Dinitrogen pentoxide decomposes in the gas phase to form nitrogen dioxide and oxygen gas. The reaction is first order in dinitrogen pentoxide and has a half-life of 2.81 hat 25$^{\circ} \mathrm{C}$. If a 1.5-L reaction vessel initially contains 745 torr of $N_2O_5$ at 25$^{\circ} \mathrm{C}$, what partial pressure of $O_2$ is present in the vessel after 215 minutes?

For the decomposition of gaseous dinitrogen pentaoxide, $2 \mathrm { N } 2 \mathrm { O } 5 ( \mathrm { g } ) \rightarrow 4 \mathrm { NO } 2 ( \mathrm { g } ) + \mathrm { O } 2 ( \mathrm { g } )$ the rate constant is $\mathrm { k } = 2.8 \times 10 ? 3 \mathrm { s } ? 1 \ \mathrm { at } \ 60 ^ { \circ } \mathrm { C. }$ The initial concentration of N2O5 is 1.58 mol/L.

What is [N2O5] after 5.00 min?

This reaction was monitored as a function of time: $\mathrm{AB} \longrightarrow \mathrm{A}+\mathrm{B}$ A plot of 1/ [A B] versus time yields a straight line with a slope of +0.55 $\mathrm{M} \cdot \mathrm{s}$. a. What is the value of the rate constant (k) fo r this reaction at this temperature? b. Write the rate law for the reaction. c. What is the half-life when the initial concentration is 0.55 M? d. If the initial concentration of AB is 0.250 M, and the reaction mixture initially contains no products, what are the concentrations of A and B after 75 s?

Write balanced equations for each reaction. Dinitrogen tetroxide gas decomposes into nitrogen dioxide gas.

At 400 K oxalic acid decomposes according to the reaction: $\mathrm{H}_{2} \mathrm{C}_{2} \mathrm{O}_{4}(g) \longrightarrow \mathrm{CO}_{2}(g)+\mathrm{HCOOH}(g)$ In three separate experiments, the initial pressure of oxalic acid and final total pressure after 20,000 s are measured.

$$\begin{matrix} \text{Experiment} & \text{1} & \text{2} & \text{3}\\ \ {P_{\mathrm{H}_{2} \mathrm{C}_{2} \mathrm{O}_{4}} \text { at } t=0} & \text{65.8} & \text{92.1} & \text{111}\\ \ {P_{\text {Total }} \text { at } t=20,000 \mathrm{s}} & \text{94.6} & \text{132} & \text{160}\\ \end{matrix}$$

Find the rate law of the reaction and its rate constant.

At $45^{\circ} \mathrm{C}$ dinitrogen pentoxide $\left(\mathrm{N}_{2} \mathrm{O}_{5}\right)$ decomposes into nitrous dioxide $\left(\mathrm{NO}_{2}\right)$ and oxygen $\left(\mathrm{O}_{2}\right)$ according to the law of uninhibited decay. An initial amount of 0.25 M of dinitrogen pentoxide decomposes to 0.15 M in 17 minutes. How much dinitrogen pentoxide will remain after 30 minutes? How long will it take until 0.01 M of dinitrogen pentoxide remains?

Express each fraction as a percent. $\frac{3}{40}$

The first-order rate constant for the decomposition of $\ce{N2O5}$:

$$\ce{2N2O5(g) -> 4NO2(g) + O2(g)}$$

at 70 $\degree$C is 6.82 $\times$ 10$^{-3}$ s$^{-1}$.

Suppose we start with 2.60 $\times$ 10$^{-2}$ mol of $\ce{N2O5(g)}$ in a volume of 2.3 L.

(a) How many moles of $\ce{N2O5}$ will remain after 7.0 min?

(b) How many minutes will it take for the quantity of $\ce{N2O5}$ to drop to 1.$\times$ 10$^{−2}$ mol?

Suppose that the function T has period 7 and that T(0) = 3.

Evaluate T(7).

The hydrolysis of sucrose ($C _{12}H_{22}O_{11}$) into glucose and fructose in acidic water has a rate constant of $1.8 \times 10^{-4} \mathrm{s}^{-1} \text { at } 25^{\circ} \mathrm{C}$. Assuming the reaction is first order in sucrose, determine the mass of sucrose that is hydrolyzed when 2.55 L of a 0.150 M sucrose solution is allowed to react for 195 minutes.

At 700 K acetaldehyde decomposes in the gas phase to methane and carbon monoxide. The reaction is: $\mathrm{CH}_{3} \mathrm{CHO}(g) \longrightarrow \mathrm{CH}_{4}(g)+\mathrm{CO}(g)$ A sample of $CH_3CHO$ is heated to 700 K and the pressure is measured as 0.22 atm before any reaction takes place. The kinetics of the reaction are followed by measurements of total pressure and these data are obtained:

$$\begin{matrix} \text{t (s)} & \text{0} & \text{1000} & \text{3000} & \text{7000}\\ \ {P_{rotal} (atm)} & \text{0.22} & \text{0.24} & \text{0.27} & \text{0.31}\\ \end{matrix}$$

Find the rate law, the rate constant, and the total pressure after $2.00 \times 10^{4}$ s.

The tabulated data were collected for this react ion at 500$^{\circ} \mathrm{C}$: $\mathrm{CH}_{3} \mathrm{CN}(g) \longrightarrow \mathrm{CH}_{3} \mathrm{NC}(g)$

$$\begin{matrix} \text{Time (h)} & \ {[CH_3CN] (M)}\\ \text{0.0} & \text{1.000}\\ \text{5.0} & \text{0.794}\\ \text{10.0} & \text{0.631}\\ \text{15.0} & \text{0.501}\\ \text{20.0} & \text{0.398}\\ \text{25.0} & \text{0.316}\\ \end{matrix}$$

a. Determine the order of the reaction and the value of the rate constantat this temperature. b. What is the half-life for this reaction (at the initial concentration)? c. How long will it take for 90% of the $CH_3CN$ to convert to $CH_3C$?

Nitrogen dioxide,

$$NO_2$$

, can be converted to dinitrogen pentoxide,

$$N_2O_5$$

, by reacting it with ozone,

$$O_3$$

. The reaction of

$$NO_2$$

takes place according to the following equation:

$$2 \mathrm { NO } _ { 2 } ( g ) + \mathrm { O } _ { 3 } ( g ) \longrightarrow \mathrm { N } _ { 2 } \mathrm { O } _ { 5 } ( s \text { or } g ) + \mathrm { O } _ { 2 } ( g )$$

a. Calculate the percentage yield for a reaction in which 0.38 g of

$$NO_2$$

reacts and 0.36 g of

$$N_2O_5$$

is recovered. b. What mass of

$$N_2O_5$$

will result from the reaction of 6.0 mol of

$$NO_2$$

if there is a 61.1% yield in the reaction?

If a temperature increase from 10.0 °C to 20.0 °C, the rate constant doubles. What is the value of the activation barrier for the reaction?