# Chemistry - Concentration and Time

88,957 results

CHEMISTRY
a concentration-time study of the gas phase reaction a 2A3 -> 3A2 produced the data in the table below. time [A3] (M) [A2] (M) 0 4.00 *10^-4 0 10 2.00 *10^-4 3.00 *10^-4 20 1.00 *10^-4 4.50 *10^-4 10 5.00 *10^-5 ? A) What is the concentration of A2 in the time interval 20-...

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
a compound decomposes with half life of 8seconds and is independent of concentration.how much time is consumed to convert the concentration of one sixteenth of its initial concentration?

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. ...

CHEM
a concentration-time study of the gas phase reaction a 2A3 -> 3A2 produced the data in the table below. Time (s) [A3] (M) [A2] (M) 0 4.00 × 10–4 0 10 2.00 × 10–4 3.00 × 10–4 20 1.00 × 10–4 4.50 × 10–4 30 5.00 × 10–5 A) What is the concentration of A2 in ...

chemistry
The initial concentration of the a substance was 1.95 M. After 27.72 hours the concentration was 0.9750 M. After anothers 55.44 hours the concentration was 0.4875 M (total time = 83.16 hours). If another experiment were conducted in which the initial concentration was 0.427 M...

Chemistry - Concentration and Time
1. How is the rate affected by doubling the concentratino? 2. Explain the effect of concentration on the rate of a reaction in terms of the "Collision Theory" of chemical reactions. 3. Considering that 1/Time is proportional to the rate of the reaction how is the rate of the ...

Chemistry
calculate the natural logarithm and reciprocal concentration at 0 seconds and NO2 concentration (M) of .8333 and at time 20 (seconds) and .4617 NO2 concentration (M)

chemistry
In a reaction, a chemist is observing the absorbance of CoCl2(aq) as a function of time to determine the rate at which it is being consumed in a reaction. At time t=10 s, the chemist determines that the concentration of CoCl2(aq) is 0.12 M. At time t=20 s, the chemist ...

chemistry
The first-order 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. one-third of its initial concentration h

calculus
c(t) = t^3 * 2^(-t/2) Find the initial concentration c(0) at time t=0 min. Finds the maximum concentration of the dye sand the time when this occurs.

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 10-2mol/L rate ...

chemistry
Can someone explain this to me? In the reaction: --> AgCl(s)<_______ Ag+(aq) + Cl-(aq) the shorter arrow pointing to the right shows that the qe. mixture consists mostly of ______. ---> In the reaction HC2h302 + H20<_______ H30+ + C2h302-, when the concentration of...

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/Math
Write a differential equation describing a second order reaction – a reaction in which the rate of depletion of the concentration of the reactants depends on the square of reactants’ concentration. Solve this differential equation and hence find an expression for the ...

Math
A mathematical model for concentration of administered cortisone in humans over a 24-hour period uses the function C= [(D x a) / V(a-b)] (e^(-bt)-e^(-at) where C is the concentration, D is the dose given at time t=0, V is the volume of distribution (volume divided by ...

chemistry
A) Calculate the hydrogen-ion concentration of a 5.45*10^-4 M H2CO3, solution, noting that Ka is bigger than Kb. B)What is the concentration of CO3^2-? after finding the concentration to A), do i use that concentration (M) as the initial M for CO3^2-? thanks in advnace

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
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 10-2mol/L rate ...

more chemistry this time concentration
Some of the problems. I honestly have no clue how to do these/where to look for answers. What is the concentration of 5.28*10^14 Carbon Tetrachloride molecules dissolved in 149 mL of water? How many grams of Carbon Dioxide will there be in a 16.43 mL of a .03M solution.

Chemistry
The half-life for the second-order 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

Calc
Write a deferential equation describing the given situation. The rate at which the concentration of a drug in the bloodstream decreases is proportional to the concentration. Let Q(t) be the concentration of the drug at any time t and k be a positive constant. dQ/dt = ? THANKS!!!

Chemistry
A sample of ammonia gas was allowed to come to equilibrium at 400 K. 2NH3(g) --> N2(g) + 3H2(g) At equilibrium, it was found that the concentration of H2 was 0.0584 M, the concentration of N2 was 0.0195 M, and the concentration of NH3 was 0.430 M. What was the initial ...

Chemistry
At 2000 ∘C the equilibrium constant for the reaction 2NO(g)←−→N2(g)+O2(g) is Kc=2.4×103. The initial concentration of NO is 0.220M . What is the equilibrium concentration of NO? What is the equilibrium concentration of N2? What is the equilibrium ...

polynomials & rational function
A drug is administered to a patient and the concentration of the drug in the bloodstream is monitored. At time t >= 0(in hours since giving the drug) the concentration is given by(in mg/L) c(t) = 5t / (t^2+1) Graph the function. From the graph, how do I find a)the highest ...

chemistry
the concentration of a chemical degrades in water according to order kinetics. the degradation constant is 0.2 day^-1. if the initial concentration is 100.0 mg/L, how may days are required for the concentration to reach 0.14 mg/L?

Calculus
The blood alcohol concentration after a drink has been consumed can be modelled by c(t)=(0.02t)e^(−0.05t) where t is the time in minutes elapsed after the consumption of the drink and c(t) is the concentration in mg/mL at t. At what time in the first hour after consuming...

chemistry
*This is part of an exam. so please don't give full solution* just trying to bump ahead of a block. The decomposition of NO2 at room temperature exhibits the following variation in concentration with time: The concentration of NO2 is expressed in mol/liter, while time is ...

Chemistry
2A-->B+C given that the initial concentration of A is .022M and that at 69 s, the concentration of B increases to .0095M, what is the rate constant? i know I need to find the new concentration of A at 69s, but I am having trouble with findthing this. I thought it might be ...

The ionization constant of HA is 4.0e-4. Using the ice table what is the equilibrium concentration of HA in terms of its initial concentration and x? HA(aq) + H2O(l) = H3O^+^(aq) + A^-^(aq) I 0.040M OM OM C -X +x +x E ? x x I thought that to find the concentration you need to ...

Chemistry
How would you get the concentration(ppm) of a sample from absorbance? Absorbance of standard = 2.55 Absorbance of sample = 2.31 Wavelength of machine 345nm slit lenght = 1cm time = 2s The metal being tested is Copper and the concentration of the standard is 8ppm.

chemistry
i have difficulties in this question.any help would be appreciated. 1) 2No(g)-> N2(g)+O2(g) at 1800K,K is 8.36*10^3.what concentration of NO(g) is in equilibrium with N2(g) at a concentration of 0.0500mol/liter and O2(g) at a concentration of 0.500 mol/liter?

College Chemistry
For my homework I got this problem that my professor never went over in class how to do it and I don't know how to interpret it. A chemist runs a second order reaction of A->B starting at 10mili moles/L concentration of A (and no B). After one hour the concentration of the ...

College Chemistry
For my homework I got this problem that my professor never went over in class how to do it and I don't know how to interpret it. A chemist runs a second order reaction of A->B starting at 10mili moles/L concentration of A (and no B). After one hour the concentration of the ...

College Chemistry
For my homework I got this problem that my professor never went over in class how to do it and I don't know how to interpret it. A chemist runs a second order reaction of A->B starting at 10mili moles/L concentration of A (and no B). After one hour the concentration of the ...

Chemistry
If a solution of Ca(OH)2 has a pH of 12.31 how can I calculate the concentration of calcium hydroxide in mol L-1 ? Write the dissociation equation: Ca(OH)2 >>Ca+ + 2OH So the concentration of the OH ion is twice the Ca(OH)2 . Find the concentration of the OH ion [H+]= ...

Chemistry
You wish to increase the carbon content of a slab of steel by exposing it to a carburizing atmosphere at elevated temperature. The carbon concentration in the steel before carburization is 235.0 ppm and is initially uniform through the thickness of the steel. The atmosphere of...

Chemistry
consider the reaction: N2(g) + O2 (g) --> 2NO (g) removing some of the N2(g) will_____ A) increase the concentration of O2 B) decrease the concentration of O2 C) increase the concentration of NO(g)

chemistry
What would be the final concentration of [K+] if we mix 0.234 L of a solution with a concentration of 1.2M K2CO3 with 312.5 mL of a solution with a concentration of 0.32 M K3PO4

chemistry
Need some help. have the A part of the question but do not know how to set B or C. Butadiene (C4H6) reacts with itself to form a dimer with the formula C8H12. The reaction is second order in butadiene. If the rate constant at a particular temp is 0.04/(M s) and the initial ...

Chemistry
I have discovered a new chemical compound with the formula A2B. If a saturated solution of A2B has a concentration of 4.35x10-4M. a) What is the concentration of B2- ions? b. What is the concentration of A1+ ions? c. What is the solubility product constant for A2B? Can you ...

The initial concentration of a reactant in a first order reaction is 0.620 molar. What will be its concentration after 3 half-lives? I did 0.620 -> 0.31 ->0.155 0.155M will be the concentration. Is this correct?

Biotech
The dynamic method is used to measure kLa in a fermentor operated at 30degC. Data for dissolved-oxygen concentration as a function of time during the re-oxygenation step is given (table with time (s) and CAL (% air saturation)). The equilibrium concentration of oxygen in the ...

Chemistry
I need help with a concentration question. I need to know how to calculate the product with the higher concentration. \$6.50 for 185 mL and the concentration of the active ingredient is 0.005% OR \$7.00 for 165mL and the concentration of the active ingredient is 0.700%. I need ...

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
A solution with pH = 4 has 1. relatively high concentration of OH- 2. relatively low concentration of H3O+ 3. relatively high concentration of H3O+ 4. zero concentration of OH- Some of the answers people are giving me are confusing. I just need to know if it 1,2,3 or 4?

Chemistry
Hey there! I have these two questions for my chemistry class, and I am a little confused on how I should go about solving them. If someone could give me the steps necessary to solve these problems I would be most appreciative. 1.) p-Toluenesulfinic acid undergoes a second-...

CHEMISTRY
A solution of H2SO4(aq) with a molal concentration of 1.94m has a density of 1.119g/mL. What is the molar concentration of this solution? I got an answer of 2.17 M and it is incorrect..please help. My work: So Molar concentration = molal concentration * density = 1.94 mol/kg...

Chemistry
1. In the lab you will be provided with 0.1 M sodium hydroxide that you will standardize using KHP. What is implied by writing the NaOH concentration as 0.1 M? a) After performing your standardization and calculations, any deviation from 0.1000 M is due to experimental error. ...

chemistry
A(g)+ B(g) <---> C(g) + D(g) Kc= 144. If .4 mol of A and B are placed in a 2 Liter container, what will be the concentration of C at equilibrium? I said the concentration of A= .2 because (.4/2=.2) and because 1 mol of A = 1 mol of C, the concentration of C also = .2 But...

chemistry
A(g)+ B(g) <---> C(g) + D(g) Kc= 144. If .4 mol of A and B are placed in a 2 Liter container, what will be the concentration of C at equilibrium? I said the concentration of A= .2 because (.4/2=.2) and because 1 mol of A = 1 mol of C, the concentration of C also = .2 But...

Chemistry
The following reaction was monitored as a function of time: AB--->A+B A plot of 1/[AB] versus time yields a straight line with slope 5.2×10−2 . If the initial concentration of is 0.240M , and the reaction mixture initially contains no products, what are the ...

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
What happens to the hydroxide ion concentration in aqueous solutions when we increase the hydrogen ion concentration by adding an acid? Would it be good enough to answer by stating that the OH- ion concentration decreases, lowering the pH?

College Chemistry
For my homework I got this problem that my professor never went over in class how to do it and I don't know how to interpret it. A chemist runs a second order reaction of A->B starting at 10mili moles/L concentration of A (and no B). After one hour the concentration of the ...

chemistry
The carbon concentration in the steel before carburization is 366.5 ppm and is initially uniform through the thickness of the steel. The atmosphere of the carburizing furnace maintains a carbon concentration of 8040.0 ppm at the surface of the steel. Calculate the time ...

chemistry 30 concentration of a product
calculate the concentration of the products of the following equilibrium when the equilibrium constant is 12.3 and the equilibrium concentration of nobr2 is 2.17 mol/l

chemistry
Given: 2so2 + o2 -> 2so3 + 44kcal Which change increase the concentration of so4? a. increasing temperature b. increasing the concentration of o2 c. decreasing the pressure d. decreasing the concentration of so2

Chemistry
1. How is the rate affected by doubling the concentratino? 2. Explain the effect of concentration on the rate of a reaction in terms of the "Collision Theory" of chemical reactions. 3. Considering that 1/Time is proportional to the rate of the reaction how is the rate of the ...

Chemistry
consider the equation for the following reaction at equilibrium. X+Y<-->2Z+heat the concentration of the product could be increased by 1.adding a catalyst 2.adding more heat to the system 3.increasing the concentration of Y 4.decreasing the concentration of X

Chemistry
You are given a compound with an unknown concentration and you have five samples with known concentration of the compound. List 3 pieces of information you need to determine in order to calculate the unknown concentration spectrophotometrically.

Chemistry
1. In an equilibrium, A + B ---> C + D; "A" & "B" are mixed in a vessel at temperature "T". The initial concentration of "A" was twice the initial concentration of "B", & after the equilibrium has reached, concentration of "C" was twice the equilibrium concentration of "B...

Chemistry
Calculate the thiocyanate concentration at equilibrium if the irone (III) ion concentration is 0.23 M and the complex ion concentration is 0.625 M t equilibrium. Keq= 138M^-1

Chemistry
Calculate the thiocyanate concentration at equilibrium if the irone (III) ion concentration is 0.23 M and the complex ion concentration is 0.625 M t equilibrium. Keq= 138M^-1

chemistry
Calculate the thiocyanate concentration at equilibrium if the irone (III) ion concentration is 0.23 M and the complex ion concentration is 0.625 M t equilibrium. Keq= 138M^-1

Chemistry``
A substance (CD) decomposes into C and D. CD(g)  C(g) + D(g) At the temperature of the experiment, 15.0 percent of CD is decomposed when equilibrium is established. a) If the initial concentration of CD is 0.200 mol/L, what are the equilibrium concentrations of...

chemistry
what is the relationship between reaction rate and shape of equilibrium graph in relation to concentration vs time?

Chemistry
What additional information would be needed to calculate the rate in units of concentration per time?

Chemistry
I had to perform an experiment for rate of reaction. The point of the experiment was to show how changes in reactant concentration, temperature, and catalyst presence can affect the rate of a reaction. The reaction that we studied was H2O2 + 2I^- + 2H^+ -> I2 + 2H2O We had ...

chemistry
Q: Calculate the unknown molar concentration of CH3NH2 in MeOH titrated against a known molar concentration of HCl ? Could you please answer this, there are lots of examples around calculation PH of two known's but not so much of unknown concentration. thankyou.

Chemistry
The bubble in the tip of the buret is not removed prior to performing the NaOH standardization. Will the reported concentration of the NaOH be greater than, less than, or equal to the true concentration of the NaOH if the bubble is flushed from the buret during the titration? ...

Chemistry
you are given the equation S2O3 + 2H --> S + SO2 + H2O you mix 25 ml of HCl with a concentration of 2 mol/L with 5 mL of Na2S2O3 with a concentration of 0.3 mol/L. what is the concentration of S2O3 and H?

Chemistry
After taking a medication its concentration in the bloodstream behaves as shown in the graph 650t/(t^3+200), where the x values are hours since first taking the medication and y is the concentration of the medication (mg/cc) in the blood stream after the given number of hours...

Chemistry
After taking a medication its concentration in the bloodstream behaves as shown in the graph 650x/(x^3+200), where the x values are hours since first taking the medication and y is the concentration of the medication (mg/cc) in the blood stream after the given number of hours...

chemistry
what is the relationship between reaction rate and shape of equilibrium graph in terms of concentration versus time?

Chemistry
You wish to increase the carbon content of a slab of steel by exposing it to a carburizing atmosphere at elevated temperature. The carbon concentration in the steel before carburization is 359.5 ppm and is initially uniform through the thickness of the steel. The atmosphere of...

chemistry
Suppose you have the following reaction at equilibrium: N2(g) + 3H2(g) = 2NH3(g), ΔH = −22 kcal/mol What changes are expected to occur if the temperature of the system was decreased. You may select multiple answers. The concentration of NH3(g) would decrease The ...

chemistry
If a saline solution has a concentration of 0.25 g per mL, calculate the following. a) The concentration of this solution in %w/v. b) The concentration of this solution in grams per litre (g/L). c) The concentration of this solution in milligrams per mL (mg/mL).

Chemistry
In a solution of a weak acid and its conjugate base, which condition has to be true for pH to equal pKa? The concentration of acid has to be greater than the concentration of base. The concentration of acid has to be equal to the concentration of base. An indicator has to be ...

Chemistry
In a given 1st order reaction A ---> products, the initial concentration of A is 0.40 M. What will be the concentration of A after 15 seconds if the half-life of the reaction is 3 seconds? I found the concentration to be 1.25 x 10-2 M But then how do I find the rate ...

Chemistry
Recall that all aqueoous solutions contain_____. Water can also undergo ____. This process is called the ______of water. The reaction can be written as: Notice the double arrow in the reaction. This indicates that the reaction is_____. However, only a tiny fraction of water ...

Chemistry
Determine the average rate of change of B from t=0s to t=352s. A to 2B Time Concentration of A (M) 0 0.670 176 0.385 352 0.100

Chemistry
This question was posted: At 22 °C an excess amount of a generic metal hydroxide M(OH)2, is mixed with pure water. The resulting equilibrium solution has a pH of 10.56. What is the Ksp of the compound at 22 °C? I have found my [OH-] concentration (3.63x10^-4) but I am ...

chemistry
what would be the final concentration if you incorporate 11m: of 29'' concentration of HF to 800mL of water?

chemistry
how do I plot absorbance vs concentration and transmittance %T vs concentration on the same graph??

Chemistry
If 27.0 mL of Ca(OH)2 with an unknown concentration is neutralized by 32.40 mL of 0.185 M HCl, what is the concentration of the Ca(OH)2 solution?

chemistry
In adsorption, what is bulk concentration? How does that differ from initial concentration? Thanks in advance.

chemistry
A 965 solution is diluted to a volume of 1.10 and a concentration of 8.00 . What was the initial concentration?

Chemistry
to increase the carbon content of a slab of steel by exposing it to a carburizing atmosphere at elevated temperature. The carbon concentration in the steel before carburization is 200.5 ppm and is initially uniform through the thickness of the steel. The atmosphere of the ...

Chemistry
A solution of H2SO4 with a modal concentration 6.25m has a density of 1.300 g/ml. What is the molar concentration?

college chemistry
Calculate the equilibrium concentration of H3O+ in the solution if the initial concentration of C6H5COOH is 6.0×10^-2. Kc=6.3 *10^-5

Chemistry
A sample of Hydrochloric Acid (HCl) has a concentration of 5.00 %(m/v). Determine the molar concentration of the solution.

chemistry
The concentration of saturated NaOH is 50.0% w/w and the density is 1.52 g/mL. If exactly 8.50 mL were diluted to 1.000 L, what would be the concentration?

chemistry
Hydro chloric acid is usually purchased on the concentration of 36.5% . Why it is not obtained in 100% concentration?

Chemistry
Calculate the H+ concentration (M), the OH- concentration and the number of H+ and OH- per litre in solutions having pH value of 2.73

Science help!!!!
Passive transport involves movement of substances. A. from areas of lower concentration to area of higher concentration B. from areas of higher concentration to areas of lower concentration C. from areas in which the concentration has reached a balance D. from areas of ...

Chemistry
Dinitrogen pentoxide, N2O5, decomposes by first-order kinetics with a rate constant of 0.15 s-1 at 353 K. (a) What is the half-life (in seconds) for the decomposition of N2O5 at 353 K? (b) If [N2O5]0 = 0.0579 mol·L-1, what will be the concentration of N2O5 after 4.0 s? (c) ...

Chemistry
Dinitrogen pentoxide, N2O5, decomposes by first-order kinetics with a rate constant of 0.15 s-1 at 353 K. (a) What is the half-life (in seconds) for the decomposition of N2O5 at 353 K? (b) If [N2O5]0 = 0.0579 mol·L-1, what will be the concentration of N2O5 after 4.0 s? (c) ...

College Algebra
The concentration C of a certain drug in a patient's bloodstream t minutes after injection is given by C(t)=50t/t^2+25. Determine the time at which the concentration is highest. Round your answer to the nearest tenth of a minute.

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