order reaction with respect to A(aq). The concentration of A(aq) after 200.0 seconds of reaction is 0.960 M and the concentration of A(aq) after 1000.0 seconds of reaction is 0.738 M. What was the concentration of A(aq) after 661.0 seconds of reaction? (b) The reaction A(aq) → B(aq) + C(aq) is a first order reaction with respect to A(aq). The half-life of A(aq) is 74.5 s at 25.0oC. Its activation energy...
What is the reaction order with respect to initiator concentration (e.g. first order, second order, etc.)...
What is the reaction order with respect to initiator concentration (e.g. first order, second order, etc.) for each of the following steps: a. Initiation b. Propagation c. What is the relationship between initiator concentration and critical chain length?
a. A certain first-order reaction (A→products) has a rate constant of 3.00×10−3 s−1 at 45 ∘C....
a. A certain first-order reaction (A→products) has a rate constant of 3.00×10−3 s−1 at 45 ∘C. How many minutes does it take for the concentration of the reactant, [A], to drop to 6.25% of the original concentration? b. A certain second-order reaction (B→products) has a rate constant of 1.85×10−3M−1⋅s−1 at 27 ∘C and an initial half-life of 300 s . What is the concentration of the reactant B after one half-life?
The activation energy of the first-order decomposition of N2O into N2 and O is Ea= 250...
The activation energy of the first-order decomposition of N2O into N2 and O is Ea= 250 kJ/mol. If the half-life of the reactant is t1/2= 7.5*10^6 s at 673K, what will it be at 773K?
The reaction A(aq) ---> B(aq) + C(aq) is a first order reaction. The half-life of A(aq)...
The reaction A(aq) ---> B(aq) + C(aq) is a first order reaction. The half-life of A(aq) is 86.6 s at 25.0oC and its half-life is 66.2 s at 45.0oC. What is its half-life (in s) at 65.0oC?
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT