The firstorder rate constant for photodissociation of A is 5.97 1/h. Calculate the time needed for the concentration of A to decrease to the following quantities. a. 5% of its original value h b. onethird of its initial concentration h
157,047 results

chemistry
The firstorder rate constant for photodissociation of A is 5.97 1/h. Calculate the time needed for the concentration of A to decrease to the following quantities. a. 5% of its original value h b. onethird of its initial concentration h 
Chemistry Lab
*The decomposition of acetaldehyde is a first order reaction with a specific rate constant of 6.0 X 10^1 / min. CH₃CHO > CH₄ + CO 1. Calculate the initial rate when the concentration of acetaldehyde is 0.80M. 2. Calculate the time needed for the concentration of the ... 
Chemistry
The halflife for the secondorder reaction of a substance A is 55.8 s when concentration of initial A = 0.69 M. Calculate the time needed for the concentration of A to decrease to the following values. (a) 1/8 of its original value (b) 1/9 of its original value 
Chemistry
The halflife for the secondorder reaction of a substance A is 58.2 s when A0 = 0.63 mol L1 Calculate the time needed for the concentration of A to decrease to the following values. (a) onethird of its original value (b) onesixth of its original value (c) oneseventh of ... 
Chemistry
I know how to find halflives, but I have trouble finding the length of time it would take for the concrentration of X to decrease to Y% of its initial value. For example, this is one of the problems: Methyl isocyanide, CH3NC, isomerizes when heated to give acetonitrile (... 
chemistry
A 50mL Mohr buret is connected to a 1ft length of capillary tubing. The buret is then filled with water and the volume of water versus time is monitored as the water gradually flows through the capillary tubing. This process is found to be firstorder with a rate constant of... 
chemistry
The reaction Cl(g)+ O3(g) > ClO(g)+ O2(g) is the firstorder in both reactants. Determine the pseudofirstorder and secondorder rate constants for the reaction from the data in the table below if the initial ozone concentration was ..0000000000825 M or 8.25*10^11 M. ... 
chemistry
The reaction Cl(g)+ O3(g) > ClO(g)+ O2(g) is the firstorder in both reactants. Determine the pseudofirstorder and secondorder rate constants for the reaction from the data in the table below if the initial ozone concentration was ..0000000000825 M or 8.25*10^11 M. ... 
Chemistry
A 50mL Mohr buret is connected to a 1ft length of capillary tubing. The buret is then filled with water and the volume of water versus time is monitored as the water gradually flows through the capillary tubing. This process is found to be firstorder with a rate constant of... 
Chemistry
A 50mL Mohr buret is connected to a 1ft length of capillary tubing. The buret is then filled with water and the volume of water versus time is monitored as the water gradually flows through the capillary tubing. This process is found to be firstorder with a rate constant of... 
Chemistry
What would be the concentration of dinitrogen pentoxide after 6.00 X 10(2) seconds and how long would it take for the concentration of N2O2 to decrease to 10.0% of its initial value in the following equation... N2O5 to NO2 and O2 initial concentration is 1.65 X 102mol/L rate ... 
Science work
A reaction is thought to be second order with respect to the concentration of carbon monoxide. What evidence would support this? Answer options... A. Changing the initial concentration would have no effect on the rate. B. Any change in the initial concentration would cause a ... 
chemistry
Butadiene, C4H6, in the gas phase undergoes a reaction to produce C8H12. The following data were obtained for the reaction. [C4H6] Time (min) 1 0 0.98 20 0.91 100 0.66 500 0.49 1000 0.32 2000 0.25 3000 Determine the order of the reaction. Order with respect to [C4H6] = 2 ... 
chemistry
he decomposition of nitrogen dioxide at a high temperature is second order in this reactant. NO2(g) NO(g) + 1/2 O2(g) The rate constant for this reaction is 3.40 L/mol·min. Determine the time needed for the concentration of NO2 to decrease from 2.30 mol/L to 1.30 mol/L. 
Ap Chemistry
I have no idea where to start with this problem: A certain reaction has the following general form: aA > bB At a particular temperature and (A)o = 2.00(10^2)M, concentration versus time data were collected for this reaction, and a plot of In(A) versus time resulted in a ... 
AP Chemistry
I have no idea where to start with this problem: A certain reaction has the following general form: aA > bB At a particular temperature and (A)o = 2.00(10^2)M, concentration versus time data were collected for this reaction, and a plot of In(A) versus time resulted in a ... 
Chemistry
At a given temperature, a firstorder reaction has a rate constant of 3.5 ´ 10–3 s–1. How long will it take for the reaction to be 24% complete? A chemical reaction that is firstorder in X is observed to have a rate constant of 2.20 ´ 10–2 s–1. If the initial ... 
AP Chem
A firstorder reaction has a rate constant of 0.547 min  1. How long will it take a reactant concentration 0.14 M to decrease to 0.07 M? Not sure how to do this! 
Chemistry
1. The following data was collected for the reaction between hydrogen and nitrogen monoxide. The time recorded corresponds to a N2 concentration change of 5.3 x 104 M. 2H2(g) + 2NO(g) 2H2O(g) + N2(g) Trial [H2], M [NO], M Time, s 1 0.01 0.02 74 2 0.02 0.02 37 3 0.01 ... 
Chemistry
The rate constant for this firstorder reaction is 0.440 s1 at 400 C. A to products How long in seconds would it take for concentration of A to decrease from 0.740 M 0.290 M? 
chemistry
The rate constant for this firstorder reaction is 0.320 s–1 at 400 °C. A> Products How long (in seconds) would it take for the concentration of A to decrease from 0.830 M to 0.220 M? 
MATH
what is a constant rate of change? That means the velocity changes over time in the same manner. 4,800 +3,700 =4,500 Rate of Change Is Constant You can increase or decrease the amount or concentration of a species by a constant value using a zero order rule. For example, the ... 
help please?!
If it takes 30 seconds for a reactant concentration to decrease from 1.0 M to 0.5 M in a firstorder chemical reaction, then what is the rate constant for the reaction? 
Chemistry
The rate constant for this first order reaction is 0.440s1at 400 C. A to products How long(in seconds) would it take for the concentration of A to decrease from 0.740 M to 0.290 M? 
Chem 132
The rate constant for this firstorder reaction is 0.650 s–1 at 400 °C. A> Products How long (in seconds) would it take for the concentration of A to decrease from 0.660 M to 0.350 M? 
chemistry
33) A firstorder reaction has a rate constant of 0.33 min1. It takes __________ min for the reactant concentration to decrease from 0.13 M to 0.088 M. A) 1.4 B) 0.13 C) 1.2 D) 0.85 E) 0.51 how can i set this up? 
chemistry
how do you solve this problem? consider the reaction A>B the rate of the reaction is 1.6 x 10^2 M/s when the concentration of A is 0.35 M. Calculate the rate constant if the reaction is a) first order in A and b) second order in A. 
chemistry
If it takes 30 seconds for a reactant concentration to decrease from 1.0 M to 0.5 M in a firstorder chemical reaction, then what is the rate constant for the reaction? A. 43 s–1 B. 0.046 s–1 C. 0.023 s–1 D. 0.033 s–1 
chemistry
The following data were obtained at 25° C for the reaction [1+2+2] C2H5Br + OH C2H5OH + Br Determine the rate law for the reaction from these data. [C2H5Br] [OH] Rate 0.150 0.200 4.8 x 105 0.300 0.200 9.6 x 105 0.450 0.200 14.4 x 105 0.300 0.600 28.8 x 105 (ii) The ... 
chemistry
Which of the following terms are present in the rate law? A. The rate constant, the concentration of the reactants, and the order of the reactants B. The rate constant and the concentration of the reactants C. The rate constant and the temperature of the reactants D. The rate ... 
chemistry help?!
Which of the following terms are present in the rate law? A. The rate constant, the concentration of the reactants, and the order of the reactants B. The rate constant and the concentration of the reactants C. The rate constant and the temperature of the reactants D. The rate ... 
science
Which of the following terms are present in the rate law? A. The rate constant, the concentration of the reactants, and the order of the reactants B. The rate constant and the concentration of the reactants C. The rate constant and the temperature of the reactants D. The rate ... 
chemistry
For the firstorder reaction A => 3 B + C, when [ A]0 = 0.014 mol·L1, the concentration of B increases to 0.017 mol·L1 in 2.7 min. (a) What is the rate constant for the reaction expressed as the rate of loss of A? I found this to be .1923, which I know is correct. (b) ... 
Chem8
The decomposition of XY is secondorder in XY and has a rate constant of 0.00895 M1s1 at a certain temperature. If the initial concentration of XY is 0.194 M, how long (in seconds) will it take for the concentration to decrease to 0.047 M? 
Chem10
The decomposition of XY is secondorder in XY and has a rate constant of 0.00599 M1s1 at a certain temperature. If the initial concentration of XY is 0.174 M, how long (in seconds) will it take for the concentration to decrease to 0.054 M? 
Chemistry
The first order rate constant is 1.87 x 10^3 min^1 at 37°C for reaction of cisplatin. Suppose the concentration of cisplatin in the bloodstream of a patient is 4.73 x 10^4 mol/L. Calculate the concentration exactly 24 hours later. 
science
the decomposition of h2o2 is first order reation following up the decom position it was found that the remaining h2o2 after 45 min was 15 units from the original concentration57.5 unit calculate the rate constant 
Chemistry
Hi I was hoping to get some help on this. It's review for my chemistry text on Monday and I would be grateful if someone could help me out. My teacher has been out for two weeks but we still have to know this material. 1. The following data was collected for the reaction ... 
chemistry
What would be the concentration of dinitrogen pentoxide after 6.00 X 10(2) seconds and how long would it take for the concentration of N2O2 to decrease to 10.0% of its initial value in the following equation... N2O5 to NO2 and O2 initial concentration is 1.65 X 102mol/L rate ... 
Chemistry
Determine the rate constant for each of the following firstorder reactions. In each case, write the rate law for the rate of loss of A. (a) 2 A B + C, given that the concentration of A decreases to onefourth its initial value in 57 min (b) 2 A B + C, given that A0 = 0.036 ... 
Chemistry
For the reaction 2 NO (g) + Cl2 (g) → 2 NOCl (g) If the concentration of NO is tripled, the rate of the reaction increases by a factor of nine. If the concentration of Cl2 is cut in half, the rate of the reaction is decreased to half the original rate. Find the order of ... 
Chemistry
A reaction of the form aA> Products is second order with a rate constant of 0.169 L/(mol*s). If the intial concentration of A is 0.159 mol/L, how many seconds would it taje for the concentration of A to decrease to 6.07X10^3 mol/L 
Chemisty
A reaction of the form aA> Products is second order with a rate constant of 0.169 L/(mol*s). If the intial concentration of A is 0.159 mol/L, how many seconds would it taje for the concentration of A to decrease to 6.07X10^3 mol/L 
Chemistry
Determine the rate constant for the following secondorder reaction: A=C+2D given that the initial concentration of A is .3 M and that the concentration of C increase to .01 M in 200 seconds. Express the result in terms of the rate law for the loss of A. 
Chemistry
Determine the rate constant for the following secondorder reaction: A=C+2D given that the initial concentration of A is .3 M and that the concentration of C increase to .01 M in 200 seconds. Express the result in terms of the rate law for the loss of A. 
chemistry kinetics
Decomposition of an organic compound A follows first order kinetics. Initial concentration of A is 2 M. If rate constant of the decomposition is 3.58 × 10^−6 min^1 , calculate the rate after 3 hours. 
Chemistry
1. The decomposition of acetaldehyde is a second order reaction with a rate constant of 4.71 × 10^−8 L/mol/s. What is the instantaneous rate of decomposition of acetaldehyde in a solution with a concentration of 5.55 × 10^−4 M? 2. The rate constant for the firstorder ... 
Chemistry
The reaction: 2 HI==> H2 + I2, is second order and the rate constant at 800 K is 9.70 x 102 M1 s1. How long will it take for 8.00 x 102 mol/L of HI to decrease to onefourth of its initial concentration? 
intergrated rate law chemistry
The decomposition of ammonia on a platinum surface at 1129 K occurs according to the following reaction: 2NH3 (g) ¨ N2(g) + 3H2(g). Use the following kinetic data which report the variation of ammonia concentration in the gas phase with time to evaluate the order of ... 
chemistry, chemical kinetics
I keep getting these questions wrong, could someone please help. Thanks so much. Question 1 For the following overall reaction, the rate constant is 3.4x10^2. A(g)+ 2B > 2C + D What may be the rate reaction? Question 2 The rate law for this reaction is R=k[NO][Cl2] ... 
Chemistry
The rate law of a reaction, A> B+C is given by the expression: Rate=k, where k=0.0113 mol/L min. If the initial concentration of the reactant is 0.225 mol/L, how long does it take for the concentration to decrease to 0.180 mol/L? I know i have to find the order of the ... 
chemistry
Determine the overall orders of the reactions to which the following rate laws apply: a. rate = k[NO2]^2 b. rate = k c. rate = k[H2][Br2]^1/2 d. rate = k[NO]^2[O2] I think the answers are: a. Second Order b. Zero Order c. First Order for H2 and Onehalf order for Br2 d. Second... 
Chemistry
Cyclpropane is converted to its isomer propylene, when heated. The rate law is first order in cyclopropane and the rate constant is 6.0X10^4/s at 500 degrees C. If the intial concentration of cyclopropane is 0.0226 mol/L, what is the concentration after 899s? 
Chemistry
Cyclpropane is converted to its isomer propylene, when heated. The rate law is first order in cyclopropane and the rate constant is 6.0X10^4/s at 500 degrees C. If the intial concentration of cyclopropane is 0.0226 mol/L, what is the concentration after 899s? 
Chemistry
Cyclpropane is converted to its isomer propylene, when heated. The rate law is first order in cyclopropane and the rate constant is 6.0X10^4/s at 500 degrees C. If the intial concentration of cyclopropane is 0.0226 mol/L, what is the concentration after 899s? 
Chemistry
what is the rate of a firstorder reaction that has a reactant concentration of 1.1M and a rate constant of 0.14/s? 
Chem1
The reaction N2O5 > NO3 + NO2 is firstorder in N2O5 and has a rate constant of 0.058/s. Calculate the rate of reaction when the concentration of N2O5 is 0.065. 
Chemistry
The halflife for the firstorder conversion of A to B is 56.5 hours. How long does it take for the concentration of A to decrease to 10.0% of its original amount? Our professor has given us the answer  188hr but I am not entirely sure how he got it. 
chemistry
The rate of a reaction A + 2B > products is determined. When the concentration of A is 1.0 M, the rate of the reaction is 0.50 M/s. When the concentration of A is 0.50 M, the rate is 0.25 M/s. From this data, you can determine: a. that the reaction is second order in A. b... 
chemistry
The isomerization reaction H3CNC(g) <=> H3CCN(g) was found to be first order in H3CNC. At 600 K, the concentration of H3CNC is 75% of its original value after 205 s. (a) What is the rate constant for this isomerization reaction at 600 K? (b) At what time will 33% of the ... 
Chemistry Lab
What would happen to the reaction rate of a solution if 10 mL or more of water is added? Will the reaction rate increase or decrease? The following reaction occurs without a change in the color 2A (g) + B2(g)  2AB (g) a) How could you monitor the concentration of the ... 
Chemistry Lab
What would happen to the reaction rate of a solution if 10 mL or more of water is added? Will the reaction rate increase or decrease? The following reaction occurs without a change in the color 2A (g) + B2(g)  2AB (g) a) How could you monitor the concentration of the ... 
Chemistry
Question: the rate constant for the second order decomposition of NOBr(g) is .800 1 divided by MS at 10 degree's C. Suppose a 2.50 L beaker contains NOBr at a concentration at .0680 moles per liter. How much time does it take for 75.0 percent of the sample to decompose. I know... 
Chemistry
Cyclopropane, C3H6, is converted to its isomer propylene, CH2=CHCH3, when heated. The rate law is first order in cyclopropane, and the rate constant is 6.0 10^4 /s at 500°C. If the initial concentration of cyclopropane is 0.0238 mol/L, what is the concentration after 719 s? 
Chemistry
Hydrogen iodide decomposition via a secondorder process to produce hydrogen and iodine according to the following chemical equation: 2 HI(g) > H2 (g) + I2 (g) If it takes 489 seconds for the initial concentration of HI to decrease from 0.0693 M to 0.0174 M, what is the ... 
chemistry
The rate constant of a firstorder reaction is 4.25 x 10^4 s^1 at 350 Celsius. If the activation energy is 103 kJ/mol, calculate the temperature at which its rate constant is 8.75 x 10^4 s^1. 
Chemistry
The gas phase reaction X+Y⇄ Z is first order in Y and second order in X. If the concentration of X is double and concentration of Y is tripled. The reaction rate would be increase by a factor of: then, Rate= k [x]^2[y] > k[x]^4[y}^3 is this the correct line of ... 
environmental engineering
A lake receives 8 m3/s of inflow containing 0.3 mol/m3 of a chemical. The chemical reacts with a first order rate constant of 0.01 h1. The outflow from the lake is also 8 m3/s. Assume there was no chemical in the lake at the beginning and volume of the lake is 106 m3. What ... 
gen chem
The rate constant of a first order reaction is 4.60 x 104 s1 at 350 oC. If the activation energy is 104 kJ/mol, calculate the temperature in Kelvin at which its rate constant is 1.80 x 103 s1. 
chemistry
A student performed two sidebyside reactions to test the decomposition of N2O5. The only difference between the two reactions was reactant concentration — reaction 1 started with 2 M N2O5 and reaction 2 started with 1.2 M. Which of the following statements would be true of... 
Chemistry
The reaction: 2 HI==> H2 + I2, is second order and the rate constant at 800 K is 9.70 x 102 M1 s1. How long will it take for 8.00 x 102 mol/L of HI to decrease to onefourth of its initial concentration? can someone please show me how to set this up? 
Chemistry
The following rearrangement reaction is first order: C3H6 ¨ CH3CH=CH2 The rate constant for this reaction is 6.7 ~ 10−4. How many minutes will it take for the concentration of C3H6 to drop to 11.75% of its initial value? How do I calculate this step by step. My ... 
Chemistry
The reaction OH + NH4+ = H20 + NH3 is kinetically first order in both reactants' concentrations. The rate constant is 2e10 1/M s. If 50 ml of .01 M NaOH is mixed with 50 ml of .01 M NH4CL, find the time required for the OH concentration to reach 1e4 M. 
chemistry
The first order rate constant for the decomposition of N2O2 of 0Cis 5.2*10/6 per minute. If the activation energy is 6200J/mol, calculate the rate constant at 25C 
chem
H2o2+3i+2h > I3+2H2o In the first 10.0 second of the reaction the concentration of I dropped from 1.000M to 0.868M a) calculate the average rate of reaction for iodine in this time interval. b) Determine the rate of change in the concentration of H during this time ... 
Chemistry
Cyclopropane is converted to propene in a firstorder process. The rate constant is 5.4 × 102 hr1. If the initial concentration of cyclopropane is 0.150 M, what will its concentration be after 22.0 hours? 
Chemistry
The rate constant for a certain reaction is = 4.30×10−3 s^1. If the initial reactant concentration was 0.400 M , what will the concentration be after 19.0 minutes? Rate would be first order therefore I used. A=A initial*e^kt I keep getting .0030 M but supposely I am ... 
Chemistry
A reaction is first order and it takes 324 minutes for the reaction to be 50.0% complete. How long will it take for the reaction to be 85.0% complete at the same temperature? 2. N2O5 decomposes to N2O4 and O2 and the reaction is first order in N2O5 with a specific rate ... 
Chemistry
The decomposition reaction of A to B has a rate constant of 0.00923 M1s1: A → 2B If the initial concentration of A is 0.160 M, how long will it take for the concentration of A to decrease by 68.2%? 
PChem
For the gas phase reaction 2NO2 + F2 ¨ 2NO2F, the rate constant is k= 38 dm3/mols at 27 oC. The reaction is firstorder in NO2 and firstorder in F2. A) Calculate the number of moles of NO2, F2, and NO2F after 10.0 s if 2.00 mol of NO2 is mixed with 3.00 mol of F2 in a 400... 
Chemistry
Consider the reaction A ==> B. If the reaction is firstorder in A with the initial concentration A being 6.048M, what is the concentration of A after 1.986 seconds if the rate constant is 0.483s1? Error tolerance: ±0.5% Can someone explain how to do this? Thanks ln(Ao/A... 
chemistry
1) The activation energy of a certain reaction is 35.3 kJ/mol. At 20 degrees C, the rate constant is 0.0130 s^1. At what temperature would this reaction go twice as fast? Answer in units of degrees Celsius. i think the answer is around 34, but i keep in getting it screwed up... 
Chemistry
Calculate the halflife (in s) of a firstorder reaction if the concentration of the reactant is 0.0655 M 18.4 s after the reaction starts and is 0.0173 M 41.2 s after the reaction starts. I got 25.6 Suppose the halflife is 23.7 s for a first order reaction and the reactant ... 
chemistry
The decomposition of an aldehyde solution in carbon tetrachloride is a first order reaction with a rate constant of 1.20 x 103 minl. If we start with [aldehyde] = 0.0500 molar, what will the concentration be 150 minutes later? a. 0.00900 M b. 0.0418 M c. 0.00926 M d. 0.... 
Chemistry
I'm supposed to calculate the rate equation, including k, for the reaction whose data is given in the table: Experiment: 1 2 3 Initial Concentration X: 0.10, 0.10, 0.60 Initial Concentration Y: 0.20, 0.10, 0.10 Measured Initial Rate: 2.57, 1.25, 1.27 (I hope the formatting ... 
Chemistry
Cyclopropane rearranges to form propene: CH2CH2CH2 > CH2=CHCH3 by firstorder kinetics. The rate constant is k = 2.74 x 103 s1. The initial concentration of cyclopropane is 0.290 M. What will be the concentration of cyclopropane after 100 seconds? 
College Chemistry
The following data are obtained for the decomposition of N2O5 at a certain temperature: 2N2O5(g)↔4NO2(g) + O2(g) Time(s) 0 200 400 600 800 N2O5 (atm) 2.10 1.85 1.63 1.43 1.26 Find the rate constant kobs for this firstorder decomposition reaction in sec1 So far I have ... 
CHEMISTRY
A secondorder reaction has a rate constant of 1.65 M–1 s–1. If the initial reactant concentration is 1.0 M, calculate the time (in seconds) required for the reaction to become 90% complete. i got 0.06734 seconds but that's incorrect i have no idea what i am doing wrong! ... 
Chemistry
A first order reaction ABC → AB + C has a rate constant of 0.0125 /s. If the initial concentration of ABC is 0.500 M, what is the concentration of ABC after 5 minutes? Note: do not include units in your answer, do not use scientific notation. 
Chemistry
The following reaction is first order, C2H6==> 2CH3. If the rate constant is equal to 5.5 x 104 s^1 at 1000 K, how long will it take for 0.35 mol of C2H6 in a 1.00 L container to decrease to 0.20 mol in the same container? Thank you very much 
chemistry
In a reaction A to products, ,4.40 min after the reaction is started concentration of A is 0.588M. The rate of reaction at this point is rate= change in concentration of A/change in time=2.2x10^2Mmin^1. Assume that this rate remains constant for a short period of time. A. ... 
Chemistry
What additional information would be needed to calculate the rate in units of concentration per time? 
college chemistry
After 94.995 seconds the concentration of A was reduced from 0.3688 M to 0.1464 M. What is the first order rate constant? 
Chemistry
The rate equation for the hydrolysis of sucrose to fructose and glucose is first order. After 27 minutes the sucrose concentration decreased from 0.0146M to 0.0132M. Find the rate constant K. Please help me! 
Chemistry
Determine the rate constant for each of the following secondorder reactions. In each case, express your results in terms of the rate law for the loss of A. (a) 2 A B + 2 C, given that the concentration of A decreases from 2.74 mmol·L1 to 1.46 mmol·L1 in 122 s. (b) A C + 2... 
Concentration and Reaction
The rate of the following reaction: Radioactive decay of 90Sr, is characterized by the rate constant k = 0.024 year1. What is the halflife (in years) for this reaction at the same conditions when the initial concentrations are 0.0356 M? (Round your answer to 3 significant ... 
Chemistry
Consider the following equilibrium process at 686 C C02(g)+H2(g)=CO(g)+H20(g) The equilibrium concentration of the reacting species are [CO]=0.050M, [H2]=0.045M, [CO2]=0.086M, and [H20]=0.040M. (a)Calculate the Kc for the reaction at 686 C. (b) If we add CO2 to increase its ... 
Chemistry
Dinitrogen pentoxide, N2O5, decomposes by firstorder kinetics with a rate constant of 0.15 s1 at 353 K. (a) What is the halflife (in seconds) for the decomposition of N2O5 at 353 K? (b) If [N2O5]0 = 0.0579 mol·L1, what will be the concentration of N2O5 after 4.0 s? (c) ... 
Chemistry
Dinitrogen pentoxide, N2O5, decomposes by firstorder kinetics with a rate constant of 0.15 s1 at 353 K. (a) What is the halflife (in seconds) for the decomposition of N2O5 at 353 K? (b) If [N2O5]0 = 0.0579 mol·L1, what will be the concentration of N2O5 after 4.0 s? (c) ... 
College Chemistry (DrBob222)
The decomposition of HCO2H follows firstorder kinetics. HCO2H(g) CO2(g) + H2(g) The halflife for the reaction at a certain temperature is 44 seconds. How many seconds are needed for the formic acid concentration to decrease by 73%?