Recent questions tagged physical-chemistry

Assuming $ 100\%$ ionization , the increasing order of the freezing point of the solution will be

asked Aug 5, 2014 by meena.p

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A solution contains $0.1 \; mol$ of acetamide in 1L of glacial acetic acid . When the solution is cooled , the first crystals that appeared at the freezing point contain the molecules of

asked Aug 5, 2014 by meena.p

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For an ideal solution containing a nonvolatile solute, Which of the following expression is correctly represented?

asked Aug 5, 2014 by meena.p

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The freezing point of equimolal aqueous solution will be highest for

asked Aug 5, 2014 by meena.p

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Which of the following $0.1 \;M$ aqueous solution will have the lowest freezing point ?

asked Aug 5, 2014 by meena.p

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When mercuric iodide is added to an aqueous solution of potassium iodide the

asked Aug 5, 2014 by meena.p

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$5 g$ of a nonvolatile compound (molar mass $50\; g \;mol^{-1}$) is added to 100 g of water . If the decrease of pressure is $11.31$ Torr, the vapour pressure of water will be

asked Aug 5, 2014 by meena.p

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The vapour pressure of a solvent is found to be $400 mm$ Hg at $300 K$ When a certain amount of nonvolatile solute added to $50\;mol$ of the solvent its vapour pressure decreases to $360\;mm Hg$. The amount of solute added is:

asked Aug 5, 2014 by meena.p

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For the reaction $A+B \rightarrow C+D$, calculate the value of k for this reaction based on the following data collected in three different experiments:

asked Jul 25, 2014 by balaji.thirumalai

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The activation energy for a certain reaction is 76.7 kJ mol$^{-1}$. How many times faster will the reaction occur at 50$^\circ$C compared to 0$^\circ$C?

asked Jul 25, 2014 by balaji.thirumalai

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Calculate the value of k for this reaction based on the following data collected in three different experiments:

asked Jul 25, 2014 by balaji.thirumalai

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The rate constant of a reaction at 32$^\circ$C is 0.055 s$^{-1}$. If the frequency or pre-exponential factor is 1.2 $\times$ 10$^{13}$ s$^{-1}$, what is the activation energy?

asked Jul 25, 2014 by balaji.thirumalai

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If a temperature increase from 20$^\circ$C to 35$^\circ$C triples the rate constant for a reaction, what is the value of the activation barrier for the reaction?

asked Jul 25, 2014 by balaji.thirumalai

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The rate constant (k) for a reaction was determined as a function of temperature. A plot of $ln\; k$ versus $ \large\frac{1}{T}$ (in $K$) is linear and has a slope of $-1.01 \times 10^{4}\;K$. Calculate the activation energy for the reaction.

asked Jul 25, 2014 by balaji.thirumalai

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A certain reaction is first order, and 540 s after initiation of the reaction, 32.5% of the reactant remains. At what time after initiation of the reaction of the reaction will 10% of the reactant remain?

asked Jul 25, 2014 by balaji.thirumalai

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A certain first order reaction is 45% complete in 65 seconds. Determine the rate constant and the half-life for this process.

asked Jul 25, 2014 by balaji.thirumalai

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Calculate half-life for first-order reaction if 68% of a substance is reacted within 66 s.

asked Jul 25, 2014 by balaji.thirumalai

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What is the rate of a reaction if $[A]_o = 560\;M$, $[B]_o = 0.2\;M$, and 2nd order rate constant is $0.1\;M^{-1}s^{-1}$?

asked Jul 25, 2014 by balaji.thirumalai

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What is the concentration of $A$ at time $45\;s$ if $[A]_o = 1\;M$, $[B]_o = 45\;M$, and 2nd order rate constant is $0.6\;M^{-1}s^{-1}$?

asked Jul 25, 2014 by balaji.thirumalai

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If $[A] = 55\;M$ at $39s$, $[A]_o = 99\;M$, and $[B]_o = 1000\;M$, what is the 2nd order reaction rate constant?

asked Jul 25, 2014 by balaji.thirumalai

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The rate constant for the 2nd order reaction shown below is $0.54 M^{–1}$ at 300$^{\circ}$ C. How many seconds would it take for the concentration of NO$_s$ to decrease from $0.62\; M$ to $0.28\; M$?

asked Jul 24, 2014 by balaji.thirumalai

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The thermal decomposition of phosphine to phosphorus and hydrogen gas is a first order reaction, with a half-life of 35 s at 680$^\circ$C. Calculate the time required for 95% of phosphine to decompose.

asked Jul 24, 2014 by balaji.thirumalai

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The thermal decomposition of N$_2$O$_5$ to form NO$_2$ and O$_2$ is a first order reaction. The rate constant for the reaction is $5.1x10^{–4}s^{-1}$ at $318^{\circ} K$. Calculate the half-life of this reaction.

asked Jul 24, 2014 by balaji.thirumalai

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The following data was collected in three different experiments:

asked Jul 24, 2014 by balaji.thirumalai

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Calculate the value of k for this reaction based on the following data collected in three different experiments:

asked Jul 24, 2014 by balaji.thirumalai

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Consider the following reaction:$ A + 3 B \rightarrow 2 C + 2 D$. In one experiment, the rate of change of B was found to be $2.50 \times 10^{–4}\;M/s$. What is the rate of change of C in this experiment?

asked Jul 24, 2014 by balaji.thirumalai

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A certain first order reaction proceeds through t first order kinetics. The half-life of the reaction is 180 s. What percent of the initial concentration remains after 900s?

asked Jul 24, 2014 by balaji.thirumalai

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The decomposition of $N_2O_5$ is given by the following equation: $2\; N_2O_5\; (g) \rightarrow 4 NO_2\;(g) + O_2\;(g)$ At an initial $[N_2O_5]_0 = 3.15\; M$, the initial rate of reaction is $5.45 \times 10^{-5} \;M/s$ and when $[N_2O_5]_0 = 0.78\; M$, the initial rate of reaction is $1.35 \times 10^{-5}\; M/s$. What is the rate constant of this reaction?

asked Jul 24, 2014 by balaji.thirumalai

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The reaction $A \rightarrow \text{Products}$ is second order in $A$. Initially $[A]_0 = 1.00 M$ and after $25 \; \text{mins}, \;[A] = 0.25\; M$. What is the rate constant for this reaction?

asked Jul 24, 2014 by balaji.thirumalai

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From the integrated rate law for a first order reaction, $ [A] = [A]_0\; e^{-kt}$. Suppose rate constant, $k = 2.95 X 10^{-3} s^{-1}$, What percent of $A$ remains after $150 \;s$?

asked Jul 24, 2014 by balaji.thirumalai

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An elementary reaction, $2 A + C \rightarrow D$ , is second order in $A$ and first order in $C$. The rate of this reaction is $2.5 \times 10 ^{-1}1\; M/s$ when the concentrations of $A$ and $C$ are all $3.00\; mM$. What is the rate constant for the reaction?

asked Jul 24, 2014 by balaji.thirumalai

1 answer