4. The rate constant for the first-order decomposition of a compound A in the reaction 2AP is k = 2.78 x 10-7 s1 at 25°C. What is the half-life of A? What will be the pressure, initially 32,1kPa at (a) 10 s, (b) 10 min after initiation of the reaction? (6)

Sucrose, a sugar, decomposes in acid solution to give glucose and fructose. The reaction is first-order in sucrose, and the rate constant at 25 C is k = 0.21 h1. If the initial concentration of sucrose is 0.010 mol/L, what is its concentration after 5.0 h?

When boron trifluoride reacts with ammonia, the following reaction occurs: BF3(g)+NH3(g)BF3NH3(g)The following data are obtained at a particular temperature: (a) What is the order of the reaction with respect to BF3, NH3, and overall? (b) Write the rate expression for the reaction. (c) Calculate k for the reaction. (d) When [ BF3 ]=0.533M and NH3=0.300M, what is the rate of the reaction at the temperature of the experiment?

Regular ?ights of supersonic aircraft in the stratosphere ale of concern because such aircraft produce nitric oxide, NO, as a byproduct in the exhaust of their engines. Nitric oxide reacts with ozone, and it has been suggested that this could contribute to depletion of the ozone layer. The reaction NO+O3NO2+O2 is first order with respect to both NO and O3 with a rate constant of 2.20107 L/mol/s. What is the instantaneous rate of disappearance of NO when [NO]=3.3106 M and [O3]=5.9107M?

The Raschig reaction produces the industrially important reducing agent hydrazine, N2H4, from ammonia, NH3, and hypochlorite ion, OCl−, in basic aqueous solution. A proposed mechanism is Step 1: Step 2: Step 3: What is the overall stoichiometric equation? Which step is rate-limiting? What reaction intermediates are involved? What rate law is predicted by this mechanism?

Explain why half-lives are not normally used to describe reactions other than first order.

One possible mechanism for the decomposition of nitryl chloride, NO2CI, is What is the overall reaction? What rate law would be derived from this mechanism? What effect does increasing the concentration of the product NO2 have on the reaction rate?

The decomposition of NO2(g) occurs by the following bimolecular elementary reaction: 2NO2(g)2NO(g)+O2(g) The rate constant at 273 K is 2.3 1012 L/mol s, and the activation energy is 111 kJ/mol. How long will it take for the concentration of NO2(g) to decrease from an initial partial pressure of 2.5 atm to 1.5 atm at 500. K? Assume ideal gas behavior.

The hydrolysis of the sugar sucrose to the sugars glucose and fructose, C12H22O11+H2OC6H12O6+C6H12O6 follows a first-order rate equation for the disappearance of sucrose: Rate =k[C12H22O11] (The products of the reaction, glucose and fructose, have the same molecular formulas but differ in the arrangement of the atoms in their molecules.) (a) In neutral solution, k=2.11011s1 at 27 C and 8.51011s1 at 37 C. Determine the activation energy, the frequency factor, and the rate constant for this equation at 47 C (assuming the kinetics remain consistent with the Arrhenius equation at this temperature). (b) When a solution of sucrose with an initial concentration of 0.150 M reaches equilibrium, the concentration of sucrose is 1.65107M . How long will it take the solution to reach equilibrium at 27 C in the absence of a catalyst? Because the concentration of sucrose at equilibrium is so low, assume that the reaction is irreversible. (c) Why does assuming that the reaction is irreversible simplify the calculation in pan (b)?

The frequency factor A is 6.31 108 L mol1 s1 and the activation energy is 10. kJ/mol for the gas-phase reaction NO(g)+O3(g)NO2(g)+O2(g) which is important in the chemistry of stratospheric ozone depletion. (a) Calculate the rate constant for this reaction at 370. K. (b) Assuming that this is an elementary reaction, calculate the rate of the reaction at 370. K if [NO] = 0.0010 M and [O3] = 0.00050 M.