Reference no: EM131712425
1) Select all of the factors which affect the rates of chemical reactions.
- temperature
- catalysts
- relative energy of the products and the reactants
- concentration of the reactants
- stoichiometry of the reaction
- nature of the reactants
- contact between the reactants
2) The rate law for the decomposition of N2O5 is Rate = k[N2O5].
If k = 1.0 x 10-5 s-1, what is the reaction rate when the N2O5 concentration is 0.0017 mol L-1? (Exponents are entered using the notation 1.0E-5.)
3) If the reaction rate doubles when the concentration of a reactant is doubled, the reaction is ? order with respect to that reactant.
4) If the concentration of a reactant is trebled, by what factor will the rate increase if the reaction is second order with respect to that reactant?
5) The rate law equation for the reaction NO + O3 NO2 + O2 is Rate = k[NO][O3]. What is the reaction order with respect to NO and O3 and what is the overall rate order?
- The reaction is ? order with respect to NO.
- The reaction is ? order with respect to O3.
- The reaction is ? order overall
6) In a first order reaction with k = 4.7 x 10-3 s-1, if the initial concentration of reactant A is 0.5 mol L-1, how long will it take for the concentration of A to decrease to 0.1 mol L-1?
7) The term half-life, as applied to a reactant in a chemical reaction means:(which one is correct)
- the value of time which gives a value of 1/2 when substituted into the expression kt.
- half of the time it takes for all of a reactant to be consumed.
- the time required for half of the maximum amount of product to be formed.
- the time taken for the concentration of a reactant to decrease by a factor of 1/2.
8) Cesium-137 has a half-life of 30 years. How long (in years) will it take for all of the cesium-137 presently on Earth to be reduced to 1/32nd of its present amount?
9) If the half-life of a radio-isotope Z is 30 minutes, the decay process is first order and the initial concentration of Z is 2 μmol L-1, what is the concentration of Z after 2 hours?